Radiotherapy and Hybrid Imaging

Transcription

1 diothpy nd Hybid Imging Submittd by Tvo Lyndn Ackly B.Sc. [Hons], M. App. Sci. A thsis submittd in totl fulfilmnt of th quimnt fo th dg of Docto of Philosophy School of Mdicl Scincs Scinc, Engining nd Tchnoy Potfolio MIT Univsity Bundoo, Mlboun Victoi 3 Austli Dcmb i

2 Dcltion Dcltion I mk h ittn dcltion tht, xcpt h du cknoldgmnt hs bn md, this thsis is my ok lon; tht this thsis hs not bn submittd pviously, in hol o in pt, to qulify fo ny oth cdmic d; tht th contnt of th thsis is th sult of ok hich hs bn cid sinc th officil commncmnt dt of th ppovd sch pogm; nd ny ditoil ok, pid o unpid, cid out by thid pty in th pption of this ok hs bn cknoldgd, nd tht thics pocdus nd guidlins hv bn follod. Tvo Lyndn Ackly // ii

3 Acknoldgmnts Acknoldgmnts Fistly, I ould lik to thnk my MIT supviso, Associt Pofsso Moshi Gso, fo his psvnc nd ncougmnt ithout hich this ok ould not hv bn possibl. I ould lso lik to thnk ll of th MIT stff nd studnts tht I hv bn in contct ith ov th ys tht I undtook this ok. I xpss vy spcil thnks to D. Gm O Kf, hd of physics nd computing t th Austin Hlth Cnt fo PET, ho vy gnously tught m th bsics of PET nd imging. I ould lso lik to thnk ll of th stff nd studnts t th Cnt fo PET tht hlpd m long th y. Thnks du to Buc Vn Evy nd uth Mtin fom th Nucl Mdicin dptmnt of th Alfd Hospitl, fo thi hlp nd ssistnc. Th fist inspition fo this ok s th sult of intction ith th PET cnt t th Pt McCllum Cnc Institut, nd I ould lik to xpss my thnks to Pofsso od Hicks nd Dvid Binns nd ll of th stff t th PET cnt. Thy didn t hv to giv m ccss to thi imging dt, but thy did, nd it s to ou mutul dvntg. I must lso xpss my gtitud to ll of th stff t Ptmc Physicl Scincs Dptmnt nd t th Willim Bucklnd diothpy Cnt, spcilly Cig Lncst nd Kthln oxby fo thi pts. A spcil od of thnks must go to D. Jing Fng H, ho ys go skd m to poof d his thsis, nd in doing so shod m fo th fist tim, by th xmpl of his hd ok nd ddiction, tht this might ctully b somthing tht could b ccomplishd. Th lcom distctions of my dughts Dnill nd Smnth, ho butiful nd nv do nything ong, hv don most to sustin m long th y. My stpson Alxnd md th most insightful fmily contibution hn h simply skd Why? Fo my if Jnny, I simply do not kno ht to it. I ill lys b indbtd to my pnts, my moth nd my lt fth. I hd to go up nd hv childn of my on bfo I could fully ppcit my moth s ol. Fo my fth, I count th most pt dsciption of his ol s it cm to m. A collgu of my fth, t cmony to mk my fth s pssing, skd of m ht h s lik s fth. I bgn by sying tht ll of th kids ctinly got btt stt in lif thn h did. My fth s collgu finishd it by sying Wll tht sys it ll, dosn t it. iii

4 Tbl of Contnts Tbl of contnts Titl pg: diothpy nd Hybid Imging i Dcltion ii Acknoldgmnts iii Tbl of contnts iv List of Figus v List of Tbls x List of bbvitions xii Summy xvii Chpt : Plud Chpt : Sgmnttion 55 Chpt 3: Infomtion Tnsf 9 Chpt 4: gisttion to th ttmnt isocnt 87 Chpt 5: Syngy 39 A dtild contnts is givn t th stt of ch chpt. iv

5 List of Figus List of Figus Figu No. Pg No Chpt.5.- Th PET mission scn in th TPS disply Co-gistd tnsmission scn fom PET cm..5.- constuctd coonl slic Imgs tkn fom th TPS oksttion Zoom of th cvity (nst nighbou intpoltion) Clos up of th cntl cvity (bilin intpoltion).5.5- PET dt slic lvl PET dt slic lvl PET dt slic lvl Disct fiducils (sgittl) Disct fiducils (ltl) On of th svn disct fiducils Supio-ntio vi of fom suppot Ltl vi of fom suppot Coonl vi of PET tnsmission img PET ngtiv tumou xtnsion PET mission study:osophgl cnc.6.- PET img vid in th TPS Bm s y vi pojction of PET/CT nd CT PTVs Ptint E. Cumultiv dos volum histogms Flo digm outlining study schm Compison of ttmnt plns GTV-PET nd GTV-CT osophgl cnc Fil tnsltion schmtic Stuctu fo Fil Mt Hd Stuctu fo DICOM Dfult Tnsf Syntx Ictl SPECT dt 45 Chpt.4- Sph sufc nighbouhood Img vlu t cnt of sph Cylindicl pol coodints Img vlu t sph sufc Thshold tio Vition of sidul fom fit to Edi s dt Modlling of Edi Thshold tios (lin x xis) Modlling of Edi Thshold tios (ithmic x xi) ltiv dil function 8 v

6 List of Figus.7.- Thshold SUV vs Mn SUV Fits to Blck s dt Som tumous do hv shps tht ppoximt sphicl shll Avg vlu ov volum of sphicl shll.7.8- Vition of thsholds fo sphicl shll ith constnt vg Volum tio fo sphicl shll ith constnt vg dil xpnsion of shll 3.8- CT-PET imgs uplodd into th TPS FDG sph imgs impotd into th TPS Vition of cntoid of cc sph in x xis Vition of cntoid of cc sph in y xis Vition of cntoid of cc sph in Z xis Positionl o of cicul fiducil dil qution pdiction fo cc sph Obsvd dil distibution gph fo cc sph Thoy vsus xpimnt Pobbility distibution fo th mximum.- PET isosufc visuliztion 6..- CT slic though th PET phntom D Thsholds vs Mn FWHM.65 cm Expimntlly obsvd dil ltion Chpt Focl Es nding of unifom intnsity synthtic PET img Intposing hub btn DICOM p nd ntok Wishk llos utomtic disply limitd to DICOM Stg : No DICOM ctivity Stg : No DICOM ctivity Stg 4: Subsqunt to th DICOM ssocition qust bing civd Stg 8: Th TPS disply is updtd to sho lyd list of ptints Stg :Lyd list of ptints, studis, sis nd no imgs Stg :Impot/Expot summy disply Stg 5:TPS disply vts to min indo Th ppnc of th A7 o in th ishk intfc Th ASSOCIATE-Q pckt Elmnt : MAC Hd Elmnt : Intnt Hd Elmnt 3: TCP Hd Elmnt 4: PDU Typ Elmnt 5: svd Byt Elmnt 6: PDU-lngth Elmnt 7: Potocol-vsion Elmnt 8: Clld AE-Titl 54 vi

7 List of Figus 3..- Elmnt 9: Clling AE-Titl Elmnt : Itm-typ Elmnt : Itm-lngth Elmnt : Appliction-contxt-nm Elmnt 3: Psnttion-contxt-ID Elmnt 4: Abstct-syntx-nm Elmnt 5: Tnsf syntx nm Elmnt 6: Mximum lngth civd Elmnt 7: Implmnttion Clss UID Elmnt 8: Implmnttion vsion nm Th ASSOCIATE-AC pckt Elmnt 4: PDU fo ASSOCIATE-AC Elmnt 5: PDU lngth fo ASSOCIATE-AC Elmnt 9: svd non zo byts (Clld AE-Titl) Elmnt : svd non zo byts (Clling AE-Titl) Elmnt : sult/son Elmnt 5: Tnsf syntx nm (suppotd) Elmnt : Itm-typ (ASSOCIATE-AC) Elmnt 6: Mximum lngth (ASSOCIATE-AC) Elmnt 7: Implmnttion clss UID (ssocition ccpto) Elmnt 8: Implnttion vsion nm (ssocition ccpto) Th okound solution using DICOM pt 67 Chpt Th IGS ttmnt oom nd CT quipmnt Th IGS quipmnt in th lin cclto Linc contol oom IGS hd IGS ttmnt oom uxiliy instlltions On of th floo css mountd kv x-y tubs On of th oof mountd kv x-y img systms Img of cm dio-opqu ul HD chck position souc ul IGS opticl sub systm oof mountd infd dtction systm Th IGS opticl sub systm clibtion phntom Clibtion phntom lignd to oom lss Clibtion of th x-y systm Stp of th hiddn tgt tst Stp of th hiddn tgt tst A clos up of th TAPO, shoing th V pttn fiducils Stg 3 of hiddn tgt tst Stg 4 of hiddn tgt tst Stg 5 of hiddn tgt tst Stg 6 of hiddn tgt tst 3 vii

8 Stg 7 of hiddn tgt tst Stg 8 of hiddn tgt tst Fmlss stotctic ttmnt dcision pth Th l old coodint systm Th lins fom th kv soucs t 9 dgs vid bov Th to kv soucs not othogonl Th lin cclto: coodint systms 4.8- Histogm of tgt displcmnts ST pss t ST mximum pss t Binomil vsus Mont Clo o bs Vition of λ A ith dlt Vition of ST pss tio ith ccptnc thshold ST vition of σ i ith dlt ST vition of σ i ith dlt (xplodd vi) ST vition of σ j ith dlt ST vition of σ j ith dlt (xplodd vi) ST vition of σ k ith dlt ST vition of σ k ith dlt (xplodd vi) ST vition of confidnc ith pss citi i xis positionl ccucy vs pss conditions j xis positionl ccucy vs pss conditions k xis positionl ccucy vs pss conditions ST initil subgoups vition of i xis positionl ccucy ST initil subgoups vition of j xis positionl ccucy ST initil subgoups vition of k xis slf consistncy ST initil subgoups vition of dil o ST post ottionl subgoups vition of i xis positionl ccucy ST post ottionl subgoups vition of j xis positionl ccucy ST post ottionl subgoups vition of k xis slf consistncy ST post ottionl subgoups vition of dil o distnc movd vs distnc o bsdi vs 3D mov ST ST bsdj vs distnc movd ST bsdk vs distnc movd bsdi vs di ST bsdj vs di bsdk vs di ST ST bsdi vs dj ST bsdj vs dj 55 viii List of Figus

9 4..- ST bsdk vs dj ST bsdi vs dk ST bsdj vs dk ST bsdk vs dk ST vs di ST vs dj ST vs dk distnc movd vs distnc o SS bsdi vs 3D mov SS SS bsdj vs distnc movd SS bsdk vs distnc movd bsdi vs di SS SS bsdj vs di SS bsdk vs di SS SS bsdi vs dj SS bsdj vs dj SS bsdk vs dj SS bsdi vs dk SS bsdj vs dk SS bsdk vs dk SS vs di SS vs dj SS vs dk σ i vsus fction σ j vsus fction σ k vsus fction Vition of σ i ith fction split Vition of σ j ith fction split Vition of σ k ith fction split σ i ST influnc of fction numb σ j ST influnc of fction numb σ k ST influnc of fction numb Chck of coltion cofficint fomul 87 List of Figus ix

10 List of Tbls List of Tbls Tbl No. Pg No Chpt.5.3- Individul vlus t gid vtics in figu CAT dt lmnts of us fo co-gisttion Ovll ffct of PET on ttmnt pln FDG PET findings tht ltd clinicl stging nd ttmnt intnt 39 Chpt.5.4- Modlling of Edi thshold dt Modlling of Edi thshold dt including voxlistion FWHM.65 mn Modlling of Edi thshold dt including voxlistion FWHM.5 mn Gdint vlus pdictd by qution Mtch to Edi dt including nois.- PET scnn img pmts 5..- Edi thsholds 7.- Bmbill s sults Chpt Th stuctu of th TCP hd Th stuctu of th IP hd Th stuctu of th MAC hd PACS squntil infomtion tnsf summy Dcoding th CT scnn DICOM Upp Mssg Ly Dcoding th DICOM Mssg ly fo th simulto SIMULATO BASIC FILM SESSION N-CEATE ATTIBUTE LIST SIMULATO BASIC FILM BOX N-CEATE ATTIBUTE LIST SIMULATO BASIC GEYSCALE IMAGE BOX N-SET Q ASSOCIATED BY STUDY OOT QUEY ETIEVE Q PACS EPLY Q ASSOCIATED BY STUDY OOT QUEY ETIEVE Q PACS EPLY Q3 ASSOCIATED BY STUDY OOT QUEY ETIEVE Q3 PACS EPLY Q4 ASSOCIATED BY STUDY OOT QUEY ETIEVE Q5 ASSOCIATED BY STUDY OOT QUEY ETIEVE Q6 ASSOCIATED BY STUDY OOT QUEY ETIEVE Q7 ASSOCIATED BY STUDY OOT QUEY ETIEVE Q8 ASSOCIATED BY PATIENT OOT QUEY ETIEVE Q9 ASSOCIATED BY PATIENT OOT QUEY ETIEVE Q ASSOCIATED BY PATIENT OOT QUEY ETIEVE Q ASSOCIATED BY PATIENT OOT QUEY ETIEVE 8 x

11 Q ASSOCIATED BY PATIENT OOT QUEY ETIEVE Q3 ASSOCIATED BY STUDY OOT QUEY ETIEVE Q3 PACS EPLY Q4 ASSOCIATED BY STUDY OOT QUEY ETIEVE 83 Chpt Mn nd stndd dvitions of th sults potd by th IGS Infd stndd dvitions of th IGS vlus Comptmnts of ST dt fo λ A Pobbilitis of dvitions gt thn.5 nd mm Vition of pss t pcntgs ith diffnt numb of coctions Lg tnsltion initil stups not significntly os Sigm vlus fo long nd shot coctions ST lin fits SS lin fits Effct of optimistion Optimisd offsts Couch indpndnt tfcts Angul slf consistncy of ExcTc 8 List of Tbls xi

12 List of Abbvitions List of Abbvitions -D To dimnsionl 3-D Th dimnsionl 4-D Fou dimnsionl, mo coctly spitoy gtd 3D 6D Six Dimnsionl, mo coctly igid Body Tnsfom AAPM Amicn Assocition of Physicists in Mdicin ADAC ADAC Lbotois, Milpits, CA AH Tn in hxdciml nottion (H is suffix dnoting hxdciml, A is ) ANSI Amicn Ntionl Stndds Institut ANT Antio ANTHOP Anthopomophic phntom: ANDO phntom AP Antio to Postio AMC Austin ptition Mdicl Cnt ASCII Amicn Stndd Cod fo Infomtion Intchng ATTN Attnution coctd (DICOM) BAT B-mod Acquisition nd Tgting BH Elvn in hxdciml nottion (H is suffix dnoting hxdciml, B is ) BW Bon obt Wlls (Nuosugicl hd ing nd stotctic loclis) C-FIND Commnd to find (DICOM) C-FIND SP spons to quy/tiv qust (DICOM) C-GET Commnd to b snt (DICOM) C-MOVE Commnd to snd to thid pty (DICOM) C-PET Philips Mdicl Systms C-PET ddictd PET scnn CADPET CADPLAN ith PET (Autho s pogm nm) CADPLAN Comput Aidd Dsign Plnning (VAIAN TPS Bnd Nm) CAT Comput Aidd dition Thpy cc cubic cntimts CD-OM Compct Disc d-only Mmoy CH Tlv in hxdciml nottion (H is suffix dnoting hxdciml, C is ) CMS Computizd Mdicl Systms CT Computd Tomogphy CW Congstion Windo ducd DECY Dcy coctd (DICOM) DH Thitn in hxdciml nottion (H is suffix dnoting hxdciml, D is 3) xii

13 List of Abbvitions DICOM Digitl Imging Communiction in Mdicin DICOMDI DICOM Dictoy, dtbs fil of imgs in fil st (DICOM) DOS Disk Opting Systm D Digitlly constuctd diogph DTIM Dd Tim Coctd (DICOM) DVH Dos Volum Histogm DVTK Dicom Vifiction Tool Kit ECOG Estn Cooptiv Oncoy Goup EH Foutn in hxdciml nottion (H is suffix dnoting hxdciml, E is 4) EUS Endoscopic Ultsound F8 Fluoin 8 FDG FluoDoxyGlucos FH Fiftn in hxdciml nottion (H is suffix dnoting hxdciml, F is 5) FINDSCU FIND Svic Clss Us Appliction (DICOM-OFFIS) FOV Fild of Vi FWHM Full Width t Hlf Mximum GE Gnl Elctic GTV Goss Tumou Volum Gy Gy (Unit of Dos) Gy/min Gy p minut HD High Dos t (Bchythpy) HFS Hd Fist Supin HU Hounsfild Unit ICU Intntionl Commission on dition Units nd Msumnts ID Idntifiction (scop xcluds sction.) ID Intnl dimt (scop limitd to sction.) IEC Intntionl Elctotchnicl Commission IGT Img guidd diothpy IGS Img Guidnc Systm: BinLb ExcTc IMT Intnsity Modultd dition Thpy IOD Infomtion Objct Dfinition IP Intnt Potocol I Inf d ISO Intntionl Ognistion fo Stnddistion IT Infomtion Tchnoy xiii

14 List of Abbvitions ITM Ittiv Thshold Mthod kcps kilo counts p scond kv kilo lcton Volts kvp Dsignts mximum ngy of bmssthlung spctum in kv. L- Lft to ight LAT Ltl (ExcTc coodint nd couch movmnt) LLL Lft lo lob (of lung) LONG Longitudinl (ExcTc coodint nd couch movmnt) LUL Lft upp lob (of lung) M No distnt mtstsis M Distnt mtstsis M Mtstsis in clic lymph nod (lo thocic osophgus tumou) o M Mtstsis in cvicl lymph nods (upp thocic osophgus tumou) Mb Oth distnt mtstsis (not M) ma milli Amps MAC Mdi Accss Contol MV Million lcton Volts M Mgntic sonnc (DICOM dsignto fo MI) MI Mgntic sonnc Imging MV Dsignts mximum ngy of bmssthlung spctum in MV N No gionl lymph nod mtstsis N gionl lymph nod mtstsis N IIIA Diss Stg (Lung) TNM, TNM, o T3NM N3 IIIB Diss Stg (Lung) Any T, N3M NCE Ngtiv clssifiction o NOM Dtcto nomliztion coctd (DICOM) NM Nucl Mdicin NSCLC Non Smll Cll Lung Cnc OK Oky, sttus positiv, ffimtiv choic OSI Opn Systms Intconnction PA-AP Postio to Antio nd Antio to Postio PACS Pictu Achivl nd Communiction Systm PC Psonl Comput PDU Pogm Dt Unit (DICOM) P-DATA-TF Psnttion Dt Tnsf Fgmnt (DICOM) xiv

15 List of Abbvitions PET Positon Emission Tomogphy PCE Positiv clibtion o PTV Plnning Tgt Volum PMCI Pt McCllum Cnc Institut QA Qulity Assunc ADL non unifom dil smpling coctd (DICOM) AMLA o Action Mximum Liklihood Algoithm AN ndoms coctd (DICOM) ANDO An nthopomophic phntom compisd of plstic toso ncsing sklton AW AW img fomt, fil contins only img pixl vlus. ML ight middl lob (of lung) OI gion of intst T diothpy TOG diothpy Oncoy Goup TPS diothpy ttmnt plnning systm UL ight upp lob (of lung) SCAT Sctt coctd (DICOM) SCP Svic Clss Povid (DICOM) SCU Svic Clss Us (DICOM) SN Stnl Notch SOP Svic Objct Pi (DICOM) SPECT Singl Photon Emission Computd Tomogphy SS Stotctic diosugy ST Stotctic diothpy STOESCP Stog Svic Clss Povid Appliction (OFFIS-DICOM) STOESCU Stog Svic Clss Us Appliction (OFFIS-DICOM) SUP Supio SUV Stnddizd uptk vlu TAPO Tgt Position Loclis TCP Tnsmission Contol Potocol Tx Pimy tumou stg cnnot b ssssd TxNM Tx, No gionl lymph nod mtstsis, No distnt mtstsis TxNM Tx, No gionl lymph nod mtstsis, Distnt mtstsis TxNM Tx, gionl lymph nod mtstsis, No distnt mtstsis TxNM Tx, gionl lymph nod mtstsis, Distnt mtstsis xv

16 UID U V v V3 Vl Ln Vl p VET V WBC Uniqu Idntifi (DICOM) Uniqu cod pcntg of th totl lung civing Gy o mo volum of lung civing Gy o mo volum of liv civing gt thn 3 Gy. Vlu Lngth (DICOM) Vlu psnttion (DICOM) Vticl (ExcTc Coodint nd couch movmnt) Vlu psnttion (DICOM) Willim Bucklnd diothpy Cnt List of Abbvitions xvi

17 Summy Summy Cnc is cllul diss. In consqunc, th mngmnt of cnc idlly quis ccss to mthod of imging tht idntifis nd locts vy cncous cll in th ptint s body, coupld ith ttmnt modlity tht cn xclusivly tgt individul clls. In pctic, th bst sptil ccucy in xtnl bm diothpy is bout millimt, bout tims lg thn th siz of cll, so xclusivly tgting singl cll is not possibl in xtnl bm diothpy. Th kst link in th hol pocss is, hov, not ttmnt, but imging, not bcus of th limits of sptil solution, hich btt fo imging thn fo ttmnt, but bcus it is vy hd to dtmin fom stndd ntomicl imging h th tumou is. It is much si to s ht th tumou my hv don, in tms of disuption to blood vssls, osion of bons, nd s of incsd dnsity in lung tissu, but this dos not ncssily ccutly indict th loction nd xtnt of th tumou. Antomicl imging dtcts th diffnt ttnution of tissus ithin th humn body, nd so dos llo ccut gisttion of ttmnt bms to ntomicl lndmks such s bons, but this dos not ncssily mn tht th tumou itslf is ccutly loclisd. Functionl imging lis on th injction nd uptk of bioicl molculs tht hv bn lblld ith dioctiv isotop. Whn ths dioctiv isotops dcy, thy mit dition, nd functionl imging cn dtct individul tom dcy vnts, hich mks it th closst thing to cllul imging vilbl. Unfotuntly, th imgs must b built up of mny such vnts, noisy, nd hv sptil solution os thn tht of ntomicl imging nd vn ttmnt sptil loclistion cpbilitis. A dioctivly lblld glucos molcul hs th cpbility to sho th incsd uptk of glucos typicl of highly mtboliclly ctiv tumous, nd so hs th cpcity to sho ht tumou is cuntly doing, th thn ht it hs don. Antomicl nd functionl imging thus psnt diffnt but complmnty infomtion, to th xtnt tht viing physicin ill oftn quy th sptil gisttion of th to imging modlitis. It is ntul to ddss this cisis of clinicl confidnc in th gisttion btn ntomicl nd functionl imging by cquiing both in singl imging sssion, ithout th ptint moving fom th imging couch, nd dvics built fo tht pupos tmd hybid imging dvics. Th utho s fotunt to b bl to mk psonl contibution to th intoduction of functionl imging t cnc cnt, t tim hn th us of functionl imging in diothpy s f fom idspd. Th utho dvlopd mthod to incopot functionl imging, co-gistd ith ntomicl imging using fiducils, into diothpy xvii

18 Summy ttmnt plnning systm dsignd only fo ntomicl imging. This bsic nbling ok undpinnd th us of functionl imging fo clinicl ttmnt of lung tumous nd osophgl tumous guidd by functionl imging. Subsquntly th utho dvlopd futh dpttion of this systm to llo us of functionl imging fo tgting intcnil diothpy ttmnt. Th utho s, fist hnd, th cuing poblms bcom ppnt. Fistly, th s no cl consnsus on ho to sgmnt tumou fom functionl imgs. Scondly, mny poblms of infomtion tnsf ncountd, nd mthod s quid to llo ths poblms to b ddssd. Thidly, it s not nough to hv functionl imging co-gistd ith ntomicl imging t th tim of cquisition, it s lso ncssy to stblish noth gisttion, to th ttmnt isocnt in th diothpy cnt, mot fom th imging cnt nd t subsqunt tim. Chpt lts this xpinc nd ths obsvtions, ding fom thm to st th diction nd thm of th thsis. Chpt lts to th fist poblm, nd bgins ith vi of th littu of tumou sgmnttion fom functionl imging. Th ok thn dls ith th most idlisd bsic poblm of functionl tumou sgmnttion, sphicl, sttiony tumou ith unifom isotop uptk. A simpl modl of functionl imging s Gussin bluing of th objct s pplid, nd subsquntly ptubtion fo img nois s ddd. Th mny shot xplntions in th littu of functionl imging tht scib pticul ffcts s consquncs of sptil bluing nd nois vious ffcts, but mo igoous, modl bsd dtmintion of th obsvtions tht ths to ffcts could xplin s undtkn. Applying th modl involvd diving qutions to clcult thshold vlus, hich thn compd to vlus in th littu tht xpimntlly obtind, vlus tht undpin divs clinicl tils ith D PET imging. Futh qutions divd to xplo th limittions of thshold of th tumou vg pplid to non sphicl gomty. Th chpt concluds ith dmonsttion of th limittions of th modl hn pplid to 3D PET. It is shon tht ltiv thshold mthods cnnot diffntit btn sphs of diffnt volum blo volum of bout cubic cntimts. Chpt 3 stblishs th thoticl bsis of mthod fo solving poblms ith infomtion tnsf, nd thn shos ho it cn b pplid in pctic by fnc to th clinicl xmpls. Th fist xmpl is th suddn filu of PACS systm, h this mthod is usd to solv th cus of filu. Th scond xmpl is th discovy of n undlying fult ith n xisting diothpy ttmnt plnning systm tht ndd it unbl to civ imgs, h th mthod is usd to implmnt solution ithout ny xviii

19 Summy intuption to clinicl ctivity. Th thid xmpl is mlfunction in th poduction of hdcopy img quid fo xisting ttmnt pocsss, h th mthod s usd to solv poblm tht s othis intctbl. Th ok psntd is distilltion of mny ys of pption, nd hd xpinc of solving mny poblms. Chpt 4 dls ith th poblm of gisttion to th ttmnt isocnt, fist viing th gnl cpbilitis in th fild, nd thn focussing on th pocdus ssocitd ith kilovoltg x-y loclistion tchniqu. Th pincipl of ottionl invinc is pplid to div mthod of sttisticl infnc to vify th sptil ccucy of th systm in clinicl pctic, using only th sults obtind s pt of tht clinicl pctic. Th most impotnt sult s to pov tht th systm s sufficintly ccut in clinicl pctic. Additionlly, chngs to clinicl pctic (imging t to couch ngls bfo ttmnt) tht ould nhnc tht ccucy dtmind nd implmntd. Estimts of th diminishing tuns in clinicl ccucy xpctd s sult of ducing positionl tolncs dtmind. Th mthod s lso usd to dtmin th vlidity of to clinicl pocdul obsvbls, fistly th numb of coctions quid fo n isocnt plcmnt nd scondly th distnc movd in th lst coction, s indictos of supio o infio gisttion ccucy. Th mthod divd in chpt 4 is univslly pplicbl in ny diothpy cnt using th dscibd kilovoltg x-y loclistion tchniqu. Chpt 5 bifly ds togth th sults fom chpts -4 to povid n ovll conclusion to th ok, nd to mphsiz th coupld ntu of th th dispt poblms ith spct to th idspd clinicl implmnttion of diothpy nd hybid imging. This ok povids novl but univslly pplicbl mthod fo vifying th ccucy in clinicl pctic of kilovoltg x-y loclistion tchniqu. No spcil quipmnt is quid, no is ny xt dition dos quid. Th kilovoltg x-y loclistion tchniqu dos not qui volumtic CT scn cquid in th ttmnt oom, but cn utilis CT scn cquid nyh, including on cquid in mot nucl mdicin dptmnt s pt of hybid imging study. Th innt co-gisttion of functionl nd ntomic imging povidd by hybid imging is thus nhncd by bing vifibly gistd to th diothpy ttmnt isocnt. Th kilovoltg x-y loclistion tchniqu is fficint, ccut nd cliniclly vifibl, but it lis on un-intuptd infomtion flo, fom th nucl mdicin dptmnt to th diothpy dptmnt. This flo cn b intuptd t ny tim, but this ok dmonstts tht th is n chivbl, hospitl bsd mthod to solv ths poblms, tht dos not qui ny spcilisd quipmnt. It hs bn shon thoticlly nd dmonsttd pcticlly tht it is possibl to intcpt nd nlys th DICOM infomtion xchng xix

20 Summy ithout ny vndo ssistnc, nd in som cicumstncs to implmnt solution of poblm loclly using vilbl soucs. Bfo considing poblms of gisttion o infomtion flo, th poblm of tumou sgmnttion fom functionl imging must b considd. In this ok only th simplst scnio hs bn considd, th sgmnttion of sphicl, sttiony, unifom concnttions of FDG. Th vidnc fo th clinicl vlu of FDG fo tumou volum mking is still bing gthd. Som of it lis on D-PET clinicl tils using diffnt sgmnttion thsholds. Wh ths tils pot conflicting sults, this ok povids mthod of stimting th impct of ths thsholds on sgmnttion. It is spcilly impotnt tht this mthod lis only on nois nd sptil chctistics, s ths gnlly ll chctisd in th vilbl littu. Ths tils qui significnt follo up piods of ys bfo th sults cn b publishd, duing hich tim mny so mny of th D PET units hv bn plcd by 3D PET units tht it my no long b possibl to dtmin th quid thsholds by dict xpimnt. Fo th 3D PET units, th idntifiction of lo volum thshold fo th pplicbility of ltiv thshold mthods dds n impotnt considtion to th ongoing clinicl dbt ov th comptiv vlu of ltiv vsus bsolut thshold mthods. Th is much to follo byond th ok in this thsis. Poblms of img sgmnttion fo functionl imging should b ddssd by cliniclly lvnt mthods, not constind by ht is possibl ith commcilly vilbl diothpy ttmnt plnning systms. Fo lg clinicl tils, clinicins should b povidd ith pupos dsignd pplictions to chiv tumou sgmnttion. Such pplictions should tk s input th DICOM output of hybid imging dvics, povid us intfc fo th clinicin to implmnt sgmnttion ccoding to th potocol, nd poduc s output DICOM T stuctu sts of th sgmntd tumou. This ill poduc mo unifom implmnttion of th til mthodoy, s ll s insulting th clinicin fom th complxity of th sgmnttion lgoithm. Implmnting such pplictions ill qui yt noth vulnbl link in th DICOM infomtion xchng. If th mthod of dling ith infomtion tnsf poblms tht th utho hs outlind is implmntd mo idly, th libility of such infomtion xchngs should gdully b impovd by btt solution of poblms lding ultimtly to mo libl pplictions, nd ultimtly mo obust stndd. Finlly, th mthod of vifying gisttion to isocnt dvlopd in this thsis is univslly pplicbl. If oth cnts pply this mthod, it ill b possibl to build up pofil of ccucy chivd by diffnt clinicl mthods. Evntully, cnts ill b bl to vi th xx

21 Summy littu to slct clinicl gisttion potocols ith ccucy tilod to th quimnts of th clinicl ppliction. xxi

22

23 Chpt Plud Chpt : Plud dioist: Th nxt cs is cunt lung cnc. Th CT scn shod n of consolidtion ithin th lung. This hs bn biopsid, nd is ngtiv fo cnc. I sk th dition Oncoist to dscib th diothpy ttmnt sttgy. dition Oncoist I ill tt th consolidtion dioist phps you mishd m, th consolidtion biopsy cm bck ngtiv dition Oncoist I ill tt th consolidtion you hv to go ith ht you kno. collctions fom lung clinic, 99. Contnts. Intoduction diothpy finmnts of tchnoy fo poducing dition Bsic thoy of diothpy Pcticl implmnttions nd dsign constints of diothpy Antomicl Imging Functionl imging PET Functionl imging SPECT Incopoting PET Imgs into diothpy Ttmnt Plnning in clinicl sch nvionmnt Mthod fo incopoting PET Phntom tsts Intpoltion Mdicl Img Fomts Applying th mthod in clinicl pctic Fiducil Alignmnt Systm Til Osophgl cnc... 9

24 Chpt : Plud.5.9 Gyscl Disply Cliniclly usful spcts of PET disply Clinicl Obsvtions Tchnicl summy....6 Lung Cnc Elligibility citi Acquisition of PET nd CT dt fo ttmnt plnning PET nd CT img cogisttion Contouing of GTV using CT lon nd CT plus PET Ction of th PTV nd ttmnt pln Compison of CT lon nd PET/CT divd ttmnt plns sults Ptint chctistics Effct of PET on th covg of th pimy tumou Effct of PET on covg of involvd lymph nods Influnc of PET scnning on PTV isk of gogphic miss Minimum doss in th PTV Effct on dos to noml lung Inspition Osophgl cnc Study Schm Ptint simultion nd cquisition of PET-CT dt sts Dlintion of tgt volums nd ttmnt plnning Pln Compison sults Imptus fo functionl imging fo contouing Ictl SPECT imgs Clinicl Pocdu Convsion fom AW fomt to DICOM Filst Fil Mt Infomtion Uniqu idntifis in th Fil Mt Infomtion DICOM Dt St Implmnttion c to implmnttion Ointtion of th img sts Dk ithin th SPECT dt Byt oding SPECT img sptil solution nd stotctic loclistion ccucy DICOM bodcst of SPECT dt vs. movbl mdi ction quimnt to scl th pixl vlus of th DICOM SPECT(CT)dt sts Outcom Motivtion Thsis stuctu...49

25 . Intoduction Chpt : Plud This subjct of this thsis is th syngy of diothpy nd Hybid Imging. diothpy is th us of ionizing dition fo ttmnt, most oftn of cnc. Hybid imging is th combintion of n ntomicl imging modlity, such s computd tomogphy (CT) scnn, nd functionl imging modlity, such s positon mission tomogphy (PET) scnn, to img ptint on th sm bd. This intoduction sks to dscib th fundmntls of diothpy nd hybid imging to sho hy it is cliniclly usful to combin thm. Th cs fo incopoting hybid imging into diothpy is md by folloing th uthos on ttmpts to do so. This involvd incopoting PET imgs into diothpy plnning systms, incopoting PET imgs fo tumou volum mking fo Lung Cnc ttmnt, incopoting PET imgs fo osophgl cnc tumou volum mking, nd finlly dpting singl photon mission tomogphy (SPECT noth fom of functionl imging) imgs into stotctic ttmnt plnning systm to guid idition to contol pilptic sizus. Th motivtion nd stuctu of this thsis; th nd to solv th th coupld poblms of thsholds, infomtion tnsf nd gisttion, dlt ith in sctions.9 nd. t th nd of th chpt.. diothpy diothpy is th us of dition s mdicl ttmnt. diothpy bgn in th old in th y of th discovy of x-ys by ontgn, 895, ith th fist codd ttmnt by Emil Gubbé, but it s not until th folloing y tht Fund bgn spcilty ttmnts 3, nd diothpy lso bgn in Austli s ly s ith ttmnts of skin disss. Sinc thn pogss hs bn divn by th min fctos, th finmnt of tchnoy fo poducing dition, th finmnt of imging tchnoy fo dtcting cnc, nd impovmnts in clinicl pctic sulting fom mpiicl obsvtion of th fficcy of diffnt diothpy ttmnts.. finmnts of tchnoy fo poducing dition. X-ys fist poducd by lctons ccltd by sttic lctic potntil colliding ith solid cthod, nd mitting photons s Bmssthlung o bking dition. Th ngy s limitd to mximum of bout thousnd lcton volts o kv. At ths ngis, th mximum dos fom dition occud t th ptint sufc. Subsquntly ng of cclting tchnois dvlopd using tim vying lctic filds nd o mgntic filds, such s th btton 5, lin cclto 6, nd synchoton 7. This llod fo poduction of x-ys of mximum ngy in th ng of 4-5 million lcton volts (MV). At ths ngis th mximum dos s dpositd t dpth of cm to 5 cm insid th ptint. This llod th ttmnt of dp tumous. Mthods volvd to impov th sptil ccucy of th ttmnt. Th highst ccucy chivd s fo tting intcnil lsions, using mthods of locliztion bood fom Nuosugy to fix th skull using nuosugicl fm. Indd th pion of stotctic diosugy (SS), s it cm to b clld, s Ls Lksll, himslf tind nuosugon. Th sptil ccucy is of th od of mm. 3

26 Chpt : Plud Th cunt stt of th t involvs th id clinicl us of multi lf collimtos, hich mov s th ptint is iditd to modult th intnsity of th dition. This tchniqu, tmd intnsity modultd dition thpy o IMT, llos th distibution of dos to b shpd to confom to th shp of th tumou. Sophistictd imging tchnoy hs bn intoducd into th diothpy ttmnt oom to llo locliztion of th ptint tumou on th dy of ttmnt, in th ttmnt position, momnts bfo th ttmnt commncs. Fo intcnil pplictions, this tchniqu cn chiv locliztion ccucy supio to nuosugicl fm bsd stotctic ttmnt s ll s hlving th ttmnt ppointmnt tim. This tchniqu is bodly tmd img guidd diothpy (IGT). All of ths pplictions lint on th vilbility of th dimnsionl (3-D) volumtic imging of th ptint... Bsic thoy of diothpy W consid h only x-y dition, lthough oth typs of dition usd in diothpy, such s lctons, nutons, potons, nd hvy ions. X-ys in clinicl diothpy us in Austli lmost xclusivly poducd by lctons stiking tgt, sulting in Bmssthlung dition. This poducs x-ys ith pticul ngy spctum nd ngul distibution. As th ngy incss, th x-y poduction is pkd in th fod diction. Th ngy spctum is oughly tingul, ith lo ngy photons bing mo likly. Thus th vg ngy of th spctum is bout on thid of th mximum ngy. Such spctum is dscibd by th mximum ngy of th spctum, hich lso cosponds to ngy of th lcton tht ctd th x-y. A bmssthlung ngy spctum ith mximum ngy of kilo lcton volts (kv) is dsigntd s kilo volt pk (kvp) bm. A bmssthlung spctum ith mximum ngy of 6 MV is dsigntd 6 MV bm. A 6 MV x-y bm hs hlf vlu thicknss of bout 5 cm in tissu, hich is to sy tht ft it hs tvld though 5 cm of tissu, only hlf th photons ill min un-ttnutd. This pnttiv po is th most usful qulity of x-ys fo thpy. It llos n intio tumou to b ttd non invsivly s n outptint svic. Whn th x-y psss though tissu, it intcts ith th tissu nd sts in motion lo ngy lctons nd somtims lcton positon pis. Ths chgd pticls cus ioniztion ithin th tissu, hich is th gncy by hich dition ffcts living clls. Th mount of ngy p unit of mtt dpositd in tissu by th x-ys is tmd th Dos of x-ys in tissu. Th ffct of dition on tissu incss monotoniclly ith Dos. Th unit of Dos is th Gy (Gy)... Pcticl implmnttions nd dsign constints of diothpy. Lin ccltos usd fo diothpy cn poduc dos t of ound 6 Gy p minut (Gy/min) t thi noml ttmnt distnc of mt fom th ptint. Th usul ttmnt tims of th od of sconds of bm tim, phps bokn into svl potls. Attnution of th x-y bm by th ptint nd /o bm modifis cn mn tht th ttmnt tim is long. 4

27 Chpt : Plud Th unit quis substntil shilding, nd th vguid cn b quit long. Th lin ccltos usully ott ound fixd point (th isocnt) to nominl ccucy of th od of mm..3 Antomicl Imging Whn only supficil tumous dtctbl, plption s sufficint to idntify thm. Th histoy of ntomicl imging bgn ith th fist diogph, in 896, of ontgn s if s hnd. Hounsfild s 8 invntion of th CT scnn in 947 llod visulistion of intnl ntomy in dimnsionl (-D) digitl fom. Cuntly multi slic CT scnns mk ntomicl imging ffctivly 3-D, ith cquisition spds fst nough to img bting ht, nd xil filds of vi lg nough to tc th movmnt of hol tumou ith spition. Th sptil solution cn b s fin s.65 mm in th xil dimnsion, nd.5 mm in th tnsxil pln. Antomicl imging lis on th ttnution of kvp x-ys. As th x-y tub otts ound th ptint, th CT scnn dtctos mk pln mp of th ttnution of x-ys fom ch diction. By solving th -D invs don tnsfom, mp of th x-y ttnution ithin th ptint is digitlly constuctd. Th invs don tnsfom cnnot b solvd loclly in n vn numb of dimnsions, so hn invting th -D don tnsfom it is ncssy to hv n ttnution mp tht spns th ptint. Tht is to sy, th x-y bm nd th dtcto bnk must b id thn th ptint. Attnuting objcts outsid th fild of vi othis constuctd s ing ound th outsid of th cicul fild of vi. Th idl ngy to opt th x-y tub t is of th od of kvp. At this ngy th photolctic ffct domints photon bsoption, hich is stongly dpndnt on tomic numb, so th img hs good lo contst solution. Th ngy givs th mximum ngl subtndd by th usful x-y bm s it mgs fom th x-y tub, nd this ith th idth of ptint spcifis th distnc tht th x-y tub hs to b fom ptint. This hs implictions fo th intnsity of x-y bm quid, nd th sptil solution, hich gts os s th tub movs futh y. To this complx intction of constints must lso b ddd th cost of th unit. Fotuntly du to th lg instlld bs, th dsigns hv bn optimizd to vy high dg. Th soft on th n CT scnns is so ll dvlopd, tht th ns to vy functionlity quy is ffimtiv, th difficult pt is ngotiting th mz of cpbilitis to dtmin hich on to ccss..4 Functionl imging Cnc is cllul diss, so th idl clinicl quimnt is to img individul clls. Unfotuntly n individul cll is too smll to b sn on ntomicl imgs. Th ttnution of singl cll is too smll fo stndd x-y img to disply it in i, much lss dtct th diffnc in x-y bsoption btn tumou cll nd non tumou cll. A singl tumou cll, o vn mico clust of tumou clls, cnnot b dtctd ith ntomicl imging. Th bst tht cn b chivd is to img stuctul consquncs of ht th tumou hs don, so fo 5

28 Chpt : Plud xmpl clcifictions in th bst, lkg of intvnous iodintd contst mdium into tissu on th piphy of tumous du to th dmg cusd to blood vssls, cting so clld ing nhncing lsions, nd tumous obstucting th bifucting iys of th bonchil t to poduc consolidtion in s of lung. Ths ll signs of ht th tumou hs don, nd giv no indiction of ht th tumou cuntly is doing. Convsly functionl imging is chivd by th intoduction of dio-lbld compounds into th body, hich cn thn b imgd hn thy dcy. Th compounds cn distibut in th xt-cllul o cllul spc, thy my b mtbolizd insid th cll, thy my b cld by th body, o thy my b pfntilly uptkn by th tumou clls. Th sptil solution is gnlly infio to ntomicl imging, nd th imgs vy noisy in compison lso, but th imging pptus ill dtct individul quntum vnts. So dcy of on singl lbld dionuclid molcul ithin singl cll ill contibut to th img. Thus functionl imging is th closst thing to cllul imging tht is vilbl..4. PET Positon Emission tomogphy lis on th intoduction into th body of compound lbld ith positon mitting dionuclid. Whn th dionuclid dcys, it mits positon, hich tvls though tissu bfo it nnihilts. Th distnc it tvls dpnds on th ngy of th positon, hich dpnds pinciplly on th isotop. Th lso ng stggling ffcts, but fo Fluoin 8 (F8) dcy positons this distnc is on vg mm. This sts limit on th bst sptil solution tht cn b chivd, bcus it is th positon nnihiltion tht is dtctd, not th F8 positon dcy itslf. Th positon nnihilts ith n lcton to poduc n nnihiltion pi of coincidnc photons. Ths photon pis thn dtctd by coincidnc dtctos ound th outsid of th body. Som of th photons ttnutd bfo thy ch th dtctos. Dpnding on ho much kintic ngy th positon hd, th photons do not tvl in xctly opposit dictions. Th sptil solution of th dtcto systm is lso limitd by cost, nd ths th fctos, th distnc nnihiltion, th lss thn opposit dictions of tvl of th photons, nd th solution of th dtcto systm, contibut mo o lss qully to poduc sptil solution of th od of 4mm. Th fist us of nnihiltion imging dts bck to dvlopmnt in th ly 95s 9, culminting in th dvlopmnt of th fist PET cm in 96. In Austli, th intoduction of PET cms bgn in 99 nd s stictly contolld. Instlltions initilly limitd to cnts tht undtook to un clinicl tils of PET imging. Th cunt stt of th t involvs PET cms ith solution of -4 mm, mountd in combintion ith PET scnn fo ttnution coction nd innt gisttion ith functionl imging. FluoDoxyGlucos (FDG) is usd s ll s mny oth mo sotic compounds fo ssying diffnt things such s tumou goth, but th compound most usd fo oncoy is FDG. FDG is glucos nu, ith dioctiv F8 tom plcing singl tom of oxygn. Axil filds of vi of up to 8 cm suppotd. PET is sttisticlly limitd mdium. If mo dioctiv compound is injctd, this incss th chnc of fls coincidncs o ndoms. It is not lys possibl to incs th img qulity by incsing th mount of dition injctd. 6

29 Chpt : Plud FDG is glucos nu, but it only pticipts in th fist stp of th mtbolic glucos cycl, nd FDG tht nts cll is gnlly tppd th s sult. This simplifis th comptmnt modl fo FDG. Ely PET imgs usd mtl spt to collimt th nnihiltion photons so tht ch ing of dtctos imgd singl slic, tmd -D PET. Subsquntly 3-D constuction lgoithms dvlopd, lloing un-collimtd dtcto ings to b usd to constuct cylindicl volum, tmd 3-D PET. 3-D PET llod th us of lo ctivity concnttions nd much fst img cquisition tims. F8 hs hlf lif of 9.74 minuts, img cquisitions thfo coctd fo dcy, spcilly if th xil fild of vi (FOV) is too smll nd th ptint must b movd to cqui full 3-D PET img. Gomtic considtions dictt tht th lins of spons, ppoximtly qully sptd in th cnt of th dtcto ing, ill b dns clos to th dtcto ing, cocting fo this is tmd non unifom dil smpling coction. Eith nnihiltion photon my fil to b dtctd bcus it intcts ithin th ptint bfo th dtctos, coction fo this ffct is tmd ttnution coction. Evn if thy do intct, scttd nnihiltion photon my still b dtctd in coincidnc ith its pid un-scttd nnihiltion photon. It ill thn b constuctd using n incoct bck pojction lin. This ffct is pticully impotnt in 3-D s opposd to -D PET. An img constuctd ith compnstion fo this sctt is tmd sctt coctd. Immditly ft dtcting n vnt th dtctos unbl to gist noth vnt fo shot piod of tim. An img constuctd ith compnstion fo this is tmd dd tim coctd. No mtt ho smll th coincidnc indo is st, som photons tht not fom th sm nnihiltion ill invitbly iv t diffnt dtctos ithin th coincidnc indo, ths vnts tmd ndoms, nd cocting fo thm in img constuction is clld ndoms coctd. Not ll lins of constuction dtctd ith unifom snsitivity du to vying ngl of incidnc on th dtcto nd individul dtcto chctistics, cocting fo this is tmd dtcto nomliztion coction..4. Functionl imging SPECT Singl photon mission computd tomogphy diffs fom PET in tht th isotop mits singl photon. Coincidnc counts not possibl, but bcus singl photon is mittd ith th dcy of th dionuclid, it ill hv dfind ngy. An ngy indo cn b usd to jct scttd photons. In thoy th sptil solution of SPECT could ivl tht of PET, but in pctic lck of dvlopmnt mns tht SPECT solution is ound 6-8 mm. SPECT dos hv th dvntg of lloing simultnous tcing of to dio-nuclids, though th us of diffnt isotops ith diffnt ngis, hich cn b usful fo simultnously tcing th distibution of to dugs. Th fist SPECT imgs obtind in 96, nd th cunt stt of th t hs pogssd to SPECT-CT scnns ith dignostic qulity multi slic CT scnns..5 Incopoting PET Imgs into diothpy Ttmnt Plnning in clinicl sch nvionmnt. As ll s impovd imging nd ttmnt tchnoy, diothpy hs dvncd though finmnts of clinicl tchniqu guidd by mpiicl vidnc, such s comptiv sttistics fom ivl ttmnt tchniqus. Futh 7

30 Chpt : Plud dvncmnt in clinicl sch quis th implmnttion of clinicl tils. On of contovsy is th us of PET FDG imging fo tumou volum mking. A vi of spcts of th utho s on involvmnt in on ly ndvo in this is includd to stblish th motivtion fo th inclusion of functionl imging in th diothpy pocss. Th Intntionl Commission on dition Units nd Msumnts (ICU) pot 6 idntifis th mking of tgt contous fom CT scns s th lgst contibuto to th globl unctinty of dition thpy ttmnt plnning, ding pimily on th ok of Lunns ith gd to nuoic css. Difficulty mking tgt volums fom CT scns is lso poblm in lung cnc 3,4. PET hd bn in us t Pt McCllum Cnc Institut (PMCI) sinc 996. It hd bn usd s clinicl stging tool, nd ptint mngmnt hd bn influncd by PET study sults. In ly, th diothpy dptmnt hld mting in th nticiption of th imminnt ls of systm to nbl impottion nd co-gisttion of PET img dt into 3D diothpy ttmnt plnning systm. Th mthodoy poposd s to us simpl systm of fiducils. It s intndd to duplict th ptint position t th CT scnn nd th PET scnn. In this y th poblm of co-gisttion ould b ducd to slcting th ppopit tnsltion fom on coodint systm to noth. Th chosn diothpy ttmnt plnning (CADPLAN, Vin Mdicl Systms, Plo Alto, USA) s slctd bcus th most likly clinicl sit s xpctd to b lung 5 nd it s th systm outinly usd fo lung plnning. Additionlly th img fomt nd ptint dt s ll documntd 6 nd in pticul th Comput Aidd dition Thpy (CAT) fomt of th img fils s ll undstood. Th s ldy xpinc of ding th CT fils fo stotctic loclistion 7 nd volum clcultions 8. It s xpctd tht it ould b possibl to sp th img in nd out of th CAT fils hil lving th img hd intct. This ould llo th mkd contous to b supimposd ov htv img dt s dsid..5. Mthod fo incopoting PET. Th vibility of this concpt s initilly tstd by simply spping in blnk img. It s found tht th diothpy ttmnt plnning systm (TPS) updtd ch img dict fom th CAT fil vy tim tht th us cusd th CT slic disply to b fshd. Thus it s possibl in th X Windo 9 nvionmnt to un spt pocss plll to th TPS, mnu bsd C pogm (CADPET) tht smpld th Digitl Imging Communiction in Mdicin (DICOM) PET img fil (Nucl Mdicin (NM) multislic fomt) nd ctd mtching co-gistd st of PET imgs in CAT fomt. Whn it s dsid to chng to PET disply in TPS, it s only ncssy to mov th mous point into th CADPET indo (Sn ith hding dtm on th middl lft of Figu.5.-), slct mnu itm to chng to PET img disply nd thn mov th mous bck to th lo TPS indo to slct slic nd updt th disply. Th mnu instuction inititd sis of lo lvl its of dt into ch nd vy tnsvs CAT fil fo tht ptint. Dspit th lg mount of dt tnsfd (About. mgbyts p slic) th tnsf s fst nough not to b noticd on n isoltd systm. In contst to xcut th sm volum it commnds coss th ntokd CADPLAN systm took - sconds noticbl 8

31 Chpt : Plud lg. Th pocss s vsibl nd in pctic uss found it convnint to chng btn PET nd CT mod svl tims ch slic s thy mkd tgt contous. Th TPS dictoy stuctu hd multipl ptints in ch dictoy. Fo ch ptint in dictoy, spt CAT fomt fil xistd fo ch tnsvs CT scn (s ll s fo vis in oth plns.). CADPET md list of ths fils tht ccssd by th TPS, nd ctd copy of ch of th tnsvs slics fo pticul ptint, togth ith th mtchd co-gistd PET CAT fomt fils. Th CAT fils ccssd by th TPS listd in dtbs fil in ch dictoy, but individul fils lso stmpd ith th ptint nm nd uniqu cod (U) numb in th hd, s ll s hving filnm divd fom th U numb nd th slic numb. Th xtnl pogm schd nomintd dictoy nd sotd th fils nd colltd th filnms by thi hd dt nd offd mnu choic listing vilbl ptints. Th PET dt fil lso ndd to b spcifid by th sm mthod. Subsquntly CADPET offd looping mnu lloing th us to sp btn PET nd CT dt disply. Although this pocss s dqut fo clinicl sch nvionmnt, it s cl tht mo univslly pplicbl, obust nd us findly mthod of infomtion tnsf ould b dvntgous fo outin clinicl us. At th outst of th pojct, th most common spons hn viing Figu.5.- s quy s to hy th phntom s not visibl, hich s flction of th pimcy of ntomicl th thn functionl imging in diothpy pctic t tht tim. Fig..5.- Th PET mission scn in th TPS disply. Th lft hnd img is tnsvs slic though th 8FDG lodd lin soucs. Not tht th middl of th fiducils blck bcus th signl is gt thn 3, t hich th TPS gyscl disply clocks ov. Th ight of scn fnc img is constuction of th coonl pln fom co-gistd xil mission slics. Not tht in both imgs, th ANTHOP phntom itslf is invisibl bcus it is not significnt souc of nnihiltion photons. Th lo indo is th stndd TPS contouing okspc indo. Sitching btn PET nd CT imgs is chivd by th CADPET pogm unning in th floting dtm indo..5. Phntom tsts. Th nxt stp ft poving th concpt s to obtin som PET dt using n nthopomophic phntom (ANDO, Aldson sch Lbotois, Stnfod, CN, USA). Flxibl lin soucs (tubs filld ith 8FDG) ttchd to th sid of th nthopomophic phntom (ANTHOP) fo PET nd CT scn. Figu.5.- shos th mission scn. Although th fiducil lin soucs clly visibl, th is no intnl ntomy visibl, sinc ANTHOP is not dioctiv. Th cnt of th fiducils blck th thn hit bcus th CADPLAN gyscl is intndd fo us ith CT vlus nd clocks ov t vlus ov 3. 9

32 Chpt : Plud Figu.5.- shos th tnsmission scn fom th PET cm. In od to pfom ttnution coction, th PET cm otts dioctiv souc ound th ptint to do poo img qulity CT scn. Th tnsmission dt is diffnt fom CT scn in numb of ys. It uss lg souc, hos ngy spctum is diffnt, nd th sptil solution is poo, but it dos hv th vitu of bing inntly co-gistd ith th mission scn. Fig Co-gistd tnsmission scn fom PET cm. Th smll cicls on th ntio nd ltl sufcs th outlins of th fiducils fom th PET mission scn. Th lung outlins fom th cogistd CT scn of th ANTHOP phntom. Th cosnss of th PET tnsmission scn cn b sn. Th hlo ffct t th i lung intfc is n tfct cusd by n img tnsltion poblm tht s md vidnt by th tnsmission scn. Using th PET mission fiducils, th PET mission scn s lind up ith th CT scn by simpl x,y,z shift. Th lignmnt s chckd by comping th lung contous fom th dignostic CT ith th co-gistd PET tnsmission dt. Th gmnt cn b vid in Figu.5.-. Th mjo knss of this systm is th lck of z snsitivity, so it s chngd to systm of disct fiducils fo ptint imgs. This is discussd in dtil in sction.5.6. Fig constuctd coonl slic clcultd fom co-gistd xil tnsmission scns using th stndd TPS img ction tool. Th ltl outlins th outlins of th lin soucs mkd on th cogistd PET mission scns. Th lins mking th lungs in th cnt of th thox divd fom cogistd CT scn dt, nd should coincid ith th dk gion in th tnsmission scn. It cn b sn tht th lin fiducils ltivly insnsitiv to supio infio displcmnt, s shon by th discpncy of th lung lvl. Th poblm ith th hlo ffct (Figu.5.-) du to img tnsltion svs to mphsiz th poblm of intfcing to multipl img modlity fomts. It is cl tht univsl img communiction fomt (IE DICOM) is quimnt fo idscl implmnttion. Evn ith phntom th thn ptint, co-gisttion s non tivil.

33 .5.3 Intpoltion Chpt : Plud Th ANTHOP PET imgs smpld onto th TPS CT disply scn by bilin intpoltion. Invitbly, CT nd PET pixls do not xctly lin up, so th PET img hs to b smpld by ith nst nighbou o bilin intpoltion mthod. A nst nighbou ppoch ould poduc high contst, mo pixiltd img, but th TPS ldy usd bilin intpoltion hn mpping CT dt to pixls. Th bility to choos btn mthods of intpoltion in th disply of imgs is common ftu of ddictd NM visttions. Th nst nighbou intpoltion mphsizs pixl to pixl vition hich is most usful fo dtcting smll mtstss. Th bilin intpoltion ffctivly intoducs lo pss filt nd hs smoothing ffct on th img hich movs som of th nois, mking it btt suitd fo th cognition of lg stuctus tht gnlly quid in diothpy pctic. This subtl diffnc s invibly mkd upon by NM physicins tht vid th imgs on th TPS scn, but my not b immditly ppnt to thos tht outinly vi th bilin intpoltion usd in diothpy imgs. Figus.5.3-,.5.3- nd psnt n ttmpt to xplin in visul tms th qulittiv diffnc in th img psnttions und th to diffnt intpoltion systms. Th subjct psntd is CT scn of smll high z componnt in cvity. This is CT scn nu of PET scn nod, chosn in plc of PET scn bcus it ill b mo fmili to ds ith diothpy bckgound. Figu.5.3- is linkd ith tbl.5.3- to sho tht th clocking ov of th gyscl ith th disply of PET imgs, th thn bing n tfct ssocitd spcificlly ith PET imgs, is n intinsic function of th TPS disply tht vlus of 3 o mo lys displyd s blck, on CT scns s ll s PET scns. Fig Imgs tkn fom th TPS oksttion. On th ight is th unzoomd TPS CT xil img of tissu quivlnt block ith smll high tomic numb substnc in th cntl cvity. On th lft is zoomd TPS vi of th cvity shoing th bilin intpoltion giving smooth img nd th clocking ov of th gyscl to blck. In th cnt is n img fom disply systm oth thn TPS using th nst nighbou img of th sm slic. It looks simil to th TPS img t this scl, but xhibits diffncs hn zoomd s shon in Figu Fig This is zoom of th cvity in Figu.5.3- und nst nighbou intpoltion. Th pixltd ntu of th img is diffnt fom th smooth img on th lft of Figu.5.3- tht sults fom th bilin intpoltion. Th gyscl is not povidd by th TPS, nd so dos not clock ov, so th is no cntl blck gion.

34 Chpt : Plud Fig A clos up on th cntl cvity. Th individul CAT pixls cntd on th vtics of th gid. Not tht th CT vlu tool on th TPS vgs th CT vlu of th cntl pixl ith tht of th ight nst nighbou pixls, but th bilin gyscl disply is bsd upon intpoltion btn individul pixls. Th individul pixl vlus tbultd in tbl sho 5 pixls bov 3, nd th clocking ov of th gyscl in th immdit vicinity of th cosponding vtics cn clly b sn. Th gid in this figu s dn using th TPS contouing tool. Th TPS stos contou points s odd pis of intg pixl coodints, so th points, hich th intsctions of th gid lins, loctd in th cnt of ch pixl. Th lins of th gid do not dfin th dgs of th pixls. gdlss of zoom fcto, CADPLAN ill not llo spcifiction of points in btn pixls. Th nunc of intpoltd img psnttion in functionl s opposd to ntomicl img cusd som xsption mongst clinicl stff, ho initilly unbl to concil th guidnc thy hd bn givn by NM stff fo intpting th img s displyd in th NM dptmnt ith th img s displyd on th TPS. This s univslly mnifst in th clinicin quying s to hth th hd bn co-gisttion o Tbl.5.3- Tbl of individul pixl vlus t gid vtics in Figu Thos vlus gt thn 3 in bold. This tbl is 7 clls id nd 8 clls high, hs th gid in Figu is 6 clls id nd 7 clls high bcus th clls in tbl.5.3- cospond to th gid vtics in Figu

35 Chpt : Plud.5.4 Mdicl Img Fomts Th PET imgs obtind indictly fom th PET cm vi digitl img nd nlysis suit (Digitl Jckt, DsAcc Inc, Chicgo, IL, USA). Th digitl suit PET fils DICOM pt complint. Th tgs of th dt lmnts usd fo co-gisttion givn in tbl Th CT imgs ldy psnt on th systm in CAT fomt. Although both fomts suppot ptint nm nd ptint idntifiction (ID), th to must b compd by us inspction bcus th usg is diffnt. Fo xmpl th ptint s fist nd lst nm is stmpd in tht od on th CT fils, but th od is customily vsd by th PET cnt optos. Th spcifictions of co-odints, dimnsions nd ointtions lso diffnt in th to potocols, but it is possibl to utomt th tnsltion nd tk into ccount ll ths pmts. In pctic som ssumptions gding ointtions md tht lid on th imging potocols, fo xmpl it s knon tht ll imgs to b tkn ith th ptint ft fist supin. Both fomts codd th z position of ch slic in intg mm, so ll co-gisttion could only b chivd to th nst mm. Th limiting fcto on th ccucy of th co-gisttion s th sptil solution of th PET dt, hos voxls 4 mm in ll 3 dimnsions. Th fiducils mtchd to dtmin th quid tnsltion. Th xtnl contou nd th outlin of th lft nd ight lungs thn mkd fom th CT imgs in th TPS. Thn th xtnl pogm s usd to sp in th PET tnsmission scn ith th sm tnsltion pmts s th PET mission scn. Th xtnl contou nd th outlin of th lungs could lso b discnd on th PET tnsmission scn, nd th ovly of th CT dtmind contous on this img dt s th min chck of th lignmnt of th dt sts. A supplmnty chck s th position of th fiducils on th PET mission scn ltiv to th xtnl contou fom th CT scn. On th bsis of ths compisons chngs to th dfind volums fom CT not md unlss th discpncy btn CT nd PET dt s gt thn 4 mm. CAT VAIABLE NAME DATA FILTYP Fil idntifiction numb, vlu 6 OIENT Slic Ointtion PATNAM Ptint Nm PATID Ptint ID ZPOS ltiv Z Position of th Slic in mm XPXSZE Th physicl x pixl siz in μm YPXSZE Th physicl y pixl siz in μm Divd fom CAT Filnm Slic Numb Tbl.5.4- CAT dt lmnts of us fo co-gisttion..5.5 Applying th mthod in clinicl pctic Th fist co-gistd ptint imgs obtind fo clinicl pupos not oiginlly nticiptd. A non-dicl cs s co-gistd ith th im of clssifying mtsttic diss in th nck. In ccodnc ith stndd imging potocols, th ptint s scnnd fom chin to mid bdomn on both CT nd PET, so it s possibl to vi th pimy s ll s co-gistd imgs. Th only vition s th plcmnt of n 8FDG lodd cicul 3

36 Chpt : Plud fiducil duing th PET scn on th Antio Midlin cm infio to stnl notch (SN) (S Figu.5.5-3). Although th co-gistd dt offd littl insight into th ntu of th glucos ctivity in th nck, du to th unlibility of co-gisttion in th nck ltiv to th chst, vi of th co-gistd CT nd PET dt sts povidd much usful insight into th clinicl implmnttion of co-gistd PET nd CT dt. CT nd cogistd PET imgs fo this ptint shon in Figus.5.5-,.5.5-, nd Obsvtions fom th fist ptint xpinc bodly s follos.. Th fiducils did not disupt th intpttion of th PET mission img. (S Figus.5.5-,.5.5-, nd.5.5-3). Co-gisttion outsid th thox gion smd to b lss libl. Th ppd to b som tisting of th toso t th lvl of th diphgm, nd in th nck gion th co-gisttion could not b lid upon to b ccut. 3. 8FDG signl in th vicinity of th spin on th PET scn s sn to mtch both obvious (S Figu.5.5-) nd somtims bly pcptibl (S Figu.5.5-) dmg to th vtbl column on th CT dt. 4. Th s som 8FDG ctivity ssocitd ith plul ffusion (s Figu.5.5-) in ddition to th usul physioicl 8FDG ctivity blo th lvl of th diphgm. 5. Quit spition t CT nd PET did not sm to b poblm fo imging o co-gisttion in th thox, xcpt t th lvl of th diphgm. 6. Th co-gisttion s sufficintly ccut to povid usful infomtion tht could not b discnd fom vi of th to dt sts sptly. 7. Dignosis, s opposd to dmction of tgt volums, is bst don on ddictd imging soft. A numb of dficincis in th diothpy disply md it difficult to distinguish n bckgound signl fom mot nodl involvmnt. 8. Inspction of th PET dt shod tht th Goss Tumou Volum (GTV) dn fom CT dt ould hv bn modifid if th cogistd PET dt hd bn vilbl (S Figu.5.5-3b) but bcus this pticul ttmnt involvd pllitiv postio to ntio nd ntio to postio (PA-AP) opposd pi ttmnt, no chng to th ttmnt pln s quid. Fig PET dt cosponding to slic lvl 8. cm () nd CT dt t slic lvl 8. cm (b). Th coincidnc of mtbolic ctivity in th PET scn ith th igulity of th bony stuctu of th vtbl column in th CT dt cn b clly sn. Not lso th ppoximt coincidnc of th GTV mkd fom th CT 4

37 Chpt : Plud dt ith th mtbolic ctivity on th cosponding PET scn. Th comptiv lck of physioicl 8FDG signl fom th lungs is lso ll dmonsttd. Figu.5.5- nd.5.5-b gin dmonstt th cpbility of PET to sho spinl involvmnt. At th tim of th vi of this img, th dition oncoist, lthough of mtstsis t slic lvl 8. cm, hd only bifly vid th CT dt, nd s not yt tht th s disct mtstsis t this lvl. Figu nd.5.5-3b sho tht th PET nd CT tgt shps diffnt. Fig PET dt cosponding to slic lvl 5. cm () nd CT dt t slic lvl 5. cm (b). Th mkd 4 postio to th lft lung suoundd by th thick lin shos glucos signl hich is blivd to hv bn du to plul ffusion (fluid in th plul spc). Fig PET dt cosponding to slic lvl. cm () nd CT dt t slic lvl. cm (b). Not th dk in th cnt of th ntio midlin PET fiducil is du to th gyscl clocking ov t vlu of 3. Th GTV mkd fom th CT scn is indictd by th thick solid lin. Whn th GTV is supimposd ov th co-gistd PET dt, it cn b sn tht th pttn of glucos uptk suggsts diffnt shp tht is ptilly coincidnt ith th CT divd GTV. Th ppnt spinl involvmnt in Figu.5.5- s lt confimd. This is n xmpl of th syngy of functionl nd ntomicl imging. vi of th ntomicl imging lon by qulifid clinicl stff hd not (initilly t lst) dtctd th spinl involvmnt, nd lthough th incsd glucos uptk s visibl on th PET img, its significnc might not hv bn lizd. Th combintion of th to imgs is thus supio to th 5

38 Chpt : Plud spt vi of both, s th incsd glucos uptk nd its significnc both obvious hn viing cogistd functionl nd ntomicl imgs..5.6 Fiducil Alignmnt Systm Th positioning on th CT nd PET couch poducd by th us of psonlisd polyuthn fom suppot (Figu nd Figu.5.6-5). Th suppot s lockd to th ttmnt couch ith ffilock, PMCI in hous lock fit solution. Th siz of th fom suppot s limitd so tht it ould fit though th bo of th PET cm. Th ms lso suppotd bov th hd to gt though th PET cm bo. Th CT scn hd th fiducils filld ith t, but to nbl thm to b imgd on th PET scnn, th tubs filld ith t contining ppoximtly micocui of F-8 FDG nd solidifid ith glling gnt, (Alcosob G5, Cib Spcility Chmicls, Thomston, Vic., Austli). This poducd solid substnc ithin th tub, thby ducing th isk of lkg nd contmintion. It s dcidd to us systm of disct fiducils (S Figu.5.6-3). Th siz of th fiducils s compomis to nsu tht thy could b sn on th TPS CAT (56 x 56 pixls) CT scn hil tining sufficint ccucy of sptil gisttion. PET fiducils plcd on th ntio midlin t SN nd t nd cm infio to SN on midlin. Th fiducil on th ntio midlin t cm infio to SN s plcd ith its long xis in th ltl diction to fcilitt dtmintion of th Z shift. Th fiducil on SN nd cm infio to SN plcd ith thi long xis in th supio-infio diction to povid dtmintion of th ltl shift. Disct fiducils lso plcd ltlly, on th hlf ntio postio (AP) lin, t nd cm infio to SN. Th ltl fiducils hd thi long xis lignd in th supio infio diction to fcilitt th dtmintion of th AP shift. Th fiducils lodd ith ppoximtly 37 kbq p mk, s compd to th ptint dos of MBq of 8FDG, dos chosn to mk th fiducils visibl fo loclistion ithout disupting th infomtion contnt of th mission img. Figu.5.6- shos th plcmnt of th fiducils in constuctd sgittl slic on ptint. Whil to othogonl lin lss vilbl both ovhd nd fom th ptint ight sid, th s only on lin ls on th ptint lft sid t th PET cm, so tht th supio infio position of th lft ltl fiducils s lss ccut thn th ight ltl fiducils. Additionlly, djustmnt of ptint ms movd th position of ths fiducils in th sup inf diction, s sn in Figu Fotuntly th AP position s stbl gdlss, nd ths fiducils only usd fo dtmintion of th AP shift. Fig Disct fiducils visibl in constuctd sggitl slic on th TPS disply. Th img is divd fom cogistd xil PET mission slics using th stndd TPS contouing img constuction tool. Th img dt is fom on of th ptints in th til mntiond in th nxt sction. Th body outlin is divd fom th CT scn dt nd th mtch of th fiducils ith th ntio sufc is cl. 6

39 Chpt : Plud At th lvl of th diphgm som tisting of th toso bcoms possibl dspit th polyuthn cst, nd cn s tht th fiducils t this lvl do not both mtch th skin sufc. Sinc th fiducils hv bn mtchd lsh it is cl tht this cnnot b coctd fo ith simpl tnsltion, o vn ottion. Sinc both PET nd CT ithout gomtic distotion, intoducing n ffin ill pobbly intoduc distotion lsh in th img dt st. gisttion outsid th thox is not of significnc in this clinicl scnio, but it dos mphsiz th limits of ccucy tht is chivbl. Fig Ltl disct fiducils on constuctd coonl pln. Th img is divd fom co-gistd xil PET mission slics using th stndd TPS contouing img constuction tool. Th img dt is fom on of th ptints in th til mntiond in th nxt sction. It is cl to s tht th fiducils not t th sm lvl in th supioinfio diction. Also not tht on of th lo fiducils intuds ithin th xtnl contou divd fom th CT scn dt. At th lvl of th diphgm som flxion of th toso cn occu dspit th polyuthn cst, mking it impossibl to chiv vlid mtch ov th full img spc vn ith full tnsltion nd ottion tnsfomtion. Blo th lvl of th diphgm th noml physioicl 8FDG signl fom th bdomn is visibl. Fig On of th svn disct fiducils hich is plcd on th ptint nd filld ith t fo th CT scn, 8FDG fo th PET scn. Also t th lvl of th diphgm, distotion du to quit spition duing th PET scn is most ppnt (Figu.5.6-). Ay fom th diphgm, th co-gisttion s sn to b ccut to ithin 4 mm in th tnsvs pln, o on PET pixl. This is not supising sinc th quid tnsltion divd fom th pixl co-odints of fiducils in th PET imgs. In th supio infio diction th ccucy is slightly btt t just ov hlf th slic sption, o -3 mm. Compison ith th lin fiducil mthod usd in th phntom study (Figu.5.-) shos supio gisttion ith th disct fiducils on ptint xcpt t th lvl of th diphgm. Quit spition is ccomplishd lmost ntily by th movmnt of th diphgm so th supio z discimintion of th disct fiducil mthod is bst dmonsttd by th gmnt t th supio mgin of th lungs in th ptint dt (Figu.5.6-6), compd ith tht in th lin souc phntom study. 7

40 Chpt : Plud Fig Supio-ntio vi of th polyuthn fom suppot usd fo ptint positioning fo th PET nd CT scns. Fig Ltl vi of th polyuthn suppot usd fo ptint positioning fo th CT nd PET scns. Fig Coonl pln vi of th PET tnsmission img ith th lungs outlind fom th CT scn. Th z discimintion is supio ith th disct fiducil systm. A 4mm mgin hs bn dn ound th lung contous to dmonstt th scl of th discpncy. 4 mm s tkn s th limit blo hich discpncy btn PET nd CT s tkn to b poduct of misgisttion. In th vicinity of th diphgm th spition inducd. In ddition th TPS lgoithms fo dtmining coss sctions in coonl plns nd fo dding th dimnsionl mgins both fil to dl ith th complx cscnt shp of th xil lung coss sction t th lvl of th diphgm. Thus th jggd shp of th contous t th lvl of th diphgm in this coonl vi, nd th intusion of th clcultd xpndd volum bing into th lung volum fom hich it s clcultd t th lvl of th diphgm both tfcts of th TPS systm. Just s diothpy stff lckd fmiliity ith NM pctic, so too th NM stff hd difficulty undstnding th diothpy stff pctic of ligning to th lss. Thy ould oftn, fo xmpl, djust th ptint s ms in th ovhd pos fo comfot immditly bfo img cquisition commncmnt, thus potntilly invlidting th lignmnt of th ptint nd th fiducils to th lss. Fo this son, dition thpist s initilly psnt fo 8

41 Chpt : Plud th img cquisition. Ultimtly syngy of pctic s chivd, ith high qulity imgs bing obtind ith n ccutly lignd ptint..5.7 Til On th bsis of ths sults, it s nxt dcidd to mbk upon til consisting of t lst ptints. Only thos ptints suitbl fo dicl ttmnt on th bsis of PET stging includd. Th som dcisions to b md gding imging potocols fo CT scns nd PET scns. Th PET scns fixd lys s 4 mm cubic voxls, slic thicknss 4 mm nd pixl siz 4 mm by 4 mm. Th slic spcings vilbl fo th CT scnn 3 mm, 5 mm nd mm. Stndd lung CT potocols hd pviously usd mm thick CT slics. Sinc bilin intpoltion s bing usd, mm CT slic sption mnt 4% of th PET slics ould b discdd. 3 mm CT slic sption s flt to involv too much contouing. 5 mm slic sption s doptd s compomis. On on occsion th tnsmission scn s not complt nd intpoltd slics hd to b usd. Fo n utomtd systm this could cus poblms. Th nds to b clos liison ith th PET cm optos to b bl to kno hn this sitution occus. Th sults of th til mo fully vid in sction.7, but Figu.5.7- givs n xmpl of singl slic fom til cs h it s possibl to duc th GTV. Fig PET ngtiv tumo xtnsion cn b xcludd fom dicl tgt volum. Shoing simultnous vi of CT nd cogistd PET dt fo th sm xil slic, cn s ho th lo PET signl in th ltl xtnsion of th mss (indictd s mkd on th CT scn by th thick dottd lin) in th lft cn b usd to xclud tht (th lin of xclusion dtmind fom th PET dt bing indictd by th thick solid lin) fom th GTV..5.8 Osophgl cnc In ddition to th til css, hv lso usd PET cogisttion fo n osophgl cs fo IMT ttmnt, s shon in Figu This s pcuso to til of osophgl ptints dlt ith in sction.7. 9

42 Chpt : Plud Fig Coonl pln constuction of co-gistd PET mission study of on osophgl cnc. Th thick outlin ound th osophgus is th pojction of th GTV mkd on th CT onto this pln. Th high intnsity PET signl in th lo pt of th osophgus cospondd ith sults fom visul inspction of th lumn, nd th GTV s subsquntly ducd fo ttmnt. This cs s not ctully pt of th til, but s fd bcus of conflicting infomtion bout th xtnt of th GTV fom visul inspction of th lumn nd CT. Th th imgs on th ight clos ups of th osophgus s thy ould pp to th clinicin hn ndd ith diffnt gyscls. It is dily ppnt tht th dtmintion of th xtnt of osophgl involvmnt is stongly coupld ith th thshold..5.9 Gyscl Disply An ly citicism of th systm s tht th poo solution (inbility to img nodl involvmnt) s du to using lin gyscl mp. Th TPS llos only lin stting of th gyscl indo (lthough it dos hv sophistictd non lin gyscl intpttion, this is only fo th ctiv indo, nd not fo th hol dt st). Any bity gyscl tnsfomtion hs to b md on th hol img st to void disupting clinicl intpttion, s th vition of PET intnsity fom slic to slic lso cis infomtion. A ng of non lin gyscl options s implmntd in CADPET, including simpl invsion, squ oot, ithmic, nd dptiv histogm qulistion 3. Ext contst s sn using th squ oot nd th dptiv histogm qulistion gyscl mps, hov th ithmic gyscl shod lg chng in contst sulting in th img bing unusbl. Thus it sms tht it is likly to b th siz of th img nd th bilin ppoximtion tht jointly duc

43 Chpt : Plud th contst of th PET mission img th thn th gyscl. Clinicl intpttion ould b idd by th us of nst nighbou mthod, nd th dmgnifiction of th img so tht ch PET pixl cospondd to on scn pixl (smllst possibl img siz). Th TPS ill not llo us to dmgnify. W hv noth vi (S Figu.5.3-) on th systm ittn pviously fo stotctic locliztion ppliction hich cn us to disply th sm CAT fil ith nst nighbou ppoximtion nd ch PET mission pixl mppd to fou scn pixls (Th TPS mps ch CT pixl to 49 scn pixls). Using this pogm it s possibl to chiv supio solution..5. Cliniclly usful spcts of PET disply. To b bl to disply co-gistd PET scns it is usful tht diothpy ttmnt plnning systm b bl to: Toggl btn nst nighbou nd bilin intpoltion. Shink th PET img until it is mppd pixl to pixl. Disply colou PET thshold img ov th CT scn fo simultnous inspction of both img sts. ott psnttion of th PET dt in th dimnsions. Allo dos to b supimposd ov th PET scn. An undstnding of th impotnc of ths spcts bsd on xpinc s vy usful in vluting commcil implmnttions tht subsquntly bcm vilbl..5. Clinicl Obsvtions Us of th initil vsion of CADPET s confind to us in th Physicl Scincs dptmnt und dict physics supvision. It s intndd to dvlop mo obust gnl us vsion, implmntd to nbl co-gisttion by plnns ithin 5 minuts. To chiv this it ould hv bn ncssy fo th xtnl pogm to utomticlly vy th supio infio tnsltionl shift to mximis th PET img ctivity ithin n outlin dn by th TPS us of th img of fiducil in th CT scn. To do this th pogm must b bl to d th coodints of th outlins tht stod in th hd of th CAT fils (As distinct fom th ctul img dt hich it cuntly sps in nd out.). Essntilly th TPS CT contou sttistic function tht clcults th mximum CT vlu ithin us mkd contou must b multd by CADPET. Although th pogmming tsk s ultimtly chivd, th initil motivtion lpsd hn th dptmnt quid its fist hybid imging dvic, PET-CT. Th cpbility s put to diffnt us, to fcilitt nlysis of phntom xpimnts on PET volum thsholds (s sction.8.). A cuing issu is th intnsity bov hich th 8FDG signl bcoms significnt. Although this is complx issu involving ltiv intnsitis nd noml physioicl signls, it ould b dsibl to dvlop gion spcific potocols fo th us of PET dt fo tgt dmction. This could involv input dt fom th dioists pot, such s, in th bsnc of ny nodl involvmnt, only s ith n intnsity of gt thn popotion of th mximum intnsity of th PET signl should b includd in th GTV.

44 .5. Tchnicl summy Chpt : Plud Th im of th til s to dtmin th popotion of css fo hich us of 3-D co-gistd PET dt ill modify th tgt volum, s msu of th utility of functionl imging fo tumou volum mking. This is th cntl topic of th nxt to sctions (.6 nd.7). Fom tchnicl point of vi it hs bn shon tht it is possibl to modify th TPS to disply co-gistd PET imgs in y hich is cliniclly usful fo dition Thpy Ttmnt plnning. It hs lso bn shon tht it is possibl to utiliz diothpy ptint immobilistion nd positioning xptis coupld ith simpl but dqut mthods of co-gisttion, to chiv diothpy tgt volum dmction ith th id of stuctul nd functionl imging. Th fficcy of ll fctiontd ttmnts dpnds on positioning ptints ccutly, nd s consqunc this skill is vy ll dvlopd in diothpy cnts. It cn b usd to gt dvntg in th sch fo mo ctin tgt volum mking using functionl imging. Long tm s this t s impovd by img guidnc tchniqus, impovmnts in gisttion of functionl imging to th isocnt bcm ncssy, hich is th min topic of chpt 4..6 Lung Cnc dicl diothpy (T) cn povid ppopitly slctd ptints ith unsctbl non-smll-cll lung cnc (NSCLC) ith polongd suvivl nd vn cu, 4,5 pticully hn givn ith pltinum-bsd chmothpy 6,7 o dlivd s continuous hypfctiontd ccltd T. 8 Filu to ccutly img ll goss diss nd to dfin n ppopit GTV uns th isk of unddosing gions of tumou hn T plnning is cid out. In som css, inccut imging cn vn cus complt gogphic miss of goss tumou subvolums. Ttmnt plnning bsd on suboptiml 3-D imging could incs th isk of loco-gionl lps nd ld to unncssy idition of uninvolvd noml tissu. In n hn highly confoml T is bcoming mo idly usd, ccut dlintion of goss tumou is ssntil. Modn diothputic ttmnt of NSCLC oftn uss no mgins ound goss tumou, typiclly ithout lctiv idition of cliniclly uninvolvd lymph nods. 9 Th 3-D T ttmnt plnning fo lung cnc hs long bn bsd on th us of ntomicl imging, spcificlly CT scnning. 3 Unfotuntly, publishd sugicl pots hv shon tht CT scnning is oftn inccut in stging NSCLC, pticully ith spct to lymph nod involvmnt, dlintion of tumou xtnsion into soft tissus nd dmction of th bod btn tumou nd tlcttic (collpsd lvoli) lung. 3,3 Thfo, ttmnt plnning bsd on CT lon, lthough until cntly th bst vilbl non-invsiv mthod, my not b good bsis on hich to mbk highly confoml T plnning. Stging ith PET, using FDG, is n impotnt dvnc in th imging of ptints ith NSCLC ho cndidts fo dicl T. Numous studis ith clinicl pthoicl coltion hv shon tht PET dlivs much mo ccut stimt of th tu xtnt of diss in NSCLC thn CT lon, pticully if CT nd PET usd togth in syngy. 33 PET is vlubl in slcting cndidts fo dicl T in to min ys. Fist, by fcilitting slction of ptints ithout goss systmic mtsttic diss nd ithout int-thocic diss too xtnsiv fo dicl T,

45 Chpt : Plud us of PET nsus tht only ptints most likly to bnfit fom ggssiv thpy ttd ggssivly. 34 Scond, bcus th xtnt of int-thocic diss is mo ccutly imgd, PET fcilitts T tgt dlintion nd should thby hlp minimiz th isks of gogphic miss of goss tumou nd void unncssy idition of noml tissus. 35,36 This is pticully in th cs of ptints ho not suitbl fo mdistinl nodl smpling. In pospctiv study of PET stging t PMCI, 3% of 53 conscutiv ptints dmd inligibl fo dicl T ft PET. PET dt usd to ssist ith ttmnt plnning fo th mining 7%. 5 Initilly, PET dt visully incopotd into th T ttmnt plnning pocss, using th bility of th dition oncoist to stimt th loction nd xtnt of PET-positiv stuctus on th ttmnt-plnning CT scn. Eith no ttmpt s md to co-gist PET nd CT dt o simpl -D co-gisttion s md bsd on ntomic lndmks. It s stimtd tht ppoximtly on-qut of ptints plnnd in this y quid significnt lttions to thi T filds to nsu dqut covg of PET-dtctd tumou. As sn in th pcding sction.5, 3-D co-gisttion soft s dvlopd tht nbld PET imgs to b impotd dictly into th T ttmnt plnning systm in us t th tim (CADPLAN, vsion 6, Vin Mdicl Systms, Plo Alto, USA) 37. PET imgs could b co-gistd ith ttmnt plnning CT imgs using fiducil mks. To tst th utility nd fsibility of this ppoch in clinicl pctic, pilot study s commncd. In this sction th mthods of img cquisition, co-gisttion nd ttmnt plnning using co-gistd PET/CT imgs dscibd. Th ffcts of 3-D PET/CT bsd ttmnt plnning on tumou covg nd on noml tissu idition dscibd in cohot of conscutiv ptints ho undnt both convntionl nd PET/CT-bsd plnning s pt of this pospctiv study. This mthod mks full us of th 3-D cpbilitis of PET nd could potntilly povid T cnts ithout ccss to th ltst intgtd PET/CT scnns ith 3-D PET-ssistd T plnning..6. Elligibility citi All ptints hd NSCLC nd cndidts fo dicl T. To b ligibl fo PET scnning, ll ptints should hv undgon convntionl (non-pet) stging invstigtions including CT scnning of chst, bdomn nd bin nd dionuclid bon scnning, ithout vidnc of distnt mtstsis o intthocic diss too xtnsiv fo dicl T. Additionlly, to b ligibl fo th plnning pt of th study, ptints quid to hv no vidnc of distnt mtsttic diss on thi PET scns nd to hv PET-dtctd intthocic diss tht could potntilly b sfly ncompssd in dicl T plnning tgt volum (PTV). Ptints ith Estn Cooptiv Oncoy Goup (ECOG) pfomnc sttus o ith ight loss gt thn % of body mss inligibl fo th study..6. Acquisition of PET nd CT dt fo ttmnt plnning. Ptints immobiliztion is s dscibd in sction.5.6. Th sm immobiliztion pptus s usd fo CT scnning, PET scnning nd ttmnt dlivy. Ptints st up fo imging o ttmnt, lying on flt igid bd tops, using lss instlld in th CT nd PET simulto nd ttmnt ooms. Ptints instuctd to xcis gntl bthing thoughout th scnning pocss. Fiducil mks usd s dscibd in sction.5.6 to 3

46 Chpt : Plud fcilitt img cogisttion. Tttoos plcd t th fnc points. Ptints scnnd on CT scnn, nd.5-cm xil imgs obtind to includ th nti lung volum. Ptints undnt fluooscopy on th simulto to cod tumou movmnt ith spition, nd othogonl simulto films tkn to nbl pot film compison duing ttmnt. All PET scns compltd ithin 48 h of th plnning CT scns using th stndd clinicl lung cquisition potocol. Ptints skd to fst fo mo thn 6 h bfo th scn. Th scns cquid on ddictd PET scnn (Gnl Elctic (GE) Qust 3-H, UGM Mdicl Systms, Phildlphi, PA, USA) t lst h ft i.v. injction of 5 MBq of F-8 FDG. dition thpists positiond th ptint in th PET suit in th sm mnn s fo th plnning CT scn using customizd flt pltt bd inst. Fiducil mks usd s dtild in sction.5.6. Th s scnnd includd th lo nck, chst nd bdomn to th lvl of th plvis, nd dt cquid ov 4 min. Acquisition includd tnsmission scn using singl-photon Cs-37 souc. Aft constuction of both ttnution-coctd mission nd tnsmission dt into 4.-mm tnsxil slics, th scns tnsfd to th TPS in DICOM fomt s dscibd in sction.5.4. An xmpl of PET scn shoing fiducil mks is shon in Figu.6.-. Fig..6.- PET img vid in th TPS, illustting fiducil mks on th ntio, ight nd lft chst ll. Th chst ll (), lungs ( nd 3), spinl cod (4) nd vtbl body (5) hv bn contoud on th cosponding co-gistd CT slic nd pojctd ov th PET img. Th CT GTV (7) is shon cosponding to this slic (solid d) nd th slic supioly (cossd d), dmonstting mdil xtnsion to ncompss tlcttic lung. No mgin s pplid to th CT GTV h it buttd th chst ll o vtbl body. Th PET/CT GTV (8) is shon cosponding to this slic (solid tn) nd th slic supioly (cossd tn). An of lss-intns FDG uptk s obsvd djcnt to th pimy tumou in tlcttic lung, quiing xtnsion of th PET/CT PTV to cov it on th slic supioly..6.3 PET nd CT img cogisttion. Co-gisttion s chivd by mtching th plnning CT fiducils ith th PET mission scn fiducils, using n x, y, z shift, nd this s vifid by comping lung contous fom th plnning CT scn nd th PET tnsmission dt s pviously dscibd in sction.5.6. Th TPS vsion in us in ou dptmnt did not suppot th us of co-gistd PET/CT imgs fo ttmnt plnning, ncssitting th dvlopmnt of th CADPET soft. Qulity contol fo th pocss of co-gisttion s initilly invstigtd using n ANTHOP s dscibd in sction.5.. Th mthod s found to b ccut to ithin 4 mm nd thfo suitbl fo us in T plnning fo lung cnc. It s considd tht this lvl of ccucy could not b significntly impovd ith th quipmnt vilbl bcus of th intinsic sptil solution of th PET dt, ith voxls of 4 mm in ll dimnsions. 4

47 .6.4 Contouing of GTV using CT lon nd CT plus PET Chpt : Plud Onc imgs co-gistd, th dition oncoist, fist in ssocition ith dignostic dioist nd subsquntly ith NM physicin, contoud to spt goss pimy tumou volums fo ch ptint, on using CT infomtion lon (GTV-CT) nd th oth using co-gistd CT nd PET dt (GTV-PET/CT). Ths GTVs thn tnsfd to plnning CT imgs on th TPS. Lymph nod volums considd positiv fo tumou by th dioist mkd sptly t diffnt sttions nd dsigntd GTV-CT, GTV-CT tc. Th folloing uls follod fo GTV contouing ith CT lon: All s of goss pimy lung tumou contoud, using lung indo sttings fo th intfc btn tumou nd lung nd using mdistinl indo sttings fo th intfc btn tumou nd mdistinum. All mdistinl o hil lymph nods ith shot xis < cm contoud. 3 If cl sption could b distinguishd btn tumou nd tlcttic lung, only visibl tumou s contoud. If th s no sption ppnt, th nti volum of tlcttic lung s contoud. cnt contstnhncd CT scns usd to hlp in this sitution. Th dition oncoist, in consulttion ith NM physicin, thn mkd th FDG-vid tumou on th lvnt sis of PET imgs. Tnsvs CT nd PET slics displyd sid by sid s ch CT slic s mkd ith th GTV contou. Th GTV dt points simultnously displyd on th PET img s thy mkd nd ditd until th dition oncoist s stisfid tht th contou s s ccut s possibl. Th folloing uls follod fo contouing GTV ith PET/CT: All s of goss FDG-vid lung tumou contoud, using lung indo sttings fo th intfc btn tumou nd lung nd using mdistinl indo sttings fo th intfc btn tumou nd mdistinum. Th supio solution of CT s usd in dfining th tumou lung intfc. If PET shod tumou xtnsion into th chst ll o mdistinum tht s not ppnt on CT, this s includd ithin th GTV. If pt of th cicumfnc of tumou s FDG ngtiv, commonly bcus of ncosis, th nti tumou cicumfnc s still includd ithin th GTV. All FDG-vid mdistinl o hil lymph nods contoud gdlss of thi dimnsions if thy considd by th NM physicin to contin tumou. Bcus of ptil volum ffcts, nods > cm ith significnt FDG uptk considd positiv, vn if msud stnddizd uptk vlu (SUV) s <.5. 3 If cl sption could b distinguishd btn tumou nd tlcttic lung hn PET nd CT imgs co-gistd, FDG-vid tumou s contoud vn if th s no ppnt sption ppnt on CT lon. Hov, if th nti volum of tlcttic lung s stongly FDG positiv, it s includd ithin th GTV..6.5 Ction of th PTV nd ttmnt pln In ll css, th ttmnt psciption s 6 Gy in 3 fctions to th PTV dlivd in -Gy fctions ov 6 ks using confoml ngmnt of copln bms. Constints on noml tissus includd mximum spinl cod dos of 46 Gy nd mximum lung V (pcntg of th totl lung volum civing Gy o mo) of lss thn 35%. Th PTV s ctd by th dition oncoist by pplying 3-D.5-cm mgin to th GTV. This mgin 5

48 Chpt : Plud s ducd o omittd in gions h th tumou buttd fixd ntomicl boundy (.g. vtbl body o postio chst ll ithout invsion). If th pimy tumou nd nodl volums idly sptd, thy connctd by contouing intvning lymphtic gions (.g. if lft lo lob tumou nd ight ptchl nods th only sits of involvmnt, th intvning subcinl gion s contoud to connct th to gions of goss tumou). Ech CT-divd PTV s incsd to llo fo spitoy movmnt msud on fluooscopy of th tumou t th tim of simultion. This s unncssy fo PET/CT plns bcus th PET img s cquid ov mny spitoy cycls. To spt PTVs contoud fo ch ptint. Th fist using th GTV-CT nd th scond using th GTV-PET/CT. A dition thpist thn ppd to spt ttmnt plns fo ch ptint, bsd on ch of th PTVs. Dosimty fo ll ptints s cid out by singl dition thpist. Idnticl guidlins follod ith spct to ttmnt psciptions nd bm ngmnts. In ch cs, 6-MV photons usd nd tissu inhomognity coctions ccountd fo. Whn quid, bm modifiction dvics usd to optimiz dosimty. ICU guidlins follod hn ssssing dos to th tgt nd suounding noml tissus. In css h th poximity of spinl cod plcd stictions on dos homognity to th tgt, th dition thpist nd oncoist collbotd to chiv n ccptbl outcom. Ttmnt s dlivd using th PET/CT pln s it s considd most likly to b ccut..6.6 Compison of CT lon nd PET/CT divd ttmnt plns Fo th puposs of compison of th CT-lon nd PET/CT divd ttmnt plns, th tgt volum divd fom th ltt s considd to b th gold stndd o th tu PTV. Dvitions fom this pln in th CT-lon pln thfo considd to b os. This s justifid on th bsis tht ll publishd studis sho PET/CT stging to b much mo ccut thn CT stging lon, lthough it s cognizd tht no imging study cn giv pfctly ccut sults nd tht th only tu gold stndd in this cs ould b utopsy. Diffncs in tumou covg nd volums of lung includd in th ttmnt plns nlysd using simpl dsciptiv sttistics. Th V hs bn potd s cliniclly lvnt indicto of idition of noml lung..6.7 sults Th pocdus fo CT nd PET co-gisttion nd ttmnt plnning dscibd sctions dily implmntd in clinicl pctic duing th study. Hov, th mthod did significntly incs th tim tkn to pln ch ptint nd quid dditionl tim commitmnts fom th dition oncoist, imging physicin nd dition thpists. Appoximtly 4 h of dditionl plnning tim s quid p ptint. Aft cuitmnt of th fist f ptints, th tm bcm mo confidnt nd th pocss s mo fficint. It is likly tht th nd fo dditionl plnning tim could b futh ducd ith mo xpinc nd mo utomtd soft..6.8 Ptint chctistics Dtils of th post-pet clinicl stgs fo th ptints in th study givn in Tbl.6.-, togth ith dtils of th loction of th pimy tumou, th psnc of tlctsis nd th influnc of PET on ttmnt plnning. To ptints, A nd B, hd undgon pio sctions fo NSCLC nd civing dicl T fo cunt diss. Most ptints in this study hd stg III diss, nd in six css (6%), th s significnt tlctsis ssocitd ith th pimy tumou. 6

49 .6.9 Effct of PET on th covg of th pimy tumou. Chpt : Plud In fiv ptints (E, F, G, H nd I), significnt s of lung collps nd/o consolidtion psnt tht contiguous ith th pimy tumou. In ch cs, it s possibl to distinguish n of high FDG uptk on th PET scn, psumd to b tumou, fom s of lo uptk in consolidtd lung, psumd to b f fom tumou. Ths boundis btn tlcttic lung nd tumou could not b distinguishd using CT lon. Th thfo significnt vitions in shp nd volums btn th GTV on th CT nd PET/CT plns. In fou ptints ith tlctsis, ttmnt plns bsd on CT lon significntly ovstimtd th GTV nd consquntly th PTV..6. Effct of PET on covg of involvd lymph nods. P- nd post-pet stg goup lloctions th sm fo ll ptints xcpt on; PET scnning fo ptint D sultd in upstging fom stg N IIIA to N3 IIIB. Dspit th simility in stg goupings, th xtnt of lymph nod diss imgd by PET nd PET in combintion s oftn significntly diffnt fom tht obsvd on CT lon. In th css (C, D nd J), tumou s idntifid on CT/PET imgs t lymph nod sttions tht ppd noml on CT imgs. Dspit idntifiction of dditionl tumou on PET, th siz of th PTV mind simil in ptints C nd D. In cs C, disct hil nod involvmnt s dtctd on PET, hs on CT, th nods indistinguishbl fom th pimy tumou. This ltd th shp of th PTV. Although th nti goss tumou mss s still includd ithin th high-dos volum on th CT pln, significnt pt of th PET/CT PTV s missd on th CT-lon pln. This hd th ffct of ducing th iditd mgins ound th goss tumou. Although th PET/CT PTV s lg, th bm ngmnt usd covd simil volums of noml tissus nd, thfo, no significnt chngs in dos to lung occud. In ptint D, in ddition to th bnoml ipsiltl hil nods ppnt on th CT scn, noplstic subcinl nd contltl mdistinl nods dtctd on th PET scn. A fou-fild pln s usd to cov both PTVs, but th fild dimnsions nd gnty ngls quit diffnt, bing significntly lg to cov th xtnt of diss notd on PET scn. Although th subcinl mss ould hv bn ttd dqutly on th CT pln, th contltl nodl diss ould hv bn outsid th CT/PTV. 7

50 Chpt : Plud Ptint Stg Sit of pimy o Influnc of PET on Minimum PTV b Atlctsis /consolidtion cunt tumou T pln dos ith CT-only pln A cunc Mdistinum Dcsd lung V 39 Gy Nod B cunc ML nd mdistinum Littl chng 4.6 Gy Mino infctiv consolidtion C T N LLL Btt PTV mginl 53 Gy Nod covg D T N3 LUL Avoidd gogphic.8 Gy Nod miss E T4 N UL/ML Avoidd gogphic 3.4 Gy ML nd ML collps miss, dcsd lung V F T4 N3 LUL Dcsd lung V 36 Gy Mino infctiv consolidtion G T4 N LUL Avoidd gogphic 9.7 Gy LUL collps miss H T N LLL Littl chng 54.7 Gy LLL collps I T N LLL Btt PTV mginl 9.4 Gy LLL collps covg J T N ML Btt PTV mginl covg, dcsd lung V 3.5 Gy ML collps Tbl.6.- Ptint chctistics nd ovll ffct of PET on ttmnt pln. () indicts stg ft PET, (b) indicts PTV fd to in tbl is th tu o PET/CT PTV. LLL dnots lft lo lob, LUL dnots lft upp lob; ML dnots ight middl lob; UL dnots ight upp lob; V is th pcntg of th totl lung volum civing Gy o mo..6. Influnc of PET scnning on PTV. Th PTV divd fom CT scns lon ngd fom 3.5 to 34.3 cm 3 nd on vg not significntly diffnt fom thos plnnd using CT/PET imgs (p.3). Hov, this givs mislding impssion of th ffct of PET. In th css, th volum of PTV s mo thn % gt fo th PET-ssistd pln (vg incs in volum 4 cc) compd ith tht of th CT-lon pln. In six ptints, th PET/CT PTV s smll by % o mo (vg 88 cc). In on cs (ptint D), th bsolut volums lmost idnticl, but thy occupid significntly diffnt ntomic loctions (Figu..6.-). 8

51 Chpt : Plud Fig..6.- Bm s y vi pojction of PET/CT (d opn htchd) nd CT PTVs (blu solid colou) fo ptint D. Th PET/CT pln includd subcinl nd contltl mdistinl lymphdnopthy in th PTV tht s not ppnt on CT. PET, positon mission tomogphy; PTV, plnning tgt volum..6. isk of gogphic miss. In vy cs, pt of th PET/CT PTV (nging fom to 4%) s loctd outsid th CT PTV. In th css, gions of th CT/PET GTV loctd ntily outsid th CT PTV. This sitution s gdd s gogphic miss bcus gions of goss tumou, ppnt on PET/CT, ould not hv bn contind ithin th tgt volum hd ttmnt bn dlivd using th CT-divd pln..6.3 Minimum doss in th PTV Indqut dition dos givn to th tu PTV ( tgt volum tht contins ll goss tumou nd is most closly ppoximtd by th PET/CT pln) is likly to b ssocitd ith dcsd pobbility of tumou contol. In this study, hn PET/CT nd CT-lon ttmnt plns compd, th s sttisticlly significnt diffnc in th pcntg of th tu PTV tht civd, 57 Gy (P.5) nd th s lso diffnc in th minimum dos givn to th PTV (P.4). Th pcntg of CT/PET PTV tht s not includd ithin th CT PTV ngd fom to 6%. Accoding to ICU commndtions fo inhomognity ithin tgt volums, th minimum dos ithin PTV pscibd to 6 Gy should idlly b 57 Gy o mo. Th mn pcntg volum of th CT/PET-divd PTV tht civd dos lss thn 57 Gy hn this PTV s usd fo plnning s.%. In to css, th cold spots ithin th PTV of lss thn 5 Gy bcus of poximity of tumou to th spinl cod, lding to dlibt unddosing of pt of th PTV to min ithin ou sttd spinl cod dos constints. Hov, hn th CTlon PTV s usd fo plnning, th mn volum of th tu PTV (i.. th PET/CT PTV) tht ould hv civd lss thn 57 Gy s.3%, nd in ight of ptints, th ould hv bn cold spots tht civd lss 9

52 Chpt : Plud thn 5 Gy, pimily bcus of indqut covg of th tu PTV. In th css, mo thn % of th PET/CT PTV s not includd ith th CT-lon PTV, nd in to of ths, th figu s 4%. A dos volum histogm fom ptint ith indqut covg of th PET/CT PTV is shon in Figu Fig Ptint E. Cumultiv dos volum histogms shoing covg of PET/CT PTV by PET/CTdivd ttmnt pln (d) nd CTlon-divd ttmnt pln (blu). Assuming tht PET/CT ccutly imgd th tumou, th pln ppd using CT lon is clly infio to th PET/CT..6.4 Effct on dos to noml lung. Mdin lung dos nd V not significntly diffnt in CT plns compd ith tht in PET/CT plns (p.8 nd p.86, spctivly), gin flcting th fct tht PTV could b incsd o dcsd ft PET nd tht ths chngs tndd to cncl out on noth hn n vg s clcultd. Hov, in to css, both of hich hd tlctsis, dqut covg of th CT PTV could only b chivd if lung V of >35% s ccptd. Whn th PET/CT PTV s usd fo plnning, th V s lss thn 35% in ll css..6.5 Inspition Sctions.6.-4 dscibd in dtil pcticl mthod fo th incopotion of PET/CT dt into idly usd TPS. Povidd th ptint cn b st up ith fiducil mks in n idnticl position on th PET scnn nd th plnning CT scnn nd PET imgs cn b xpotd to th T plnning pogmm, th mthod could b potntilly hv bn usd in ny ppopitly quippd T cnt, but in th vnt th subsqunt vilbility of commcil systms (PET-CT nd TPS) dsignd fo this pupos md such ffots un-ncssy. In th pilot study of th tchniqu in clinicl pctic, it s found tht th mthod okd ll, lthough it did qui dditionl soucs to implmnt nd ndd significnt tim commitmnt by dition oncoists, imging spcilists nd dition thpists, s ll s th Mdicl Physics xptis fo th dvlopmnt of th study. As mntiond in sction.5. CADPET s nv dvlopd nough to b obust nough to b commndd fo us unsupvisd. Th goups okd closly togth s tm to implmnt th tchniqu. 3

53 Chpt : Plud Fo ll th ptints in th study, th chngs to th PTV s sult of th mthod. Ths somtims subtl, oftn ffcting only th mgins pplid ound th goss tumou nd in th mjoity of css pobbly ould hv hd no significnt ffct on th pobbility of locl contol. Hov, in th css (3%), th highly significnt chngs to th PTV, ithout hich som gions of PET-dtctbl goss tumou ould hv bn loctd outsid th PTV hd th CT-lon pln bn usd to dliv thpy. In ths css, th pobbility of ttining locl contol could potntilly b vy much ducd by filu to incopot PET into th ttmnt plnning pocss. Th us of PET did not hv consistnt ffct on oth pmts such s th siz of th PTV o th V, lthough in lg study, significnt ffcts might bcom ppnt. Th s tndncy fo th V to bcom smll in css ith xtnsiv tlctsis hn PET s usd to dtmin th boundy btn tumou nd consolidtd lung. Th s n unusully high popotion of ptints in th study ith tlctsis, hich could flct som indvtnt slction bis in cuitmnt. Th mo ligibl ptints duing th til piod thn th vilbl plcs in th study. It hs bn potd tht PET-bsd scnning cn hv pticully poful ffct in ptints ith tlctsis. 38,39 Th study, lthough it contins ltivly smll numb of ptints, is consistnt ith oth publishd studis of PET ssistd plnning in NSCLC. 4,4 In ll studis, PET hs hd significnt influnc on th stimt of th GTV in substntil popotion of ptints nd in thos css hs influncd th dsign of th PTV nd consquntly th dsign of th T ttmnt pln. Typiclly, on-thid o mo of ptints hv significnt chngs to thi ttmnt plns, ith to nsu dqut tumou covg o to duc unncssy idition of noml tissus. Th is contovsy ov th bst y to us PET to dfin th GTV nd ho to us PET to tk ccount of tumou movmnt. Th idl gol is th syngy of PET nd CT to tk dvntg of th bnfits of ch; tht is, PET cn oftn tll th ntu of lsion (noplstic o not) nd lthough CT my b cpbl of dfining its dg mo ccutly, movmnt of lsions duing spition is mo dqutly cptud by th tmpolly intgtd infomtion in th FDG-PET imgs. Exclusiv us of SUV thsholds (bsolut thsholds of pixl vlu s opposd to ltiv tios) to dfin tumou dgs s considd unlikly to b usful bcus of th vibility of this pmt in tumous nd inflmmtoy pocsss nd bcus of ptil volum ffcts. 4 Th mthod dscibd in this study hs bn supsdd du to th dvnt of PET/CT hybid scnns. Nvthlss, th findings ith spct to th chngs in ttmnt plns ith combind PET/CT min unffctd, nd simil sults should b obtind ith co-gistd imgs fom spt CT nd PET scnns o fusd imgs fom combind scnn, povidd th ptint positioning is poducibl. In sction.7 ill vi som clinicl ok tht s motivtd by xpinc ith stndlon PET imgs, but xcutd ith PET/CT scnn. Ths sults tmndous motivtion to pusu th syngy of diothpy nd functionl imging. Pomising n combind mthod ppochs nd pid tchnicl dvncs in T dlivy hld th pomis of dos scltion to th tumou hil psving noml tissu toxicitis t ccptbl lvls. In lung cnc, dos scltion using highly confoml T, fcilittd by mthods such s intnsity-modultd T, s likly to b futil if ttmnt plnning s not bsd on n ccut stimtion of th tu goss tumou xtnt. 43 It s cl tht PET cn impov ccucy of lung cnc imging, nd it should b considd complmnty tchnoy to ths n 3

54 Chpt : Plud ttmnt dlivy mthods. With btt ptint slction, mo ccut imging nd supio ttmnt dlivy, significnt futh pogss tods impoving locl contol of unsctbl lung cnc ith T might b md..7 Osophgl cnc Th mjoity of ptints ith loclly dvncd osophgl cnc mngd pimily ith chmodition. Hov, th pognosis fo such ptints is poo ith publishd fiv-y suvivl ts of ound % 44,45,46. Fo diothpy ttmnt plnning, CT psnts th stndd mthod fo tumou volum dlintion, dspit som inhnt limittions 47. Fo osophgl cnc, CT is not lys ccut, pticully hn dfining th cnil nd cudl xtnt of th pimy tumou in th osophgus. Mthods to incs th ccucy of tumou volum dlintion hv th potntil to impov locl tumou contol. As intoducd in sction.4. PET using FDG is functionl imging modlity tht povids physioic infomtion bsd on ltd tissu mtbolism. Th ol nd potntil vlu of PET scnning in ctin tumous, including osophgl cnc, hs bn idly invstigtd. Whn usd fo initil stging of osophgl cnc, PET is mo ccut thn CT fo dtcting lymph nod nd distnt mtstss, thby lloing mo ccut slction of th most ppopit ttmnt 48,49,5. PET hs high snsitivity nd spcificity fo diss ithin th osophgus ith snsitivity of 9 % 5. It lso dmonstts high snsitivity (3 77%) nd spcificity (86 99%) fo dignosis of pthoicl lymph nods thn dos CT (snsitivity 57%, spcificity 69 99%) 5,5,53,54,55,,56. Although, th pcis ol of PET in th mngmnt of osophgl cnc continus to volv, it is ppnt tht this imging modlity is bing utilizd ith incsing fquncy. Fo dition oncoy, th s mounting vidnc to suppot th nd fo this typ of functionl infomtion on tumous nd thi suoundings fo th pupos of diothpy ttmnt plnning 57,58. Svl potd studis hd shon tht th incopotion of FDG-PET into convntionl CT-bsd diothpy ttmnt plnning fo ptints ith lung cnc could sult in lttions to ptint mngmnt nd dlintion of tgt volums hn compd to CT lon 39,4,59,6,. Simil studis hd lso bn potd fo hd nd nck cnc nd lymphom 6,6,63. This pospctiv study s dsignd to vlut th impct of PET on CT-bsd diothpy ttmnt plnning fo ptints ith osophgl cnc using n intgtd PET/CT scnn. It is likly tht th incsing vilbility of this tchnoy ill ld to mo idspd us of PET/CT units fo diothpy ttmnt plnning. This study sought to dtmin ho th us of combind PET/CT ould lt th dlintion of tumou volums compd to CT lon if PET/CT is ssumd to mo ccutly psnt tu diss xtnt..7. Study Schm Th study schm is dpictd in Figu.7.- Eligibl ptints thos ith histoiclly povn squmous o dnoccinom of th osophgus stgs I III nd ECOG pfomnc sttus, h th ttmnt intnt s dicl chmodiothpy (dition dos 5 Gy) folloing compltion of ll non-pet stging invstigtions tht did not vl vidnc of mtsttic diss. As minimum quimnt, ll ptints quid to hv undgon osophgoscopy, CT scn of th chst nd bdomn, nd outin lbotoy blood tsts s pt of thi 3

55 Chpt : Plud non-pet stging invstigtions. Th study s ppovd by th PMCI Ethics Committ nd ll ptints gv ittn infomd consnt. Osophgl cnc Complt non-pet Elligibility - no mtsttic diss - dicl chmodition PET/CT scnning No mtstss GTV mking of hd copy CT Imgs by nucl dioist GTV contouing of CT dtst by dition oncoist GTV mking of hd copy PET/CT Imgs by nucl dioist GTV contouing of PET/CT dtst By dition oncoist Plnning bsd on CT dtst Plnning bsd on PET/CT dtst Pln compison Fig..7.- Flo digm outlining study schm..7. Ptint simultion nd cquisition of PET-CT dt sts. Ech ptint undnt combind PET/CT scn in th diothpy ttmnt position using n intgtd PET/CT scnn (Discovy LS, GE Mdicl Systms, Miluk, WI) tht svd s both dignostic nd diothpy plnning scn. Simultion s pfomd ccoding to stndd potocols fo osophgl cnc ptints civing 3D confoml T t PMCI. Th PET/CT scn incopotd th lo nck, thox, bdomn nd plvis in ll ptints. Ptints injctd ith btn 3 nd 4 MBq of FDG nd std lying on bd fo t lst h pio to scnning. A fou-slic hlicl mod CT scn s cquid duing quit spition ith pmts s quid fo outin PET ttnution coction nd co-gisttion. Ths 4 kvp nd 8 ma, 5. mm slics ith n intvl of 4.5 mm. Th tns-xil FOV s 5 cm fo both CT nd PET. Th minimum bo dimt fo 33

56 Chpt : Plud th PET/CT scnn s 6 cm. PET scnning s pfomd in D mod, in th cphlic to cudl diction, nd quid fiv o six bd positions t 5 min p stp. Dt s constuctd using n odd subst xpcttion mximistion lgoithm nd ttnution coction divd fom CT dt. Th PET, CT nd cogistd PET/CT imgs thn vid on oksttion (GE Entg, GE Mdicl Systms, Miluk, WI). All of th PET imgs vid by n xpincd PET physicin fo stging puposs. Ptints ith PET dtctd mtsttic diss cm off study ith no futh dt collction, hil ptints ho did not hv mtsttic diss on PET nd dmd suitbl fo dicl ttmnt pocdd to th diothpy plnning phs of th study. Th CT nd PET dt sts convtd to DICOM fomt nd tnsfd vi ntok link to th TPS (FOCUS, CMS lphtch, St Louis, MO) fo tumou volum dlintion nd ttmnt plnning..7.3 Dlintion of tgt volums nd ttmnt plnning Fo ch ptint, to spt GTVs dfind, on bsd on CT dt lon (GTV-CT) nd noth bsd on combind PET/CT dt (GTV-PET). dioist/pet physicins ho dully qulifid to d both CT nd PET imgs ould initilly mk th gions of goss tumou (pimy tumou nd involvd lymph nods) on hd copy plnning CT nd PET/CT scns ccoding to pdfind study guidlins. In n ffot to minimis bis, to spt dioist/pet physicins ssignd to mk th CT lon nd PET/CT dt sts fo th sm ptint in blindd fshion. Hd copis of dignostic CT scns nd bium sllo studis, s ll s osophgoscopy, bonchoscopy nd pthoy pots md vilbl to ch dioist/pet physicin hn mking th hd copy plnning CT nd PET/CT dt sts, nd ths tkn into ccount hn dfining th GTV. Fo th CT lon dt st, th pimy tumou in th osophgus s dfind s gions of bnoml osophgl ll thickning (including focl mul noduls o msss) s dtmind by n xpincd dioist ccoding to stblishd stndd potocols. In ddition, gions of tumou dscibd on osophgoscopy but not sn on CT lso includd in th GTV-CT. gionl lymph nods gt thn o qul to mm in mximl dimt considd tumou nd includd in th GTV. Fo th PET/CT dt st, gions of goss tumou dfind ccoding to pdfind consnsus guidlins stblishd by xpincd dition oncoists nd dioist/ PET physicins t PMCI. As of goss tumou dfind using th complmnty ftus of PET nd CT. Using this ppoch, visul intpttion of th PET img s usd to dtmin th ntu of lsion nd th CT img to dtmin its ntomicl boundy (.g. out ll of osophgus, o dil xtnt of pimy tumou). In css h no boundy s visibl on CT (.g. cnil o cudl xtnt of pimy tumou), th FDG vid tumou volum s dfind using qulittiv visul ssssmnt of th PET img tht s pplid ith igoous thsholding to noml tissus. Th PET imgs vlutd qulittivly on SUV-nomlizd gy scl fo th intnsity nd distibution of bnoml FDG uptk. FDG PET scns nomlisd using th liv s th fnc tissu, on th soning tht, pt fom th bin nd, vibly, th ht, hptic tissu hs th highst noml soft tissu uptk of FDG und fsting conditions. Using lin gy scl, th liv is st in th middl of th 56-lvl gy scl (mid-gy). Fo fusd PET/CT imgs inbo colou scl s usd fo th PET dt ith th liv st t th intfc btn blu nd gn. 34

57 Chpt : Plud Using ths guidlins th intnsity of tissus such s mdistinl blood pool, nd bon mo cn b poducibly compd to hptic ctivity nd th ltiv intnsity of tumou dposits cn lso b ppcitd btn studis. Tumou boundis usully dfind t th junction btn yllo nd ong on th inbo scl. Sinc compbl colou scls not cuntly vilbl on ou plnning systms, th colou scls mnully djustd to povid compbl dmction of tumou to tht outlind on th PET/CT imgs by th dioist/pet physicin. This mthod s considd by th clinicl stff to b mo ccut nd poducibl thn smiquntittiv mthods such s th us of SUV scls o FDG intnsity lvls, hich flt to b poblmtic 64. This poblm hs bn highlightd in study by Nstl t l. tht compd fou diffnt mthods fo dlintion of FDG-vid tumou volum in ptints undgoing diothpy plnning fo non-smll cll lung cnc 65. It s ssumd tht FDG vid gions colting ith possibl loction of tumou on CT tu positivs. Enlgd lymph nods on CT tht not FDG-vid includd if thought to b cliniclly suspicious. Folloing hd copy mking of th to dt sts fo ch ptint by spt dioist/pet physicins (CT lon dt st by fist dioist/pet physicin nd PET/CT dt st by scond dioist/pet physicin), th tting dition oncoist ould thn us ch hd copy img sptly to contou th GTV-CT nd GTV-PET on th ttmnt plnning comput (i.. GTV-CT copid fom hd copy CT dt st, nd GTV-PET copid fom hd copy PET/CT dt st). An ppopit clinicl tgt volum (CTV) s gntd fo ch GTV by pplying stndd mgins (5 mm dilly nd 4 cm longitudinlly), nd th PTV s thn gntd by pplying volumtic mm mgin. Spt, optimisd ttmnt plns poducd fo both th PTV-CT nd th PTV-PET in ccodnc ith ICU 5/6 commndtions. Ptints ttd ccoding to th PET/CT-bsd pln..7.4 Pln Compison Th to ttmnt plns fo ch ptint compd ith spct to th contoud GTV, PTV nd noml tissu stuctus. Pmts dscibing th GTV ssssd to dtmin if th s ny chng to th dlintion of ctiv tumou sulting fom th ddition of PET infomtion. Fo ch ptint, volumtic nlysis of GTV-CT nd GTV-PET s pfomd to quntify th popotion of PETvid diss tht s not includd in th GTV if CT dt lon usd fo diothpy plnning (shdd gion in Figu..7.4-). This pmt povids n stimt of th mgnitud of th diffnc in dtmining th GTV. Similly, volumtic nlysis of PTV-CT nd GTV-PET s pfomd to quntify th popotion of PET-vid diss tht s not includd in th PTV if CT dt lon usd fo diothpy plnning (shdd gion in Figu..7.4-b). This pmt dtmins hth o not gogphic miss of goss tumou ould hv occud if PET is ssumd to b th gold stndd. Fo th pupos of this study, indqut covg of th GTV-PET hs bn dfind s gd gogphic miss. Assssmnt of th cnil nd cudl xtnt of th pimy tumou GTV s dfind by CT lon vs PET/CT s lso compd. 35

58 Chpt : Plud Fig Compison of ttmnt plns. () Th popotion of PET-vid diss (GTV-PET) xcludd fom th CT-bsd GTV (GTV-CT) s quntifid fo ch ptint nd is psntd in this digm by th shdd gion. (b) Th popotion of PET-vid diss (GTV-PET) xcludd fom th CT-bsd PTV (PTV-CT) s quntifid fo ch ptint nd is psntd in this digm by th shdd gion. Incomplt covg of GTV-PET by PTV-CT s dfind s gd gogphic miss (gogphic miss of goss tumou). (c) Digm illustting ho CTbsd ttmnt pln (PTV-CT) my dqutly cov th GTV-PET but not th PTV-PET (shdd gion), thby potntilly sulting in gogphic miss of micoscopic tumou. Indqut covg of PTV-PET s dfind s gd gogphic miss. (d) DVH fo PTV-PET gntd fo th CT-bsd ttmnt pln. Covg of th PTV s considd to b dqut if t lst 95% of PTV-PET civd t lst 95% of th psciption dos. A lss vlu s scod s gd gogphic miss. Bcus of th gnous longitudinl mgins pplid to th GTV to gnt th PTV hn tting osophgl cnc, it is possibl tht ttmnt pln bsd on CT infomtion lon my dqutly cov th GTV-PET but not th PTV-PET (shdd gion in Figu..7.4-c). This could lso potntilly sult in gogphic miss of tumou though unddosing of gions contining micoscopic diss. Fo th pupos of this study, indqut covg of th PTV-PET hs bn dfind s gd gogphic miss. To ssss th dqucy of PTV covg, th mthod dscibd by Mh t l. in study of PET fo diothpy ttmnt plnning fo non-smll cll lung cnc s mployd 39. Dos-volum histogms (DVH) fo PTV-PET gntd fo th ttmnt pln bsd on CT infomtion lon (Figu..7.4-d). Covg of th PTV s considd to b dqut if t lst 95% of PTV-PET civd t lst 95% of th psciption dos. A lss vlu s considd to indict indqut covg nd s scod s gd gogphic miss. W hd pviously stblishd tht no study ptint fild to civ t lst 95% of th pscibd dos to 95% of th PTV in th pln bsd on th sm imging modlity. 36

59 Chpt : Plud Th impct of PET infomtion on dos limiting noml tissus including lung, spinl cod nd liv (fo tumous involving th gsto-osophgl junction) s lso vlutd ith DVH nlysis. Th pmts ssssd ; th volum of lung civing Gy (v), mximum spinl cod dos, nd th volum of liv civing 3 Gy (V3)..7.5 sults 3 ptints nolld on this pospctiv study. On ptint s xcludd bcus h s unbl to undgo PET/CT scnning in th quid diothpy ttmnt position, nd futh ptint s xcludd bcus th pimy osophgl tumou dmonsttd vy lo FDG-vidity. Of th mining ptints, (9%) hd tumous in th upp thid of th osophgus, 6 (9%) hd tumous in th middl thid nd 3 (6%) hd tumous in th lo thid o gsto-osophgl junction. Th ddition of PET infomtion ltd th clinicl stg in 8 of ptints (38%); 4 ptints (9%) found to hv distnt mtsttic diss [upstgd fom M to M (M in on ptint nd Mb in th ptints)] nd n dditionl fou ptints (9%) found to hv unsuspctd gionl nodl diss (upstgd fom N to N) tht s not ppnt on th initil stging CT scns (Tbl.7.5-). Th PET findings ld to chng in mngmnt fom dicl chmodition to ttmnt ith pllitiv intnt in fiv ptints (4%). Sixtn ptints pocdd to th diothpy plnning phs of th study nd civd dfinitiv chmodition plnnd ith th PET/CT dt st. Volumtic nlysis of GTV-CT nd GTV-PET shod tht PET-vid diss s xcludd fom th GTV in ptints (69%) if CT dt lon usd fo diothpy plnning. Th mdin pcntg volum of GTV-PET not includd in th GTV-CT s 38% (ng: %). To ssss th dqucy of covg of th GTV, simil compison of PTV-CT nd GTV-PET s pfomd, hich shod tht PET-vid diss s xcludd fom th PTV in fiv ptints (3%) if CT dt lon usd fo diothpy plnning. Exclusion of goss tumou fom th PTV in ths ptints ould hv sultd in gd gogphic miss. Th mdin pcntg volum of GTV-PET not includd in th PTV-CT s 6% (ng: 9%). Th gogphic misss involvd indqut covg of th pimy osophgl tumou in to ptints, xclusion of unsuspctd nodl diss fom th iditd volum in to ptints, nd combintion of both in on ptint. Evlution of th longitudinl xtnt of th pimy tumou in th osophgus by CT vs. PET CT s compd by ssssing th cnil nd cudl limits of GTV-CT nd GTVPET. Assuming PET psnts th tu xtnt of diss, CT ovstimtd th cnil xtnt of th tumou in six ptints by mdin vlu of.5 cm (ng:.4 3.4), nd undstimtd th cnil xtnt of th tumou in six ptints by mdin vlu of.7 cm (ng:.4.6). CT ovstimtd th cudl xtnt of th tumou in ight ptints by mdin vlu of.6 cm (ng:.4 5.5), nd undstimtd th cudl xtnt of th tumou in fiv ptints by mdin vlu of.3 cm (ng:.4 4.3). To ssss th dqucy of PTV covg, DVHs fo PTV-PET gntd fo th ttmnt pln bsd on CT infomtion lon, hich dmonsttd indqut covg of PTV-PET in six ptints (38%). Exclusion of potntil micoscopic tumou fom th PTV in ths ptints ould hv sultd in gd gogphic miss. As 37

60 Chpt : Plud dscibd bov, covg of th PTV s considd to b indqut if lss thn 95% of PTV-PET civd t lst 95% of th psciption dos. Th mdin pcntg volum of PTV-PET civing t lst 95% of th psciption dos fo th ptints ith gd gogphic miss s 86% (ng: 63 9%). Includd in this goup th fiv ptints ith gd gogphic miss. Figu shos n xmpl cs tht illustts th impct of PET infomtion on dlintion of tgt volums. Th upp pnl shos coonl nd sgittl constuctions of th GTV s dlintd by CT lon (GTV- CT in blu), hil th lo pnl shos coonl nd sgittl constuctions of th GTV s dlintd by PET/CT (GTV-PET in pupl). Th min diffnc is in th cnil xtnt of th pimy osophgl tumou, hich is high ith CT lon. In this cs, th PTV-CT (in d) compltly covs th GTV-PET so gogphic miss ould not hv occud. DVH nlysis s lso usd to ssss th impct of PET infomtion on dos limiting noml tissus. Th no cliniclly significnt diffncs on vg, in th dition doss to th lungs, spinl cod nd liv btn th ttmnt plns bsd on CT vs PET/CT (dt not shon). In gnl, incss in th GTV ld to incsd dition doss to th lungs nd liv, hil dcss in th GTV ld to ducd doss. In no cs did th dition doss xcd ou ccptd tolnc doss fo ths noml tissus (ith CT lon o PET/CT pln). Fig Upp pnl: coonl nd sgittl CT constuctions shoing th GTV s dlintd by CT lon (GTV-CT in blu). Not. Th GTV s not outlind using ths imgs, but on sil xil CT slics. Lo pnl: coonl nd sgittl PET/CT constuctions shoing th GTV s dlintd by PET/CT (GTV-PET in pupl). Th GTV-CT is lso shon in blu. In this cs, th cnil xtnt of th pimy osophgl tumou is high ith CT lon. Th PTV-CT (in d) compltly covs th GTV-PET so gogphic miss ould not hv occud. 38

61 Chpt : Plud Ptint P-PET stg PET findings Post-PET stg Chng fom dicl to pllitiv intnt TxNM Mtstss to bon nd TxNM Ys distnt nods in nck TxNM Mtstss to bon nd TxNM Ys biltl dnl glnds 3 TxNM Mtstss to gionl TxNM Ys nods nd distnt nods in th lft nck 4 TxNM Mtstss to bon TxNM Ys 5 TxNM Nodl diss upp TxNM Ys mdistinum nd lft pi-gstic 6-8 TxNM gionl nodl diss TxNM No TABLE.7.5- FDG-PET findings tht ltd clinicl stging nd ttmnt intnt. Not: Accut ssssmnt of T-stg s not possibl s th mjoity of ptints did not undgo ndoscopic ultsound..7.6 Imptus fo functionl imging fo contouing Th us of FDG-PET fo initil stging of osophgl cnc is ll stblishd. PET hs high snsitivity fo dtction of mtsttic diss thn dos th combind us of CT nd ndoscopic ultsound (EUS). In pospctiv study by Flmn t l. FDG-PET dmonsttd high ccucy fo dtction of mtsttic diss (8 vs 64%), minly du to supio snsitivity (74 vs 47%), tht sultd in th upstging of 5% of th ptints fom M to M diss 48. Ths findings simil to thos h h 9% of ptints found to hv distnt mtstss by PET. In this study, th GTV bsd on CT dt lon xcludd PET-vid diss in 69% of ptints, nd in 3% of ptints this ould hv sultd in gogphic miss of goss tumou. As th is no stndd dfinition in th diothpy littu fo ht constituts gogphic miss of tumou, th dfind fo th puposs of this study, to spt gds of gogphic miss. A gd gogphic miss s dfind s xclusion of ny goss diss (PETvid diss) fom th PTV. This constituts th most sious gd of gogphic miss sinc th cn b littl chnc of tumou cu if goss diss lis outsid th dition ttmnt filds. Although of lss impotnc, it is lso possibl tht gogphic miss could potntilly is fom indqut covg of th PTV though unddosing of gions contining micoscopic tumou. This hs bn tmd gd gogphic miss h covg of th PTV s considd to b indqut if lss thn 95% of PTV-PET civd t lst 95% of th psciption dos bsd on DVH nlysis. It should b notd tht ths pmts bitily dfind folloing n initil vi of PTV covg in th pln bsd on th sm imging modlity fo ptints compising th study cohot (s sction.7.4). Accoding to this dfinition, diothpy ttmnt plnning bsd on CT dt lon ould hv sultd in gd gogphic miss in 38% of ptints. 39

62 Chpt : Plud On of th min dvntgs of dding PET infomtion to CT-bsd plnning fo osophgl cnc is th bility to mo ccutly dfin th cnil nd cudl limits of th pimy tumou GTV. Cunt mthods fo dfining th longitudinl xtnt of th pimy tumou in th osophgus, such s CT nd osophgogphy pfomd t th tim of diothpy plnning, not lys ccut. PET llos th longitudinl xtnt of th tumou to b mo clly dfind, nd is pticully usful fo dtmining th cudl xtnt of tumous tht xtnd to th gstoosophgl junction nd poximl stomch, h visulistion ith CT lon is oftn difficult. In this study, th cnil xtnt of th pimy tumou s dfind by CT vs PET/CT diffd in ptints (75%), hil th cudl xtnt diffd in 3 ptints (8%). In contst to th longitudinl xtnt of th GTV, th dil xtnt, hich is dfind by th out ll of th osophgus, is usully clly visibl ith CT lon. Th dvntg of dding PET infomtion is thfo lss, xcpt hn dtmining th dil xtnt of tumous tht xtnd into th poximl stomch s dscibd bov. Pthoicl confimtion of tumou xtnt in th osophgus s not pfomd bcus it is not possibl to ccutly colt th upp nd lo tumou lvls msud on CT nd PET ith thos dtmind t ndoscopy. Futhmo, th limittions of ndoscopy in dtmining tu pthoicl tumou xtnt, nd som tumous inccssibl to ndoscopy du to tight stictuing. Although, pthoicl confimtion of PET findings is dsibl, this is not lys stightfod pocss, no is it ppopit in this goup of unsctbl ptints 66. Although incsd FDG could flct inflmmtoy chngs in ssocition ith tumoul uptk, pp by Choi t l. suggsts tht th tumou lngth on PET is n indpndnt pdicto of suvivl in ptints ith osophgl cnc, suppoting th contntion tht it mo ccutly flcts tumou xtnt thn convntionl imging tchniqus nd thfo ought to b includd in th GTV 67. An impotnt finding is tht PET s bl to dtct unsuspctd gionl lymph nods in th ptints tht ould not hv bn ncompssd in th CT-dlintd volum. A limittion is tht not ll lymph nods dtctd by PET smpld pthoiclly, ith th potntil fo fls positiv sults. Hov, givn th high spcificity of PET fo dtcting nodl diss, th liklihood of fls positiv sult is lo nd PET hs bn potd in svl studis to b mo ccut thn CT nd EUS 5,54,55,56. In ths studis, th mjo limittion of PET s its inbility to dtct pi-tumoul nods. This likly lts to th sptil solution limits of PET. Ths nods thos tht most likly to b smpld pthoiclly, lloing dtction of vn smll volum diss blo th solution of ny imging modlity. Hov, such pitumoul nods lss likly to b of significnc to dition ttmnt plnning compd to mo distnt gionl nods sinc thy ncssily includd in th ttmnt volum vn if not indpndntly solvd on PET. Suppoting this contntion, cnt study ssssing th pognostic significnc of vious PET findings dmonsttd tht in ptints ith pthoicl stg III diss (gionl nodl mtstss), th s significntly supio suvivl in thos ithout disct nodl bnomlitis on PET (fls ngtivs) compd to thos ith this finding (tu positivs) 67. Bcus most dition oncoists not dqutly tind in th intpttion of PET, it s flt impotnt tht n xpincd PET spcilist b vilbl to both confim tht th ptint hs no mot mtsttic diss nd to ssist ith contouing of th GTV. In ll css, intpttion of th PET findings s pfomd by skilld 4

63 Chpt : Plud imging spcilist ith tining nd xpinc in oncoicl PET tking into ccount knoldg of th ntul histoy of th diss, clinicl infomtion, nd pttn cognition. Fo th puposs of incopoting th infomtion fom oth coltiv imging sults into th GTV-PET, dioists ith dul tining in stuctul nd PET imging usd in this study. As ith th us of oth imging modlitis, pthoicl confimtion s pfomd hn th s doubt bout th PET findings. With ths cvts, th sults of this study dmonstt tht if combind PET/CT is usd fo diothpy ttmnt plnning, th ill b lttions to th dlintion of tumou volums hn compd to CT lon. If PET/CT is ssumd to mo ccutly dtct diss xtnt, thn ttmnt bsd on CT lon my potntilly sult in gogphic miss of tumou. Bcus pthoicl vifiction of PET findings s not pfomd, th is th potntil fo fls positiv sults ith th isk of ov ttmnt nd incsd toxicity. Hov, th clinicl consquncs of ov ttmnt significntly lss thn thos of gogphic miss if PET-vid gions not includd in th dition ttmnt filds. A futh cvt ith th us of PET is tht fls ngtiv findings my occu ith smll volum tumous (T ) o thos tht not FDG vid. In ou xpinc, FDG non-vidity is uncommon ith osophgl cnc (4% in this sis), nd th vst mjoity of ptints ttd ith diothpy ill hv loclly dvncd tumous (T 3). Although not dvocting tht PET should b th n gold stndd, it is blivd tht th us of combind PET/CT infomtion fo diothpy ttmnt plnning is n impovmnt on th stndd of CT lon nd should tk pcdnc ov oth non-invsiv stging tchniqus hn discodnc cnnot othis b solvd. Whth impovmnts in tgt volum dlintion nd ttmnt plnning ill tnslt into btt clinicl outcom mins to b dtmind nd ill qui suppotiv vidnc fom lg, multi-institutionl tils vluting locl tumou contol, suvivl nd ttmnt toxicity..8 Ictl SPECT imgs SS is tchniqu coupling img guidd nuosugicl intcnil loclistion tchniqus ith singl dos xtnl bm idition to chiv non invsiv ttmnt of smll, sily visulisd lsions. Th TPS (XKnif T, dionics, Bulington, MA, USA) llos th outin us of CT nd Mgntic sonnc Imging (MI) imgs fo stotctic ttmnt plnning of mdicl lin cclto bsd diosugy. Ictl (duing sizu) SPECT ith Tchntium-99m is th pfd imging modlity fo pilpsy 68. Ictl SPECT imgs cquid t th NM dptmnt of th Austin nd ptition Mdicl Cnt (AMC) hv bn incopotd into th stotctic diosugicl ttmnt plnning t th Willim Bucklnd diothpy Cnt (WBC) of th Alfd Hospitl. Th oiginl ictl SPECT imgs consistd of 65 slics sptd by.3 mm coving n xil fild of vi (FOV) of 49 mm, ch slic md up of 8 by 8 squ pixls of sid lngth.8 mm coving tnsxil FOV of sid lngth 3 mm. Th sptil solution of th SPECT imging systm s nominl 8 mm full idth t hlf mximum. In consulttion ith th WBC, th volumtic SPECT dt s co-gistd t th AMC ith volumtic MI dt st, tchniqu tht hs bn vlidtd by O Bin t. l. 69. Both th oiginl MI nd th -smpld cogistd SPECT img dt sts thn svd in AW pixl only fomt, 56 by 56 pixls p slic, 4 slics, 6 bits p pixl, littl ndin intg fomt. Ths imgs could not b impotd dictly into th WBC stotctic TPS. Although th TPS suppotd th impottion nd us of DICOM 7 fomt CT nd MI, it did not suppot th impottion o disply of SPECT imgs 7. Additionlly, dionics 7 did not hv AW to DICOM 4

64 Chpt : Plud convt vilbl. At this point th PMCI undtook to ct tnslto fom AW to DICOM fomt, so tht th AW SPECT img s ffctivly mbddd in th pixl dt sction of multipl DICOM CT fils foming pt of DICOM PAT confomnt img st. In this y th SPECT dt ould b split up nd ssmbld insid th xknif comput und th lis of CT img. Th fist ttmnt nt hd s plnnd t th WBC. This sction dscibs th implmnttion of th AW to CT nd AW to MI convsion..8. Clinicl Pocdu Th MI nd SPECT scns initilly pfomd six ks pio to th ttmnt of th ptint. Th to scns co gistd nd th SPECT scn s smpld nd tnsfomd to ct n SPECT scn tht hd th sm numb of slics, ointtion, positioning nd gomticl fm of fnc s th Mgntic sonnc (M) scn. Th oiginl M scn nd th n SPECT scn thn xpotd s to AW fomt img fils. Ths to AW fomt imgs thn tnsltd into to DICOM fil sts. Osiis 7 s usd to ct DICOMDI 73 fo ch fil st, nd th to filsts ith thi spctiv DICOMDIs thn bunt onto CD-om in to spt subdictois. Th M scn s psntd s DICOM M fil st, th SPECT scn s psntd s DICOM CT fil st. A k pio to th ttmnt th img dt in th fil sts s uplodd into th TPS systm using th img tnsltion utility, nd t tht tim p-inspction of th M nd SPECT(CT) dt s don bfo th booking fo ttmnt s confimd. On th ttmnt dy stotctic CT scn s pfomd ith th BW hd ing 74 nd loclistion fm ttchd. Onc th M nd SPECT img sts convtd to DICOM th fils lodd into th TPS Img Fusion modul. Th stotctic CT nd th M dt s lodd fist nd th fusion pfomd s noml. Th Img Fusion modul quis th us to slct minimum of th lndmk positions bfo th fusion pocss cn bgin. It is xtmly difficult to lndmk ntomicl fncs 75 on functionl (SPECT) dtst du to th bsnc of ntomicl infomtion. Usully xtnl fudicil mks usd hn functionl fusion is pfomd 76. Th fusion of th M nd CT dt sults in th ction of tnsfom fil tht spcifis th tnsfomtion usd to mp th M dtst into th stotctic CT coodint systm. As th M nd SPECT(CT) dtsts psnt xctly th sm volum, th SPECT(CT) tnsfomtion to mtch th stotctic CT is idnticl to th M tnsfomtion. Th M tnsfom fil s copid nd nmd s th SPECT(CT) tnsfom fil. Th Img Fusion modul s lodd s noml ith th CT nd th SPECT(CT) img sts slctd. Th Img Fusion modul thn dtmind tht tnsfom (fusion) hs ldy bn pfomd, by ding th SPECT tnsfom fil, nd so lodd th SPECT dtst in th tnsfomd ointtion. Th fusion of th CT nd th SPECT s thn vid nd chckd ginst hd copis of th M SPECT ovlys. Th fusion s svd nd th ttmnt plnning commncd. 4

65 Chpt : Plud.8. Convsion fom AW fomt to DICOM Filst To poduc DICOM Fil st fom AW dt fil quis tht ch slic of th AW dt fil b incopotd into spt DICOM Dt St, pcdd by th DICOM Fil Mt Infomtion to fom fil. So ch AW dt fil contining 4 slics hd to b split into 4 spt DICOM fils. This is shon schmticlly in Figu.8.- Fig..8.- Fil tnsltion schmtic..8.3 Fil Mt Infomtion Th Fil Mt Infomtion includs idntifying infomtion on th ncpsultd dt st 73 s ll s spcifying th ncoding uls fo th sm. Th DICOM Fil Mt Infomtion itslf is ncodd s stm of byt dt tht consists of pfix of 8 byts tht not d, follod by th fou chcts DICM(HEX D), follod by th sis of DICOM Dt lmnts listd und Fil Mt Infomtion. Th stuctu of th Fil Mt Infomtion DICOM Dt lmnts is shon in Figu Fig DICOM Dt St nd Dt Elmnt Stuctu fo Fil Mt Hd Vl p is contction stnding fo Vlu psnttion, to byts tht dfin th ncoding uls fo th vlu fild. Vl Ln is contction stnding fo Vlu Lngth, to byt intg qul to th lngth of th vlu fild in byts. 43

66 .8.4 Uniqu idntifis in th Fil Mt Infomtion Chpt : Plud Th fou uniqu idntifis in th Fil Mt Infomtion, hich sv to unmbiguously spcify th typ of img psntd, th ncoding uls fo tht img, th ppliction tht lst modifid th fil, nd th sil numb of th fil, s spcifid blo. Th Mdi Stog SOP Clss UID (,) is dfind by th DICOM potocol. It spcifis th ntu of th objct tht th DICOM fil psnts nd is quid to b fo CT Img 73, o fo n MI Img 73. Th Tnsf Syntx UID (,) is lso dfind by th DICOM potocol. It spcifis th ncoding uls fo th DICOM Dt st (But not th Fil Mt Infomtion). Fo th idst possibl gnlity chos th dfult DICOM tnsf, Implicit V Littl Endin, dsigntd by UID hich ll DICOM pplictions quid to suppot. Implicit V mns tht th vlu psnttion tg is omittd fom th DICOM Dt, nd th vlu psnttion of spcific dt lmnt is only idntifid indictly by its goup nd itm numb. Littl Endin fs to th byt oding of intgs, th lst significnt byt is ncodd fist. Th pixl dt is tnsmittd in ntiv, uncompssd fomt. Th DICOM dt st nd dt lmnt stuctu fo th dfult syntx is shon in Figu Fig DICOM Dt St nd Dt Elmnt Stuctu fo Dfult DICOM Tnsf. This is spcilistion of Figu 7.. fom Pt 5. Th Implmnttion Clss UID (,) idntifis uniquly th lst ppliction tht ot to th fil. To nsu tht th UID is uniqu, th uthoisd us of th UID pfix s gciously povidd by Dvid Hvy of Mdicl Connctions 77. Th spcific UID of s ssignd to this pogm. All fils ctd ith this pogm stmpd ith this UID. Th Mdi Stog SOP Instnc UID (,3) idntifis uniquly ch DICOM fil. In od to gunt tht th UID is uniqu, th fomt is st to mk th UID uniqu to th pogm, comput, nd tim (to th scond) tht th pogm is sttd. Th UIDs poducd ithin singl xcution of th pogm thn incmntd to mk thm ll diffnt. This gunts tht th UID ill b uniqu unlss th sm pogm is un t th sm tim don to th nst scond on th sm mchin. This is givn to b sufficintly unlikly to occu tht it is considd sufficint simply to instuct th us to nsu tht it dos not occu..8.5 DICOM Dt St Th contnts of ch DICOM Fil includs th Fil Mt Infomtion follod by th DICOM Dt St. Th DICOM stndd dfins 6 diffnt vlu psnttions, o dt typs, hich spcify th y th infomtion is 44

67 Chpt : Plud ncodd into squnc of byts. To constuct DICOM fil quis tht of th 6 usd to ncod mndtoy dt in th DICOM shll ound th pixl dt fo ch slic. Th most involvd pt of th pojct s coding ll th xtnous dt tgs tht quid und th DICOM stndd s pt of th DICOM DATA St. Ths dt lmnts spcifid s ith typ, C,, C o 3. Typ lmnts mndtoy, thy must b psnt nd thy must hv vlid infomtion contnt. Typ C lmnts conditionlly mndtoy. Thy not quid und ll css, but if thy quid thn thy must hv vlid contnt. Typ lmnts must b psnt but thy cn hv zo dt lngth. Typ C lmnts not quid und ll css, but if thy quid thn th dt lngth cn b zo. Typ 3 itms ntily optionl. Dt lmnts lso spcifid by uniqu combintion of goup numb nd lmnt numb. Unlss foming pt of squnc, th od of ppnc of dt lmnts is mndtd by th goup numb nd lmnt numb, thy must b in incsing od. Th list of DICOM lmnts quid is obtind by fist xmining th COMPUTED TOMOGAPHY IMAGE OBJECT DEFINITION nd th MAGNETIC ESONANCE INFOMATION OBJECT DEFINITION, to dtmin th quid moduls in ch cs. Thn ch of ths moduls s schd though to find ll th typ, C, nd C itms. Also on typ 3 itm, th Slic Loction, is includd in th list bcus it s knon tht this is o hd in th pst bn quid by som diothpy systms..8.6 Implmnttion Figu.8.6- shos SPECT dt s vid in th contouing indo of th stotctic ttmnt plnning systm. Fom inspction th tgt volum is too smll to hv bn mkd solly fom th lo sptil solution SPECT imgs. Effctivly th SPECT img ds ttntion to n idntifibl ntomicl gion in th high sptil solution co-gistd MI imgs; sction (.8.) dls ith SPECT img solution. Th imgs ndd ith bilin intpoltion, hich is suitd to th disply of CT nd MI, th thn th nst nighbou intpoltion oftn usd in NM img disply 37 (S sction.5.3). Fig Ictl SPECT dt s vid in th contouing indo of th stotctic ttmnt plnning systm. Not th lg numbs in th indo lvl stting. Th smll hit cicl is th outlin of th cicul stotctic collimto usd fo ttmnt, cntd on th ttmnt isocnt. Th dk stuctu outlind ithin it is th spct_lsion. 45

68 .8.7 c to implmnttion Chpt : Plud Th ok s quid to b compltd ithin gnous but limitd clinicl timtbl. Svl options considd fo impoting th SPECT imgs into th TPS, but to quickly mgd s th most vibl. Option s to convt fom AW dict to im, th intnl dt fomt of th TPS. This hd th dvntg tht th im fomt s xpctd to hv only minimum xtnous ptint dmogphic dt in it, just th ptint nm nd vitl sptil infomtion. Th disdvntg s tht did not hv ny documnttion bout th img fomt, nd dionics not bl t th tim to povid AW to im convt. Consquntly option s chosn, hich s to convt fom AW to DICOM, nd thn impot th sulting DICOM fils into th TPS using th stndd TPS utilitis. Th disdvntg s tht mny ptint dmogphic dtils nd DICOM tnsf syntx spcifictions ould nd to b ddd to th img. Th mjo dvntg s tht th DICOM stndd s ll documntd if complx. Also DICOM tnslto ould b mo gnlly usful nd might b dptbl to oth puposs. It s dcidd to it commnd lin divn utility using th C-compil bundld ith th xknif comput. This ould llo oth sits to modify nd compil th souc fo pticul quimnts, but ould qui using th p ANSI Knighn nd itchi vsion of th C pogmming lngug 78, ithout n intgtd compil nvionmnt to it th pogm..8.8 Ointtion of th img sts Th TPS fusion modul displys mks fo lft, ight, supio, infio, ntio nd postio s ppopit fo th fild of vi. Although th img fusion ill ng th img in th ight ointtion by tnsltion tc, th vi is disconcting if th mks clly in th ong plc. Also th is th possibility of mio flction h on o ll of th th mk pis vsd, fom hich th fusion modul ill not ncssily b bl to povid tnsfomtion to cov th ight hnddnss of th img coodint systm. It is thfo dsibl tht hn th imgs tnsltd fom AW to DICOM th ointtion of th img cn b spcifid, nd commnd lin sitchs to dsignt th sulting DICOM fil st s psnting coonl, sgittl o xil plns implmntd to llo th spcifiction of th ointtion. Th TPS implmnts viing of imgs in th dioicl convntion 79,8, nd it is vitlly impotnt to void mispsnting th lft sid of th ptint s th ight sid in th img spc. Fom inspction vn th untind y cn dtmin supio fom infio, nd ntio fom postio, but th ppoximt symmty of th humn fom mks it difficult to dtmin ight fom lft nd hd to vify this. In this pticul cs th s significnt dficit on th ptints ight sid tht s clly visibl in th M nd SPECT scns, hich md it sy to diffntit lft fom ight. Th byt oding ithin th AW dt sts is chosn bitily t th tim of xpot to th AW fomt fom th imging modlity, so it is impotnt to hv hdcopy output fom th imging modlity tht shos th ointtion of th img st fo vifiction puposs. Altntivly th plcmnt of Tchntium-99m lodd fiducil on spcifid sid of th SPECT img pln is oth considing..8.9 Dk ithin th SPECT dt. Whn th SPECT dt st s smpld to fom n SPECT dt st in th sm gomticl fm of fnc s th MI dt st, thos s of th M dt st fo hich th s no mtching SPECT dt ssignd s 46

69 Chpt : Plud hving zo pixl vlu. This cn b sn s th dk t th bottom of th fist to SPECT slics shon in Figu.8.-. Th psnc of this tfct cusd som lck of confidnc in th tnsltion fom AW to DICOM, until it s pointd out tht th stotctic ttmnt pogm fusion lgoithm lso poducs dk s. Clinicl confidnc in gisttion is cuing thm coss implmnttion of diffnt functionl imging modlitis..8. Byt oding Th tnsltion fom AW to DICOM ssums tht th AW pixl dt is ncodd s 6 bit Littl Endin (lst significnt byt ncodd fist) fomt intgs. It is xpctd tht AW xpot fom imging modlitis is configubl to ith littl ndin o big ndin(most significnt byt ncodd fist), so tht this spcifiction is no impdimnt s long s it is knon bout bfo th xpot is don..8. SPECT img sptil solution nd stotctic loclistion ccucy It ould sm t fist inspction SPECT imging is of qustionbl us fo stotctic ttmnt, sinc th stngth of stotctic diosugy is th ccucy of th sptil loclistion, nd this ould b compomisd by th lo sptil solution of th SPECT dt. It is ppnt fom inspcting Figu.8.6- shoing th tgt volum mkd on th SPECT dt tht th contou hs bn mkd ith btt solution thn is vilbl fom th SPECT img. Th co-gisttion ith th MI dt llos th SPECT img to flg gnl, hich cn b discnd btt on stuctul bsis fom th supio sptil solution MI img. Th combintion of th lo sptil solution SPECT imgs dpicting functionl infomtion fusd to th high sptil solution MI imgs shoing stuctul infomtion is suitbl fo diosugicl ttmnt plnning..8. DICOM bodcst of SPECT dt vs. movbl mdi ction Initilly it s poposd to bodcst th DICOM dt fils to xknif using OFFIS 8. With th dionics DICOM Sv st to uto-tnslt, if ch fil s snt by spt cll to th stoscp biny, ch scn ould ovit th pvious on nd instd of n img st ith 4 slics n img st ith only on slic ould b ctd. To obtin multi-slic img st quid th DICOM fils to b snt using singl cll of th stoscu pogm. Bsids bing cumbsom this ffctivly limitd th img sts to 56 slics (Limit of 64 commnd lin gumnts, including 6 quid DICOM potocol tnsmission spcifictions). This limittion s ovcom by sving th DICOM dt sts onto CD-OM nd impoting th DICOM fil sts fom th CD-OM using th TPS img tnsltion tools. Subsquntly it s found tht th full 4 slics of th DICOM filst could hv bn bodcst to th stotctic ttmnt plnning systm if th DICOM sv hd simply bn configud not to utomticlly tnslt imgs. 47

70 Chpt : Plud.8.3 quimnt to scl th pixl vlus of th DICOM SPECT(CT)dt sts Th stotctic ttmnt plnning systm ill only disply pixl vlus btn nd 495, but th SPECT dt usd th full 6 bit dt solution to povid pixl vlus fom to 65,535. It s thfo ncssy to divid th SPECT AW pixl vlus by 6 bfo iting thm into th SPECT(CT) DICOM Filst Fils. Th sist y of doing this ould hv bn to chng th scl slop (8,53) to non unity vlu, but this mthod s not chosn bcus linc on th coct intpttion of th scl slop by DICOM sv s dmd not dvisbl. Th 6 bit intgs compising th pixl dt ll scld instd, s mo obust but lss fficint y of chiving th quid scling..8.4 Outcom SPECT dt s succssfully intgtd into th stotctic TPS in tim fo plnning of stotctic diosugy, nd th initil ttmnt s dlivd on schdul. Th invstmnt of significnt soucs to chiv this s motivtd pimily by th clinicl quimnts of th fist cs but s sustind by th going intst in SPECT fo ttmnt plnning. With ltiv s th mthod could b gnlisd to incopot SPECT dt into oth diothpy plnning systms, s ll of thm suppot impot of DICOM CT dt. Th csting of SPECT img s CT img is tchniclly goss violtion of th DICOM potocol, but it is considd justifid in this cs bcus th pofssionl intpttion of th imgs is nhncd by nbling thm to b vid ithin th stotctic ttmnt plnning systm. Th concis spcifiction of th minimum ncssy quimnts to ct DICOM Pt Complint Fil St pticul to CT nd M, colscd fom th thousnds of pgs of th DICOM stndd, my b of vlu to oths ho qui fo clinicl puposs to ct CT o M DICOM fil sts. dionics hv infomd us tht thy pln to incopot PET imgs, nd phps SPECT imgs, s pt of thi poduct dvlopmnt. Apt fom this futh vindicting ou ndvous, hv lso bn in position to povid dvic on ho this could bst b don..9 Motivtion Th poblms cu thoughout ths ndvos to liz th syngy of functionl nd ntomicl imging. Fist, th s lys unctinty bout ho to sgmnt tumous fom PET imgs, th most bsic mnifsttion of hich s n unctinty ov ht gyscl lvl to us fo th boundy of th tumou. Scondly, nomous ffots quid to nbl th flo of infomtion in digitl fom, to th xtnt tht th implmnttion of nti clinicl pogms obstuctd solly by difficultis ith dt tnsf. Thidly th s lys nd to cogist th functionl imging, t th outst to ntomicl foms of imging fo stging but ultimtly to th ttmnt isocnt fo tumou volum mking. Ths th coupld poblms must b ddssd to nbl soundly foundd clinicl tils to stblish th clinicl fficcy of hybid imging fo tumou volum mking in diothpy. 48

71 . Thsis stuctu Chpt : Plud Th poblm of tumou sgmnttion is th motivtion fo th cntl ok of chpt, th study of Edi s nd oth thshold mthods tht consid th simplst poblm in PET img tumou sgmnttion, finding th boundis of sttiony, sphicl, unifom concnttions of FDG. It is shon tht fo -D PET, qulittiv xplntion of thsholds cn b chivd by pplying simpl Gussin bluing modl, nd quntittiv xplntion of thsholds cn b chivd by dding n stimtion of nois ffcts. Divs publishd sults fom th littu shon to b xplinbl by th sm modl. A publiction is in pption bsd on this ok. Th poblm of infomtion tnsf is th motivtion bhind th dploymnt in chpt 3 of DICOM Pckt Sniffing. This chpt shos ho DICOM pckt sniffing cn b usd to pinpoint th cus of poblms in multi vndo nvionmnt, to guid solutions tht cn b implmntd ith locl soucs, nd tht som infomtion tnsf poblm cn only b solvd by th ppliction of this tchniqu. This chpt foms th bsis of pp tht hs bn publishd in th jounl Austlsin Physicl nd Engining Scincs in Mdicin 8. Th gnl poblm of clinicl confidnc in co-gisttion is cuing thm coss ll foms of functionl imging. Th spcific poblm of co-gisttion to th ttmnt isocnt is considd in its most dmnding fom in diothpy, stotctic fmlss intcnil ttmnt. Th pincipl of ottionl invinc is usd to div nd tst univslly pplicbl mthod of dtmining th sptil ccucy of gisttion to th isocnt. This is usd to stblish ccucy sufficint fo clinicl pctic, guid chngs in ttmnt tchniqu, xplo coltion of ccucy ith distnc movd, th numb of coctions quid, nd th fction of ttmnt. Th ccucy to hich th ptint is ottd to th coct ngl is lso vid by pplying th sm mthod dptd to ottion th thn tnsltion. Atifcts of th mthod stimtd using combintion of optimiztion nd sttisticl stimtion. This ppliction of th pincipl of ottionl invinc fomd th bsis of pp publishd in Mdicl Physics 83. A follo up pp is bing ppd fo submission to th jounl Austlsin Physicl nd Engining Scincs in mdicin. 49

72 Chpt : Plud (fncs) Noln DJ. ys of x-ys. B Md J 995;3:64. Gubbé EH. Pioity in th Thputic Us of X-ys. dioy 993;: Koglnik HD. Inugution of diothpy s n scintific spcility by Lopold Fund ys go. dioth Oncol 997;4:3-. 4 Hdy WA, Gindon J. Hndbook of Cutnous Thputics. Phildlphi & N Yok: L Boths & Co, Kst DW. Histoicl dvlopmnt of th btton. Ntu 946;57: Widø. Achiv Elktonik und Ubtgungstchnik 98;: otblt J. Obituy: Mk Oliphnt (9-). Ntu ;47: Ambos J, Hounsfild G. Computizd tnsvs xil tomogphy. B J diol 973;46: St WH, Bonll GL. Locliztion of bin tumos ith positon mitts. Nuclonics 953; :4-45. Jszczk J. Th ly ys of singl photon mission computd tomogphy (SPECT): n nthoy of slctd miniscncs. Phys Md Biol 6;5:99. Intntionl Commission on dition Units nd Msumnts Pscibing,coding nd poting Photon Bm Thpy (Supplmnt to ICU pot 5) (999) Lunns G, Mntn J, Wltns C, Vstt J, vn d Schun E. Qulity ssssmnt of mdicl dcision mking in dition oncoy: vibility in tgt volum dlintion fo bin tumous. dioth. Oncol., 993;9: Quint LE, Fncis I, Whl L, Goss BH, Glz GM. Poptiv stging of non-smll cll ccinom of th lung: imging mthods. Am J ontgnol 995;64: Snn S, vn Sönsn d Kost J, Smson M, Tnkink H, Jnsn P, Nok PJ, Kol AD, Schmitz P, Lgd FJ. Evlution of tgt contouing potocol fo 3D confoml diothpy in non-smll cll lung cnc. dioth Oncol. 999;53: McMnus MP, Hicks J, Bll DL, Klff V, Mtths JP, Slminn E, Kh P, With A, ischin D, McKnzi AF. 8 fluoodoxyglucos positon mission tomogphy stging in dicl diothpy cndidts ith non smll cll lung ccinom: poful coltion ith suvivl nd high impct on ttmnt. Cnc ;9: Mgui GQ. Noz ME. Img fomts: fiv ys ft th AAPM stndd fo digitl img intchng. Md Phys 989;6: Ackly T, Gso M, Cmb J. Plnning of fixd fild Stotctic diothpy using Stotctic Loclising Pogm nd gul Ttmnt Plnning Systm. Md Phys 998;5:A93. 8 Ackly T, Ands J, Bll D, Guii M, Hly B, Willims I. Discpncis in volum clcultions btn diffnt diothpy ttmnt plnning systms. Austls Phys Eng Sci Md 3;6: Hll D, Fguson SP. Th Dfinitiv Guids to th X Windo Systm, Volum Six A Motif Edition Motif Pogmming Mnul fo OSF/Motif ls.. nd dn. USA:O illy & Associts, 994 Islm MK, Sdi F, Al-jhi N. A simplifid shilding ppoch fo limiting ftl dos duing dition thpy of pgnnt ptints. Int J dit Oncol Biol Phys ;49: Jnkhi B. Cunt sttus nd histoy of tldioy in Indi. Int J Md Inf ;6: Guyton AC. Txtbook of Mdicl Physioy. 8 th d. Phildlphi:W.B.Sunds, Gonzlz C, Woods E. Digitl img pocssing. ding Msschusts:Addison Wsly,

73 Chpt : Plud (fncs) 4 McMnus MP, Wd M, Mtths JP, Bll DL. Chctistics of 49 ptints ho suvivd fo 5 ys folloing dicl dition thpy fo non-smll cll lung cnc: th potntil fo cu. Int J dit Oncol Biol Phys ;46: Schfsm J, Coy P. Th ffct of diothpy on th suvivl of non-smll cll lung cnc ptints. Int J dit Oncol Biol Phys 998; 4: Mc, Choy H. Concunt chmodiothpy fo inopbl stg III non-smll-cll lung cnc. Cu Oncol p 3;5: Dillmn O, Sgn SL, Popt KJ t l. A ndomizd til of induction chmothpy plus high-dos dition vsus dition lon in stg III non-smll-cll lung cnc. N Engl J Md 99;33: Sunds M, Disch S, Btt A, Hvy A, Gibson D, Pm M. Continuous hypfctiontd ccltd diothpy (CHAT) vsus convntionl diothpy in nonsmll-cll lung cnc: ndomisd multicnt til. Lnct 997;35: Ptl, Mht M. Th-dimnsionl confoml diothpy fo lung cnc: pomiss nd pitflls. Cu Oncol p ;4: Stphnson JA, Wily AL J. Cunt tchniqus in th-dimnsionl CT simultion nd dition ttmnt plnning. Oncoy 995;9: D Lyn P, Vnstnkist J, Cuyps P t l. ol of cvicl mdistinoscopy in stging of non-smll cll lung cnc ithout nlgd mdistinl lymph nods on CT scn. Eu J Cdiothoc Sug 997;:76. 3 Gddo A, Vn Schil P, Cothouts B, Vn Mighm F, Vn Mbck J, Vn Mck E. Pospctiv vlution of computd tomogphy nd mdistinoscopy in mdistinl lymph nod stging. Eu spi J 997; : Dmn BA, Sonnd SS, Angobldo JO, Whl L. Mtstss fom non-smll cll lung cnc: mdistinl stging in th 99s mt-nlytic compison of PET nd CT. dioy 999;3: McMnus MP, Hicks J,Mtths JP t l. High t of dtction of unsuspctd distnt mtstss by pt in ppnt stg III non-smll-cll lung cnc: implictions fo dicl dition thpy. Int J dit Oncol Biol Phys ;5: Vnstnkist JF, Stoobnts SG. Positon mission tomogphy in th mngmnt of nonsmll cll lung cnc. Hmtol Oncol Clin Noth Am 4; 8: Vnuytsl LJ, Vnstnkist JF, Stoobnts SG t l. Th impct of (8)F-fluoo--doxy-Dglucos positon mission tomogphy (FDG-PET) lymph nod stging on th dition ttmnt volums in ptints ith non-smll cll lung cnc. dioth Oncol ;55: Ackly T, Ands J, Bll D t l. Disply of positon mission tomogphy ith Cdpln. Austls Phys Eng Sci Md ; 5 : Nstl U, Wlt K, Schmidt S t l. 8F-doxyglucos positon mission tomogphy (FDG- PET) fo th plnning of diothpy in lung cnc: high impct in ptints ith tlctsis. Int J dit Oncol Biol Phys 999; 44: Mh K, Cldll CB, Ung YC t l. Th impct of (8)FDG-PET on tgt nd citicl ogns in CT-bsd ttmnt plnning of ptints ith pooly dfind non-smll-cll lung ccinom: pospctiv study. Int J dit Oncol Biol Phys ;5: Bdly J, Thostd WL, Mutic S t l. Impct of FDG-PET on dition thpy volum dlintion in non-smll-cll lung cnc. Int J dit Oncol Biol Phys 4; 59: Edi YE, osnzig K, Edi AK t l. diothpy ttmnt plnning fo ptints ith nonsmll cll lung cnc using positon mission tomogphy (PET). dioth Oncol ; 6: Hung SC. Antomy of SUV. Nucl Md Biol ; 7:

74 Chpt : Plud (fncs) 43 Dyck S, D Gsm W, Vn Duys BB, D Nv WC. Confoml diothpy of stg III non-smll cll lung cnc: clss solution involving non-copln intnsity-modultd bms. Int J dit Oncol Biol Phys 998; 4: Coi L, Minsky BD, John MJ, t l. Th vlution nd ttmnt of ptints civing dition thpy fo ccinom of th sophgus: sults of th Pttns of C Study. Cnc 999;85: Coop JS, Guo MD, Hskovic A, t l. Chmodiothpy of loclly dvncd sophgl cnc: long-tm follo-up of pospctiv ndomizd til (TOG 85-). JAMA 999;8: Hskovic A, Mtz K, l-sf M, t l. Combind chmothpy nd diothpy compd ith diothpy lon in ptints ith cnc of th sophgus. N Engl J Md 99;36: Stnbkks J, Duppn JC, Fitton I, t l. Obsv vition in tgt volum dlintion of lung cnc ltd to dition oncoist-comput intction: Big Both vlution. dioth Oncol 5;77: Flmn P, Lut A, vn Cutsm E, t l. Utility of positon mission tomogphy fo th stging of ptints ith potntilly opbl sophgl ccinom. J Clin Oncol ;8:3. 49 Knist W, Schcknbg M, Btnstin P, Gunld F, Obholz K, Junging T. Positon mission tomogphy fo stging sophgl cnc: dos it ld to diffnt thputic ppoch? Wold J Sug 3;7:5. 5 Wn SM, Stijns P, Sinivs S. Positon mission tomogphy in th initil stging of sophgl cnc. Ach Sug ;37: 6. 5 Bujnovic S. Th ol of positon mission tomogphy in dition ttmnt plnning. Smin Nucl Md 4;34: Choi JY, L KH, Shim YM, t l. Impovd dtction of individul nodl involvmnt in squmous cll ccinom of th sophgus by FDG PET. J Nucl Md ;4: Kto H, Miyzki T, Nkjim M, t l. Th incmntl ffct of positon mission tomogphy on dignostic ccucy in th initil stging of sophgl ccinom. Cnc 5;3: Lut T, Flmn P, Ectos N, t l. Histopthoic vlidtion of lymph nod stging ith FDG-PET scn in cnc of th sophgus nd gstosophgl junction: pospctiv study bsd on pimy sugy ith xtnsiv lymphdnctomy. Ann Sug ;3: Luktich JD, Fidmn DM, Wigl TL, t l. Evlution of distnt mtstss in sophgl cnc: conscutiv positon mission tomogphy scns. Ann Thoc Sug 999;68: Yoon YC, L KS, Shim YM, Kim BT, Kim K, Kim TS. Mtstsis to gionl lymph nods in ptints ith sophgl squmous cll ccinom: CT vsus FDG PET fo psugicl dtction-pospctiv study. dioy 3;7: Ggoi V. Is th ny futu in diothpy plnning ithout th us of PET: unvling th myth. dioth Oncol 4;73: Viz O, Hustmns K, Wv WD, t l. Is th ol fo FGD-PET in diothpy plnning in sophgl ccinom? dioth Oncol 4;73: Giud P, Ghk D, Montvs F, t l. CT nd (8)F-doxyglucos (FDG) img fusion fo optimiztion of confoml diothpy of lung cncs. Int J dit Oncol Biol Phys ;49: Lvnkov K, Ptidg M, Cook G, Bd M. Positon mission tomogphy fo tgt volum dfinition in th ttmnt of non-smll cll lung cnc. dioth Oncol 5;77: 4. 5

75 Chpt : Plud (fncs) 6 Gts X, Disn JF, Ggoi V, Hmoi M, Lonnux M. ol of -C-mthionin positon mission tomogphy fo th dlintion of th tumo volum in phyngo-lyngl squmous cll ccinom: compison ith FDG-PET nd CT. dioth Oncol 4;7: L YK, Cook G, Flo MA, t l. Addition of 8F-FDG-PET scns to diothpy plnning of thocic lymphom. dioth Oncol 4;73: Nishiok T, Shig T, Shito H, t l. Img fusion btn 8FDG-PET nd MI/CT fo diothpy plnning of oophyngl nd nsophyngl ccinoms. Int J dit Oncol Biol Phys ;53: McMnus M, Hicks, Byn M, Long T, Pts L, Bll D. In gd to Pulino nd Johnston: Us of PET nd CT imging dt in dition thpy plnning. Int J dit Oncol Biol Phys 4;59:4 5. Int J dit Oncol Biol Phys 4;6: Nstl U, Kmp S, Schf-Schul A, t l. Compison of diffnt mthods fo dlintion of 8F-FDG PET-positiv tissu fo tgt volum dfinition in diothpy of ptints ith non-smll cll lung cnc. J Nucl Md 5; 46: Hicks J, McMnus MP. 8F-FDG PET in cndidts fo dition thpy: is it impotnt nd ho do vlidt its impct? J Nucl Md 3;44:3. 67 Choi JY, Jng HJ, Shim YM, t l. 8F-FDG PET in ptints ith sophgl squmous cll ccinom undgoing cutiv sugy: pognostic implictions. J Nucl Md 4;45: Nton M, Austin MC, Chn JG, McKy WJ, o CC, Bkovic SF. Ictl SPECT Using Tchntium-99m-HMPAO: Mthods fo pid Pption nd Optiml Dploymnt of Tc Duing Spontnous Sizus. J Nucl Md 993;34: O Bin TJ, O Conno MK, Mulln BP, Binkmnn BH, Hnson D, Jck C, So EL. Subtction ictl SPET co-gistd to MI in ptil pilpsy: dsciption nd tchnicl vlidtion of th mthod ith phntom nd ptint studis. Nucl Md Commun 998;9: Ntionl Elcticl Mnufctus Assocition. Digitl Imging nd Communictions in Mdicin (DICOM) 3. Vigini, USA: Ntionl Elcticl Mnufctus Assocition, 3. 7 dionics. Xknif T Scnning Mnul, (fo soft vsion.). Bulington MA: dionics, 3. 7 Univsity Hospitl of Gnv [hompg on th Intnt]. Gnv: Univsity Hospitl of Gnv; [citd Oct 9 th ]. Avilbl fom: 73 Ntionl Elcticl Mnufctus Assocition. Digitl Imging nd Communictions in Mdicin (DICOM) 3 Pt 3 Mdi Stog nd Fil Fomt fo Mdi Intchng. Vigini, USA: Ntionl Elcticl Mnufctus Assocition, Hilbun MP, obts TS, Apuzzo MLJ, Wlls TH, Sbshin JK. Pliminy xpinc ith Bon-obt-Wlls (BW) computizd tomogphy stotctic guidnc systm. J Nuosug 983;59: Hill DLG, Hks DJ, Cossmn JE, t l. gisttion of M nd CT imgs fo skull bs sugy using point-lik ntomicl ftus. B J diol 99;64: Ppvsiliou P, Flux GD, Flo MA, Guy MJ. An utomtd tchniqu fo SPECT mkbsd img gisttion in dionuclid thpy. Phys Md Biol ;46: Mdicl Connctions [hompg on th intnt]. Sns, Unitd Kingdom: Mdicl Connctions; [citd Oct 9]. Avilbl fom.mdiclconnctions.co.uk. 78 Knighn BW, itchi DM. Th C pogmming lngug. nd dn. Englood Cliffs, N Jsy: Pntic Hll, Holdstock JS, Mys A, Isc CL, Gong Q, obts N. Diffntil involvmnt of th hippocmpus nd tmpol lob cotics in pid nd slo lning of n smntic infomtion. Nuopsychoi ;4:

76 Chpt : Plud (fncs) 8 Block I, O Ly DS, Hich D, t l. Effcts of fqunt mijun us on mmoy-ltd gionl cbl blood flo. Phmcol Biochm Bhv, ;7: OFFIS Institut [hompg on th intnt]. Oldnbug, Gmny: OFFIS Institut; [citd Oct 9]. Avilbl fom 8 Ackly T, Gso M, Smith. diothpy DICOM pckt sniffing. Austls Phys Eng Sci Md 8;3: Ackly T, Lncst CM, oxby KJ, Gso M. Clinicl ccucy of ExcTc intcnil fmlss stotctic systm Md Phys ;38:

77 Chpt : Sgmnting tumous fom functionl imging Chpt Sgmnting tumous fom functionl imging. Hving bn th discov of mny splndid things, h is sid to hv skd his finds nd ltions tht, ft his dth, thy should plc on his tomb cylind nclosing sph, iting on it th popotion of th contining solid to tht hich is contind. Plutch: Lif of Mcllus Contnts. SEGMENTING TUMOUS FOM FUNCTIONAL IMAGING DOCUMENTED SEGMENTATION METHODS A EVIEW OF THE ELATIVE THESHOLD METHOD (EDI S METHOD) Vlidtions of Edi s mthod Ovvis of imging in diothpy potd clinicl pplictions of Edi s mthod Sgmnttion Mthods: Oth sgmnttion modls Sgmnttion chckd ginst pthoy Plnning Studis Phntom chctiztion of Movmnt Qulittiv ok Ubiquity EDI S THESHOLD METHOD HYPOTHESES QUALITATIVE EXPLANATION OF EDI S ESULTS QUANTITATIVE MODELLING OF EDI S ESULTS Appoximting disct function ith continuous on Using qution.5- to obtin Edi s thshold sults Minimum thshold Fitting to Edi s dt Clcultion of siduls Sptil solution stimts Exponntil pmtiztion of thshold tio Possibl sons tht th modl dos not fit Img voxl siz DEIVING THE ADIAL EQUATION Th dil qution t th cnt nd piphy of sph ltiv dil qution Img voxlistion BLACKS EQUATION Intgting th dil qution Blck s thshold Clcultion of siduls sons fo gdint discpncy ith Blcks qution Bckgound ffct on th gdint vlu in Blcks modl

78 Chpt : Sgmnting tumous fom functionl imging.7.6 Limittion of Blcks mthod Thsholds fo sphicl shll tumou sults of pplying Blck s thshold to sphicl shll....8 EXPEIMENTAL TEST OF THE ADIAL EQUATION Intfcing PET-CT imgs into th TPS PET Img nlysis tools fo th TPS Algoithm to tst th dil qution Finding th cnt of sph Tsting th dil qution on cc sph Nois nd sgmnttion Estimting th ffct of nois on Edi s sults NOISE PIXELATION DE-COELATION BY MONTE CALO INTEGATION.... 3D PET SPHEE EXPEIMENT Edi thsholds Blck thsholds dil ltion Nois stimtion.... BAMBILLAS EQUATIONS:.... CLINICAL ELEVANCE..... Envisiond implmnttion CONCLUSION Sgmnting tumous fom functionl imging Th is no gnl consnsus on th mthod tht should b follod hn sgmnting tumou volums using functionl imging. Fo this son, dsciption of th pticul sgmnttion mthod oftn foms lg pt of ny study vluting th us of PET imgs in diothpy ttmnt plnning. In sctions.6.4 nd.7.3 xmpls of such img sgmnttion mthods hv bn psntd. This chpt bgins ith n cknoldgmnt of th clinicl contovsy ov th lvl of humn input into tumou sgmnttion ith functionl imging. Th focus thn nos to th fist documntd nd cliniclly most idly implmntd sgmnttion mthod, th ltiv thshold mthod. Th impct of this mthod is stblishd by vi of th ssocitd littu, nging fom phntom studis to diffnt clinicl sits. Th is in th littu no modl to xplin th pdictions of th ltiv thshold mthod fo -D PET, so qulittiv modl is dvlopd nd find into n xtndbl quntittiv thoy. Th limittions of this modl dmonsttd by pplying it to 3D-PET. Th chpt concluds ith considtion of th clinicl qustion tht th thoy nss.. Documntd Sgmnttion mthods. Any dsciption of sgmnttion mthods ould b incomplt if it did not bgin ith n cknoldgmnt tht th is contovsy ov hth such mthods should b documntd. Poponnts of documnttion such s Lvnkov t l. dvoct fo clly stblishd mthodoy of pimy GTV dfinition in NSCLC using thsholding tchniqus. In contst, McMnus nd Hicks dvoctd ginst utomtd mthods nd fo flxibility in tgt volum dfinition potocols to llo fo th incopotion of oth infomtion. Thy pointd out tht Fully utomtd contouing cn somtims b % poducibl but % ong. Th middl y btn ths to polizd outlooks sks to incopot clinicl judgmnt nd utomtd mthods. A simil collbotiv goup xtndd this thshold mthod to dl ith bckgound nd non tumou PET vid stuctus 3. 56

79 Chpt : Sgmnting tumous fom functionl imging Clinicl studis documnt mny diffnt mthods to sgmnt tumou volums fom PET imgs. Som mthods simply not spcifid, th tgt volum is simply dscibd s bing lft to bod ctifid dioists 4. Som mthods ly on n SUV tio, hich is th tio to th signl xpctd givn th ptint s hight, ight, nd th mount of injctd FDG 5. Som mthods ly on intnsity ltiv to physioicl PET intnsity, so fo xmpl th blood pool in th ot 6. Som mthods intoduc constints on th xpctd siz o shp of th sgmntd volum to constin sgmnttion, so fo xmpl though th us of snks 7. Amongst ll of ths mthods, th on tht hs bn implmntd most idly, documntd th most nd yt on of th simplst mthods, is th ltiv thshold mthod.. A vi of th ltiv thshold mthod (Edi s mthod) Th ltiv thshold mthod is vy simpl sgmnttion mthod tht cn b sily implmntd ithin diothpy ttmnt plnning systm. All PET img voxls ith gyscl vlu high thn fixd thshold sgmntd s pt of th tumou. Th thshold is pcntg of th mximum PET pixl vlu ithin th tumou, hich cn in gnl b volum dpndnt. Edi t l obtind ths thsholds by imging sphs of knon volum, nd thn pplid ths thsholds to sgmnt tumous of cosponding volum but bity shp 8. Th ov fncs tht cit this oiginl ok by Edi 8. A vi of this body of littu is phps th bst y to dmonstt th bdth of th impct of this mthod... Vlidtions of Edi s mthod Som of th littu is bst clssifid s indpndnt vlidtions of th oiginl xpimntl ok. Asid fom confiming th vlidity of th oiginl ok, som of thm contin dditionl insights on th pplicbility of th mthod. Ymko t l. 9 ssntilly vlidtd Edi s thshold msumnts on diffnt PET unit (C-PET, Philips-ADAC Mdicl Systms, Milpits, CA, USA). Thy obsvd th incs of thshold ith dcsing volum, nd postultd sptil solution nd nois s th likly son. An xtnsion of this postult undpins to of th th hypothss of this chpt in sction.3. Wng t l. usd Edi s thshold mthod to obtin volums of pooly diffntitd thyoid lsions. Thy thn shod tht th volums obtind th singl stongst pdicto of suvivl. Sgouos t l. f to Edi s thshold mthod ging ith volums thy hv stimtd indpndntly by combintion of singl photon mission pln imging nd CT scn sgmnttion of th spln lodd ith 3Bi. Thy us ths volums to stimt th dos fom th lph mitting isotop fo ptints ith Lukmi. Nhmh t l. usd Edi s thshold mthod to dtmin volums fom PET imgs of oscillting FDG lodd phntoms, ith nd ithout gting s mthod of dtmining th ffctivnss of th gting coctions. A simil goup 3 nt on to vlut spitoy gtd (4-D) PET/CT imging of th thox, using cntoids of volums sgmntd using Edi s thshold mthod. Cldll 4 t l usd Edi s mthod to sgmnt volums fom ungtd PET imgs of moving FDG lodd phntoms. Thy found tht ths volums ncpsultd th phntom nd its movmnt. 57

80 Chpt : Sgmnting tumous fom functionl imging.. Ovvis of imging in diothpy In gnlizd vi of imging in diothpy 5 tht fncs Edi s thshold mthod, vibl ffct of thsholds o oth citi usd to dfin tumou mgins is givn s dbck of PET imging. In vi of tgtd molcul imging fo diothpy, Nimmgdd t l. 6 gin idntify Edi s thshold mthod, nd th lck of obust sgmnttion mthod du to n unctinty bout th tumou thshold, s bing n impdimnt to th us of PET fo tumou volum mking...3 potd clinicl pplictions of Edi s mthod In 5 lung cnc pilot study, Jitt t l. 7 ould not modify thi ttmnt plns bsd on PET GTVs bcus of th unctinty thy hd bout th vlidity of Edi s thshold mthod mong oths. Mmd t l. 8 in pfnc to Edi s mthod, usd thshold bsd on lvl stndd dvitions bov bckgound, nd usd ths volums to xplo th usfulnss of PET-CT in ssssing th spons to ttmnt of sophgl cnc. Fod t l. 9 notd in plnning study of hd nd nck lsions tht th thsholds of Edi s mthod dpndnt on th constuction mthod usd. El-Bssiouni t l. sought to dfin th bst thshold fo PET significnc in hd nd nck cnc fo tumou volum mking by dtmining th thshold lvl tht bst mtchd th volum dtmind by CT lon. Additionlly, thy usd fiducil bsd img fusion offst of up to mm. Th ky obsvtion s tht singl thshold vlu could not b usd. Edi s thshold mthod s slf fncd by Fox t l. ho usd it to sgmnt NSCLC GTVs fom PET imgs s th undpinning of study of th ffct of PET on tumou volum vibility. Hong t l. compd Edi s thshold ith CT bsd sgmnttion nd SUV >.5 sgmnttion fo NSCLC in plnning study, nd commndd SUV >.5 fo NSCLC bcus of tumou htognity. Edi s thshold mthod s usd by Su t l. 3 to sgmnt volums of post diothpy cunc s pt of n ssssmnt of locl filu. McDmott t l. 4 usd Edi s thshold mthod to monito th chng in volum of PET imgs of pimy bst tumous duing chmothpy. Edi s thshold mthod hs bn usd s th PET volum sgmnttion mthod in study on ptints of Thyoid Cnc Thpy 3I intnl dosimty 5. Song t l. 6 usd Edi s thshold mthod to dtmin th volum nd thus clcult th dos fo dioiodin ttmnt of diffus lung mtstss. V t l. 7 usd Edi s thshold mthod to sgmnt PET gions of intst (OIs) s pt of dtmintion tht th us of contst nhncd CT fo ttnution coction hs no significnt ffct on quntifiction of FDG uptk fo Lymphom (Hodkin s diss nd Non-Hodgkins Lymphom). Edi s thshold mthod s usd to dtmin Non-Hodgkins Lymphom volums, fom hich th intnsity of indolnt nd ggssiv sub popultions s compd 8. But t l. 9 usd Edi s thshold mthod to dtmin tumou volums fom PET studis of humn coloctl cnc cll lins xnogftd into ts. Cinik t l. 3 fnc Edi s thshold mthod in suppot of positiv vlution of utomtd thshold bsd sgmnttion of ctl cnc GTVs. Bssi t l. 3 usd Edi s thshold mthod to sgmnt PET GTVs in compison to GTVs sgmntd fom CT dt, hich shod 5% incs in GTV volum if PET s usd. Lboullux t l. 3 usd Edi s thshold mthod to dtmin tumou volums to vlut PET imging fo dignosis nd pognosis of dnocoticl ccinom. 58

81 Chpt : Sgmnting tumous fom functionl imging..4 Sgmnttion Mthods: Oth sgmnttion modls. Edi s thshold mthod ts only pssing mntion s n ppliction fo img sgmnttion in Boud nd Zidi s dtild thoticl vi 33 of img sgmnttion tchniqus in Nucl Mdicin imging. Topics covd includ thsholding, gion going, clssifis, clusting-bsd, dg dtction, dg thsholding, mkov ndom fild modls, tificil nul ntoks, dfombl modls, tls guidd ppochs, nd nlysis of tim ctivity cuvs. Edi s thsholding mthod is oftn citd by goups poposing oth modls. Fo xmpl Disn t l. 34 comp thi on PET volum sgmnttion ith Edi s Thshold mthod. Thy incoctly pot Edi s mthod s quiing pioi knoldg of th volum. This pp s incopotd by Disn 35 s chpt in his thsis. Blck t l. 36 cit Edi s mthod to comp ith thi on sgmnttion mthod. Blck usd th vg ctivity ithin th sgmntd volum, th thn th mximum ctivity tht Edi usd, to dtmin th thshold. This mthod is vid nd contstd to Edi s mthod in sction.7. Bdijk t l. 37 vid th sttus of FDG-PET in tumou volum dfinition in diothpy ttmnt plnning nd obsvd Only f studis us utomtic sgmnttion, bsd on ctin intnsity lvl, such s SUV-lvl, pcntg of th mximl SUV o th souc to bckgound tio. Aistophnous t l. 38 poposd gussin mixtu modl, hich Boud nd Zidi 33 clssify s n unsupvisd clusting bsd ppoch using th xpcttion mximiztion lgoithm. Th min disdvntg of clusting is tht th ppopit numb of clusts must b dcidd bfo hnd. In this cs th clusts usd, lbld s tumou, bckgound, nd unctin, on th bsis of vi of th img intnsity histogm. It is not cl if this numb of clusts ould in gnl b th coct choic. Jitt t l. 39 obsvd tht thsholding is th most idly usd mthod to dtmin volums utomticlly fom PET imgs. Nstl t l. 4 found tht fo FDG positiv mdistinl lymph nods, th utomtic sgmnttion mthod usd did not mtt: ll poducd volums tht cliniclly th sm. Htt t l. 4 pply fuzzy hiddn mkov chins fo sgmnttion of PET volums. Th mthod is mo complx thn thsholding, but is compd ginst fixd thsholding th thn th dptiv thsholding of Edi s mthod. This ok is tht it is just s impotnt to gt th ight volum s it is to gt th volum in th ight plc. Thy thfo compd th totl clssifiction os, positiv nd ngtiv, th thn volum os. Positiv clssifiction os bckgound voxls tht incoctly clssifid s blonging to th tumou. Ngtiv clssifiction os tumou voxls tht incoctly clssifid s blonging to th bckgound. Th fixd thsholds btt t lg sphs ith high signl to nois tio, but much os fo smll volums t lo signl to nois tios. Th coct thshold should hv qul numb of NCEs nd PCEs (Ngtiv 59

82 Chpt : Sgmnting tumous fom functionl imging clssifiction os nd positiv clssifiction os). 4% is nominl thshold fo lg sphs t high signl to nois tios. It is knon tht th thshold must b incsd fo vy smll volums, nd is ppoximtly 4% fo vy lg volums, but dcss in btn. So th thshold nds to b lo fo smll sphs. As th thshold usd is too high fo ths sphs, ll of th tumou is includd (no NCEs) nd mny pixls incoctly pomotd fom bckgound to tumou. It is lso knon tht th thshold dpnds on th signl to nois tio. Pdictbly, PCEs sponsibl fo ll of th os. Th conclusion psntd by th pp, tht fuzzy hiddn mkov chins sgmnt th volums btt thn thshold mthods, dos not pply to Edi s thshold mthod. Th concpt of NCEs nd PCEs is not sn lsh in th littu. It is usful cognition bcus in diothpy intstd in th coct positioning of th tumou s ll s gtting th volum ight, s ill xplo in chpt 4. This limittion is lso psnt in most histoicl studis, th is no coltion of position, only volum o mximl lin dimnsion. W ill s lt in sction.8 nd chpt 4 tht this considtion is impotnt in diothpy, nd tht th is limittion to th bility to th ccucy ith hich th cnt of sph cn b dtmind fom th PET img dt of th sph. Dv t l. 4 poposd locl contst mthod in hich th tumou s sgmntd indpndntly on ch slic of 3D volum, using thsholds tht vid ith coss sctionl nd slic position. Thy lso of th dius of cuvtu ffct, but thy hd too mny pmts to b pdictiv. Th sm goup follod up in 7 43 ith n ittiv slic spcific ittiv thshold tchniqu. Thy of th ffct of pixls fo smll volums, nd thy lookd t som non sphicl phntoms. A thid pp by th sm goup 44 compd th of th mthods idntifid by Boud nd Zidi 33 ; thsholding, Sobl dg dtction, nd th tshd ppoch. Thy found fom phntom studis tht only th thshold tchniqu could ccutly dtmin phntom volums, but tht th thshold s volum dpndnt. Th thsholding tchniqu tht thy usd s diffnt fom Edi s in tht thy usd coss sction thshold mthod, th thn th 3D mthod usd by Edi. Sobl dg dtction is subst of dg dtction mthods. Sinc dgs locl ftus, diffntil optos usd in dg dtction, such s th obts gdint, Sobl gdint, Pitt gdint nd th lplcin opto. Th sobl msk optos usd in this cicumstnc nd fo hoizontl nd vticl dgs spctivly. Th tshd lgoithm in this cs cts on th gdint vcto fild of th img, gos gions ound th locl minim until thy mt oth gions, nd uss th boundis s closd contous tht sgmnt th img. Th lgoithm is knon to ov sgmnt noisy imgs 45 hich th uthos ttmptd to void by mk slction. Jntzn t l. 46 usd Edi s thshold mthod, but ithout ny initil stimt of th volum of th tumou. Thy clld thi mthod th ittiv thshold mthod (ITM). Thy obsvd Th publishd thsholding mthods 6

83 Chpt : Sgmnting tumous fom functionl imging povid libl stimts only if th img ctivity distibution is homognous. Thy found lg dvitions fo volums lss thn.5 ml. Fo volums lg thn. ml, thy got % vition. Montgomy t l. 47 idntify tht th min limittion of Edi s thshold mthod is tht th sults coupld too tightly ith th thsholds usd, h ny chng cn compltly lt th sults of th sgmnttion. Thy popos th us of Mkov ndom fild modl, in hich voxl is in o out of th gion dpnding only on its vlu nd tht of its immdit nighbous. El Nq t l. 48 fnc Edi s thshold mthod s n xmpl of sgmnttion mthod tht uss only singl modlity, s n intoduction to thi pliminy invstigtion of poposd mthod of sgmnttion bsd on PET nd CT infomtion. Bmbill t l. 49 fncd Edi s mthod s n intoduction to dtmintion of th thshold fom phntom obsvtions hich dpndd on th tgt to bckgound tio, th sph dimt, th scn dution nd th ctivity. Thy split th mtch into to distinct s bov nd blo cm dimt. Thy limintd scn dution nd injctd ctivity s pmts of significnc. So thy lft ith just th dimt nd tgt to bckgound tio. W vi thi mthod in sction....5 Sgmnttion chckd ginst pthoy Th finl tst of sgmnttion mthod is by dict pthoicl dtmintion. Bdijk t l. 5 obsvd good coltion btn uto-dlintd contous nd pthoicl sizs...6 Plnning Studis Chtty t l. 5 xmind th ffct of vying th thshold usd in Edi s thsholding mthod on th dos to th tumou nd to noml tissu (lung) nd found tht it cn hv potntilly cliniclly significnt impct fo both. Gills t l. 5 did plnning study on NSCLC comping CT nd PET volums, nd tbultd th vitions in clinicl study mthods of tumou sgmnttion. Thy lso tbultd numb of ptints, hth ddictd CT-PET s usd, hth th s spt PET stging, ht tgt volum chngs obsvd, ht noml tissu DVH vlution s md, nd ho int-obsv vibility s vlutd. In gnl vi of th us of PET fo diothpy 53, Edi points out tht th SUV thshold mthod, h ll gions ith n SUV>.5 includd, hs bn vlidtd fo stging but not fo sgmnttion. H gos on to slf fnc his on thshold mthod s th pfd solution...7 Phntom chctiztion of Movmnt Ymko t l. 54 sho fom phntom xpimnts tht coctly sgmnting moving volums quis thsholds lo thn thos usd by Edi s thshold mthod. Ngl t l. 55 usd thsholds stight fom Edi s mthod, but thy vgd th mximum coss bthing cycls, hich ould chng som of th ffct of nois. On th bsis of th clcultd volums, thy concludd tht ttnution mps fo ch spitoy phs s impotnt s 6

84 Chpt : Sgmnting tumous fom functionl imging mission gts fo coctly sgmnting volums. Bosmns 56 incopotd this ok s chpt in his thsis. Chi t l. 57 slf fncd Edi s thshold mthod to sgmnt tumou volum gions of intst to undpin dsign study of spition vgd CT fo ttnution coction of th PET dt fom PET/CT...8 Qulittiv ok Kk t l. 58 fnc Edi s thshold mthod in pssing s hving th dvntg of bing bl to ssss mtbolic tumou volum. Thi min mphsis s on quntittiv ok, th thn tumou sgmnttion. Schod t l. 59 slf fnc Edi s thshold mthod s infoming thi choic of FDG phntom volum to void ptil volum ffct. This pp is lso impotnt in pointing out th influnc of constuction pmts on th clinicl intpttion of PET imgs. Hmill t l. 6 obsv th ffct of spition on quntittiv PET in th gion of th diphgm. Thy obsv tht ttnution dt must b mtchd in phs to th PET dt phs. Thy not in pssing th implictions fo thsholding tchniqus such s Edi s, tht thy cnnot b pplid ccutly ithout such dt. Biolo-iding t l. 6 suggst vging th SUV ov volums dfind by Edi s thshold mthod s y of impoving th pdictiv vlu of duction in SUV by no-djuvnt chmothpy in bst cnc...9 Ubiquity Th to mjo sons tht Edi s mthod is so idly fd to in th clinicl contxt tht it is simpl nd sy to implmnt. Any diothpy ttmnt plnning systm llos th implmnttion of Edi s mthod ithout ny modifiction of th soft. Th mthod povids simpl ns to complx poblm, voxl is sgmntd s pt of th tumou if th PET img vlu is bov th thshold givn by Edi..3 Edi s thshold mthod hypothss Th hypothss poposd ith spct to Edi s thshold mthod. Fistly, tht qulittiv xplntion fo th thshold bhviou obsvd cn b obtind by tting th img s n idlizd continuous function nd modling th -D PET imging pocss s simpl Gussin bluing. Scondly, tht by intoducing nois ppoximtion s ptubtion, it is possibl to obtin quntittiv modl to pdict th thsholds of Edi s mthod fo -D PET fom th sptil solution nd nois chctistics of th scnn. Thidly, th sm modl cn b usd to d pllls btn divs thshold mthods poposd by invstigtos, ith som limitd lvnc vn to 3-D PET..4 QUALITATIVE EXPLANATION OF EDI S ESULTS Th qulittiv xplntion fo th thshold bhvio obsvd by Edi, h s th volum of th sph dcss, th thshold dops fom 5% nd thn iss gin to mo thn 5%, cn b xplind by th intction of th sptil bluing on th img of th cnt of th sph, nd th ffct of th cuvtu of th sufc of th sph. 6

85 Chpt : Sgmnting tumous fom functionl imging Fo vy lg sphs, th sufc is ffctivly flt, nd th ffct of sptil bluing on th mgnitud of th mximum imgd concnttion t th cnt of th sph is ngligibl. Nith fcto impcts so th thshold is 5%. Fo intmdit siz sphs, th cuvtu t th sufc of th sph bcoms significnt, hil th ffct of sptil bluing t th cnt of th sph is still ngligibl. Sptil bluing t th sufc of th sph mns tht th imgd concnttion is ightd sum of th concnttions in th immdit vicinity, s th sufc cuvtu bcoms significnt, mo thn hlf th points in th immdit vicinity hv zo concnttion (Figu.4-). Fig..4- As th cuvtu of th sufc of th sph (d lin) incss ltiv to th FWHM (dimt of gn cicl), th numb of points in th immdit vicinity of point on th piphy of th sph (smll blck cicl) tht ithin th sph diminishs blo hlf. A hoizontl dimt hs bn dn (blck lin) to illustt this. Fo vy smll sphs, h th dius of th sph is smll compd ith th full idth t hlf mximum (FWHM), th bluing bgins to ffct th mgnitud of th signl t th cnt of th sph, hich incss th thshold. Th thshold iss bov 5% hn th gomticl ffct of sufc cuvtu is ovcom by th xponntil dcs of signl fom th cnt of th sph du to th sptil bluing..5 QUANTITATIVE MODELLING OF EDI S ESULTS. To dtmin th mgnitud of ths ffcts quntittivly, th sptil distibution of th concnttion of FDG ithin sphicl phntom filld ith FDG of concnttion C ithin th sph, nd zo outsid th sph, cn b dscibd in n idlisd mthmticl fom by ctngul function. Using sphicl pol coodints ith th oigin t th cnt of th sph, th distibution of concnttion P (,φ,θ ) is givn by th qution P C φ Eqution.5- > (,, θ ) h C is th concnttion of FDG ithin th sph in units of Bq/ml. is th dius of th sph in units of cm P is continuous function dscibing th concnttion of FDG t ny point. 63

86 Chpt : Sgmnting tumous fom functionl imging By hypothsis th imging pocss cn b dscibd puly s Gussin convolution, nd th img of th concnttion of dioctiv isotop, I (,φ,θ ) is continuous function givn by convolution intgl (, φ, θ ) P(, φ, θ ) g( ) sin( θ ) I dθ dφ d Eqution.5- h is vcto fom th oigin to th point dscibd by th sphicl pol coodints, φ, θ. is vcto fom th oigin to th point dscibd by th sphicl pol coodints, φ, θ. g ( ) is 3-D gussin spd function, ith FWHM of in cm. Th fom of th gussin spd function is thn g ( ) g k A Eqution.5-3 Sinc th vlu of th FWHM is in units of cm, hv ( / ) g k 4 g Eqution.5-4 Which implis tht 4 k Eqution.5-5 Nomlistion of th gussin spd function lso quis tht () sin() φ g dθdφd Eqution.5-6 Sinc th gussin spd function is function of only, nd ( φ ) sin d φ Eqution.5-7 s ll s th tivil vlution d θ Eqution.5-8 So qution.5-6 bcoms () d 4 g Eqution.5-9 This intgl cn b solvd by intgting by pts dv du U d UV V d d Eqution.5- d Using th substitution U Eqution.5- nd 64

87 k Chpt : Sgmnting tumous fom functionl imging V k Eqution.5- so tht du d nd dv d k Eqution.5-3 Eqution.5-4 So tht qution.5-9 bcoms 4 A k 4A d k k 4A k k Th dfinit intgl of gussin ov this ng is knon d A d k k d Eqution.5-5 Eqution.5-6 So hv A k d A k k k k Which llos us to vlut th constnt A k A Eqution.5-7 Eqution Appoximting disct function ith continuous on. Th img fom PET scnn is voxlisd img, but qution.5- csts it, by hypothsis, s continuous function. So in ddition to idlizing th imging pocss, qution.5- lso dls ith n idlizd img. Th impct of ths to idlistions must b considd hn vluting ny conclusion chd fom vluting qution.5-. (S sction.6.3 Img voxlistion).5. Using qution.5- to obtin Edi s thshold sults. Th thshold quid to sgmnt th sph dpnds on th img t th sufc of th sph nd th mximum ithin th img, hich in th idlisd modl ill lys b t th cnt of th sph. So th thshold to sgmnt th sph is I(,,) λ Eqution.5.- I(,,) h I (,,) is th mximum vlu ithin th img, t th cnt of th sph of dius 65

88 I(,,) is th vlu of th img t th sufc of th sph. λ is th thshold tio quid to sgmnt th sph. Chpt : Sgmnting tumous fom functionl imging To sgmnt th sph, ll points ith n img vlu gt thn o qul to λ tims th mximum includd, ll thos ith lo vlu xcludd. Th thshold pcntg is obtind by multiplying th thshold tio by. To obtin λ, must vlut th numto nd dnominto of qution.5.-. (,,) P(, φ, θ ) g( ) sin( θ ) I dθ dφ d Eqution.5.- Sinc fom qution, P (,φ,θ ) is zo hn > ; I k (,,) C g( ) sin( θ ) dθ dφ d 4C A d Eqution.5.-3 Intgting by pts nd substituting U nd V s bfo in qutions.5- to.5-4 yilds I I 4C k k k k (,,) 4 C A d 4C A d k C k k k (,,) 4 C A d 4C A d k A A k Eqution.5.-4 Eqution.5.-5 Th intgl in qution.5.-5 cnnot b vlutd nlyticlly, but it cn b xpssd in tms of tbultd functions, such s th f function fom MATLAB o th NOMSDIST function fom xcl. f x t ( x) dt Eqution.5.-6 NOMSDIST I z t ( z) dt dt.5 C A k (,,) C A f ( k ) k k o substituting out k nd A fom qution.5-5 nd.5-8 spctivly, I (,,) 4 4 C C z t f To us NOMSDIST, mk us of th vlu of NOMSDIST().5 Eqution.5.-7 Eqution.5.-8 Eqution

89 I.5 C A k C A (,,) ( NOMSDIST ( k ).5). 5 k k 4 4 I,, C C NOMSDIST Chpt : Sgmnting tumous fom functionl imging Eqution Eqution It is cl by inspction of qution.5.-9 o.5.- tht I (,,) is function only of th tio, th dius of th sph to th FWHM of th scnn. This qution is gphd in Figu.5.-. Sinc th FWHM vis fom scnn to scnn, this qution is gphd ith ithmic x xis, so tht th bsic shp of th gph ill b invint ith FWHM. A chng in th FWHM of th scnn ill only mov th gph to th lft o ight, ithout chnging th shp, on ithmic scl. Fom Figu.5.- it cn b sn tht onc th dius of th sph incss to tic th FWHM, I (,,) is ffctivly constnt. Th xtpoltion to smll vlus of pdictd by th modl is not coct in pctic, bcus t som point th volum of th sph bcoms smll thn th voxl volum. In pctic such smll sphs vntully cnnot b solvd fom bckgound signl. Fig..5.- This figu is -lin plot of th img vlu t th cnt of th sph ginst th tio of th dius of th sph to th full idth t hlf mximum sptil solution of th imging pocss. Th ltionship is obtind by considing th imging pocss s puly Gussin bluing. No th dnominto of qution.5.- is vlutd (,,) P(, φ, θ ) g( ) sin( θ ) I dθ dφ d Eqution.5.- h (,,) is ny point on th sufc of th sph of dius. Fom th digm it is cl tht lthough th spd function hs sphicl symmty, th intgtion hs cylindicl symmty. Th qution is thfo cst in tms of cylindicl pol coodints. (Figu.5.-) 67

90 Chpt : Sgmnting tumous fom functionl imging Fig..5.- Cylindicl pol coodints. A cylindicl coodint systm ith oigin O, pol xis A, nd longitudinl xis L. Th dot is th point ith dil distnc ρ 4, ngul coodint φ 3, nd hight z 4. I z k ρ ( z) (,) C A ρdzdϕdρ, Eqution.5.-3 Sinc th intgl hs cylindicl symmty, this bcoms I I k ρ ( z) (,) C A z ρdzdρ, Eqution.5.-4 k ( z) (,) C A kρ, dz ρdρ Eqution.5.-5 z Substituting u kρ ; ρ dρ du ; u ρ z u k z ; k k ( z ) k ( z) u I(,,) C A dz du k Eqution.5.-6 ρ ; I I C A k dz k ( z) k ( ) ( z,, ).5 k t C A 4k (,,) AC dt ( ) k fom qution.5-8 I k k t C 4k (,,) C dt ( ) k Eqution.5.-7 Eqution.5.-8 Eqution

91 Chpt : Sgmnting tumous fom functionl imging 69 fom qution ,, t C dt C I Eqution ,, t C dt C I Eqution ,, C f C I Eqution ,, C NOMSDIST C I Eqution.5.-3 Agin it is cl by inspction of qution.5.- o.5.-3 tht,, I is function only of th tio, th dius of th sph to th FWHM of th scnn. This qution is gphd in Figu Agin sinc th FWHM vis fom scnn to scnn, this qution is gphd ith ithmic x xis, so tht th bsic shp of th gph ill b invint ith FWHM. A chng in th FWHM of th scnn ill only mov th gph to th lft o ight, ithout chnging th shp, on ithmic scl. Fom figu.5.-3 it cn b sn tht onc th dius of th sph is tims th FWHM,,, I is ffctivly constnt t vlu of.5. Th xtpoltion to smll vlus of pdictd by th modl is not coct in pctic, bcus t som point th dimt of th sph bcoms smll thn th voxl siz. At tht point th sufc of th sph nd th cnt of th sph cn both b ithin th sm voxl. In pctic such smll sphs vntully cnnot b solvd fom bckgound signl.

92 Chpt : Sgmnting tumous fom functionl imging Fig.5.-3 This figu is -lin plot of th img vlu t th sufc of th sph ginst th tio of th dius of th sph to th full idth t hlf mximum sptil solution of th imging pocss. This ltionship is divd on th bsis tht th imging pocss is Gussin bluing. No tht th numto nd dnominto of qution.5.- hv bn dtmind, cn gph th thshold quid to sgmnt th sph. Sinc th numto nd dnominto both functions only of th tio, it follos tht th thshold dpnds only on tht tio. Th thshold is gphd in Figu It cn b sn tht fo lg sphs, th thshold symptots fom blo to vlu of.5. Th sufc of lg sph is ssntilly pln sufc, nd th intnsity t th cnt of th sph is fully stutd. As th dius of th sph gts smll, th sufc of th sph bcoms mo nd mo cuvd. Th fction of th volum in th immdit vicinity of point on th sufc tht is ithin th sph nd thfo contins ctivity tht cn b blud into th sufc point bgins to dcs blo.5. At ths intmdit sizs, th cnt of th sph is still stutd, nd dos not dcs. So gomticl fctos t th sufc cus dcs in th thshold. As th dius of th sph ducs futh, th cnt of th sph bcoms unstutd nd th imgd intnsity t th cnt of th sph bgins to dop. This incss th tio of th thshold. Fo vy smll sphs, hn th dimt is compbl to th FWHM, th hol volum of th sph cn contibut to th intnsity t both th sufc nd th cnt of th sph, nd th thshold iss bov.5 in consqunc. Th modl pdicts tht th thshold iss to fo sph siz ith dius on fiftith of th FWHM, but in pctic th quntizd ntu of th img mns tht t this point th sufc nd th cnt of th sph cn ll b contind ithin on voxl. 7

93 Chpt : Sgmnting tumous fom functionl imging Fig Thshold tio This figu is -lin plot of th thshold tio ginst th tio of th dius of th sph to th full idth t hlf mximum sptil solution of th imging pocss. Th ltionship is divd fom th ssumption tht th imging pocss is Gussin bluing..5.3 Minimum thshold It is cl fom figu.5.-4 tht th is minimum vlu of th thshold tio, no dtmin ht this is numiclly. Fom qution.5.-, it is cl tht th minimum thshold vlu ill b givn by dλ Eqution.5.3- ds h th vibl s is givn by s Th vlu of th minimum cn b found numiclly to b.376 t s. 6 This mns tht this modl cnnot pdict thshold vlu blo.376, gdlss of th siz of th sph o th FWHM of th imging pocss..5.4 Fitting to Edi s dt. Th pdictions of qution.5.- cn b compd ith th sults of Edi 8, ith th FWHM ttd s n optimizd pmt. Tbl.5.4- shos th dt tht Edi gphd in figu of th 997 pp. 7

94 Chpt : Sgmnting tumous fom functionl imging Tbl.5.4- Modlling of Edi thshold dt Volum (ml) dius (cm) Edi xpimntl thshold 7 (pu numb) FWHM.46 cm FWHM.5 cm FWHM.946 cm Edi Exponntil Pmt Fit Sum squ o Tbl.5.4- This tbl shos th vition of thshold tio ith sph volum dtmind xpimntlly by Edi 8 in 997 in column th. Th nxt th columns sho th pdictions fom th idlizd modl (Eqution.5.-) fo diffnt vlus of th FWHM. Th lst column sho th thsholds pdictd by Edi s xponntil cuv pmt mtch fom 997. If th FWHM is tkn to b pmt in fit of th qution fo λ (Eqution.5.-) gphd in figu.5.-3 to th msud thshold tios in tbl.5.4-, it is found tht th optiml mtch is fo FWHM of.946 cm. This optimiztion nds to b dtild, sinc th is compting locl minimum t FWHM of.46 cm. Figu.5.5- shos th vition of siduls ith FWHM. Sinc th fminsch function of MATLAB implmnts th simplx sch mthod 6 hich my only find locl minim, th globl minimum s found by but foc mthod of dtmining th sum of th squ of th siduls fo ch FWHM in stps of. cm. Th to minim of this lin sch usd to clcult th thshold vlus in column 4 nd 6 of tbl.5.4-, hdd FWHM.46 cm nd FWHM.946 cm. Ths cuvs gphd in Figu.5.7- nd.5.7- s th lins indictd s FWHM.946 cm nd FWHM.46 cm in th lgnd..5.5 Clcultion of siduls A sum squ o is listd in tbl.5.4- t th bottom of columns 4-7. Fo ch of th fiv volums, th diffnc btn th thshold tio pdictd by th modl (s shon in th tbl) nd th xpimntlly dtmind thshold tio (s shon in column th of tbl.5.4-) is clcultd. Thn ch diffnc is squd nd ll fiv squs summd to gt th sum squ o. To put this mthmticlly, if tk th cs of th FWHM.46 cm dt. Th clcultd thsholds λ { λ.46 λ.47 λ.48 λ.48 λ.48} Ci c C C3 C 4 C5 Whil th xpimntlly dtmind thsholds λ { λ.6 λ.44 λ.4 λ.38 λ.38} Ei E E E 3 E 4 E5 7

95 Chpt : Sgmnting tumous fom functionl imging And th sum squ o is thn givn by ss 5 i λ λ Eqution.5.5- Ci Ei Th sum squ o vition ith FWHM is gphd in Figu.5.5- to sho th psnc of to locl minim. Fig Vition of sidul fom fit to Edi dt. Th to locl minim in th fit of th idl modl to Edi s xpimntl dt, this figu shos th but foc dtmintion of th globl minimum..5.6 Sptil solution stimts Also, Edi s xpimntl sults fom pticul PET scnn (GE Advnc, GE Mdicl Systms, Miluk, WI), th sptil solution of hich hs bn chctizd by Dlgdo t. l 66, s follos: Tnsxil solution (FWHM) is 3.8 mm t th cnt nd incss to 5. mm tngntil nd 7.3 mm dil t cm. Avg xil solution dcss fom 4. mm FWHM t th cnt to 6.6 mm t cm. Sctt fction is 9.4% nd.% fo dict nd coss slics, spctivly. With spt out, th vg sctt fction is 34%. Totl systm snsitivity fo tu vnts (in kcps/(µci/cc)) is 3 ith spt in nd ith spt out. Ddtim losss of 5% cospond to dioctivity concnttion of 4.9 (.8) µci/cc nd tu vnt count t of 489 (48) kcps ith spt in (out). Nois-quivlnt count t (NEC) fo th systm s hol shos mximum of 6 (59) kcps t dioctivity concnttion of 4. (.65) µci/cc ith spt in (out). NEC is insnsitiv to chngs in lo gmm-ngy discimintion btn 5 35 kv. So ill us nominl 5 mm sptil solution s listic stimt. 9.4 mm FWHM is byond th lms of possibility. Th thsholds clcultd by qution.5.- shon in column 5 of tbl.5.4-, und th hding FWHM.5 cm nd gphd in fig.5.7- nd.5.7- s th lin indictd in th lgnd s FWHM.5cm..5.7 Exponntil pmtiztion of thshold tio. Edi fittd th function in qution.5.7- in th oiginl pp s pmtic fit to th dt, ( C Volum( ml) ) THESHOLD % A.xp. Eqution

96 Chpt : Sgmnting tumous fom functionl imging this ill b modifid slightly so tht th fit is to th ctul tio, th thn pcntg, s xpssd in qution ( C Volum( ml) ) λ EDI MATCH A. xp. Eqution.5.7- And hn th to pmts optimizd to fit th dt, th sult is qution λ EDI MATCH xp.95. Eqution Wh A.5577, C.95 ml - Th thsholds pdictd by Edi s xponntil modl (qution.5.7-3) displyd in column 7 of tbl.5.4-, und th hding Edi Exponntil Pmt Fit nd gphd in Figu.5.7- nd.5.7- s th lin indictd in th lgnd s A.5577 C.95. Fig Modlling of Edi Thshold tios Figu.5.7- shos th modlling of th sph thshold tio hn th bckgound is zo. Th blu stisks Edi s msud dt fo this cs th y vlus of th disct points th vlus tbultd in column to of tbl Th gn lin is obtind fom pmt mtch of th FWHM to th dt ith qution.5.-. Th mtch is vy good, ith sum of th squ of sidul o of.. This fits btt thn th xponntil function usd by Edi. Unfotuntly FWHM of 9.4 mm is gt thn ny msud in th littu. A mo listic FWHM of 5 mm is shon by th light blu lin, but dos not mtch nly s ll s Edi s xponntil fit o th optimizd FWHM of 9.4 mm. Th d lin shos th cuv pdictd by th modl if th FWHM is spcifid s.46 cm, locl minimum. Although th cuv is lmost constnt thoughout th gion of th xpimntl sults, nd in fct incss slightly ith dius h th xpimntl points dcs ith dius, it dos xplin 74

97 Chpt : Sgmnting tumous fom functionl imging gphiclly ho th locl minimum iss bcus th vlu is n to th vg xpimntl thshold. If th FWHM is incsd o dcsd, th modl pdiction ill mov y fom th vg thshold so th summd squd o ill incs, hnc th locl minimum. Fig Modlling of Edi Thshold tios ith ithmic x xis. Figu.5.7- shos th sm dt s figu.5.7-, but ith ithmic x xis. This is sufficint to nsu tht if ny chng in th FWHM pmt of th modl is md, th modl ill tin th sm shp of cuv, but shiftd to th ight o lft. This gin dmonstts ho th locl minimum t FWHM.946 cm xists. W hv poducd th shp of Edi s sults, but not th ctul vlus. Th only pmt of th modl is th full idth t hlf mximum, th sptil solution. Chnging th FWHM is lik multiplying th vibl s by constnt. Bcus hv ithmic scl, this ill only mov th cuv in th figu to th lft o ight, it ill not chng th shp of th cuv. This cn clly by comping th th FWHM cuvs. Although supio fit to th dt hs bn chivd ith FWHM s pmt, th vlu obtind fo th optiml FWHM is outsid ht could sonbly b xpctd..5.8 Possibl sons tht th modl dos not fit. Th pmt mtch is so good, nd th bst fit FWHM is ppoximtly tic th xpctd FWHM, tht it must b xplicitly considd hth th modl hs bn cst in tms of th hlf idth t hlf mximum in o, o if th figus fo sptil solution quotd in th littu ctully f to hlf idth t hlf mximum o, not FWHM. Th fist possibility cn b dismissd simply by viing qution.5-4, hich is vy dfinitly cst in tms of FWHM. Th scond possibility is discountd by cful ding fom Dlgdo t l

98 Chpt : Sgmnting tumous fom functionl imging Anoth possibility is tht th PET scnn in us, fo sons not knon to us, s not pfoming to spcifiction, nd so hd much os sptil solution. Hov s mntiond in sction.., th hv bn mny indpndnt vifictions of Edi s mthod ithout ny such discpncis bing notd. Anoth possibility is digitl fult; tht it s possibl tht somh in th disply chin tht th pixl dt hd bn gggtd, so tht on pixl psntd th vg of fou oths. This ould hv doubld th ffctiv sptil solution. This possibility is lso discountd by th multipl indpndnt vifictions of sction... Anoth possibility is dtcto stution, but th concnttion of -3μCi/mL tht Edi potd is blo th 5% ddtim thshold of 4.9μCi/mL fo D mod ith th spt in position. With th spt tctd, in 3D mod 5% ddtim occus t.8 μci/ml. Edi did not xplicitly pot hth th dt cquid in 3D o D mod. It is xpctd tht ddtim coctions ill in ny cs not significntly ptub th img in D mod 63. In 3D mod n ppoximtion to vlut th coctions quid is givn by Bdi nd Msdn 64, high fquncy tifcts cn ptub th img, but it is unlikly thy ould ptub it to such n xtnt, nd th mins s bfo th multipl indpndnt pts of th mthod to ccount fo..5.9 Img voxl siz. Anoth possibility is tht fo smll volum sphs, th disct voxliztion of th img confounds th continuous vibl ssumption. This ould xplin th bd mtch fo smll sphs but not fo lg ons. W ill vi this possibility in sction.6.3. Hving limintd th obvious cuss of th quntittiv discpncis sulting fom th idlizd modl, must look lsh to find missing fcto tht cn b incopotd into n nhncd modl to obtin quntittiv, pdictiv modl. Unfotuntly it is not immditly obvious, fom th dt hv, ht tht nhncmnt should b. Th bst y to dmonstt ht is missing ith th modl tuns out to b to us th idlizd modl to pdict th img pixl vlus t ll points ithin nd ithout th sph, th thn just t th cnt nd th sufc. Sinc in th idlizd modl pfct sphs ct imgs ith sphicl symmty, th img vlus dpnd only on th distnc fom th cnt of th sph. Th ltionship btn th img vlus nd th distnc fom th cnt of th sph pdictd by th idlizd modl is thus tmd th dil qution. Th oiginl motivtion fo dtmining th dil qution s s stpping ston to vluting th ffct of img voxl siz on th thshold..6 Diving th dil qution. To bgin to s hy th modl dos not fit, hy th modl is indqut, bgin by clculting th img vlu t point P, loctd t distnc fom th cnt of th sph. P my b outsid o insid th sph. I z k ρ ( z ) (,) C A ρdρdϕdz, Eqution.6- nd in mnn nous to tht fo qution.5.-3, com to 76

99 Chpt : Sgmnting tumous fom functionl imging 77 dz d A C I z z k ρ ρ ρ,, Eqution.6- dz d A C I z k z k ρ ρ ρ,, Eqution.6-3 Agin substituting s bfo fo qution.5.-5 Substituting u kρ ; du k d ρ ρ ; u ρ ; z k u z ρ ; W thn gt du k dz A C I z k u z k,, Eqution.6-4 [ ] dz k A C dz k A C I z z k z k,, Eqution.6-5 dz k A C dz k A C I kz k z k,, Eqution.6-6 In th fist intgl, substitut z k u, du k dz, k u z, k u z dz k A C du k k A C I kz k k k u,, Eqution.6-7 k k k k k u k k A C du k A C I.5,, Eqution.6-8 In th fist intgl, substitut t u, dt du k t k u, k t k u k k k k k t k k A C dt k A C I.5,, Eqution.6-9.5,, k k k k t k A C dt k AC I Eqution.6- clling gin qution k A

100 Chpt : Sgmnting tumous fom functionl imging 78 So,, k k k k t k C dt C I Eqution.6- clling gin qution k ,, t C dt C I Eqution ,, C f f C I Eqution ,, t C dt C I Eqution ,, C NOMSDIST NOMSDIST C I Eqution.6-5 So no s tht,, I is function of nd. W tm this ltionship th dil qution. W cn gph this fo spcifid sph dius nd FWHM s chngs fom zo to ny limit ithin o outsid th sph..6. Th dil qution t th cnt nd piphy of sph. Sinc th vlu tht th dil qution must tk t th sufc (qution.5.-) nd th cnt (qution.5.-9) of sph hs ldy bn divd, th dil qution should duc to th sm xpssion hn vlutd t

101 Chpt : Sgmnting tumous fom functionl imging 79 ths to points. To do this, th limit of th dil qution is tkn t th sufc nd th cnt of th sph s follos. In th limit th dil qution bcoms: ,, t C dt C I Eqution ,, t C dt C I Eqution ,, t C dt C I Eqution ,, t C dt C I Eqution.6.-4 And qution.6.-4 is idnticl to qution.5.-. Not hov tht th limit of th dil qution is much mo difficult lim,, t C dt C I Eqution.6.-5 Th fist tm is stight fod dt C dt C dt C t t t lim Eqution.6.-6 But th scond tm is mo difficult, so must vlut lim lim Eqution.6.-7

102 Chpt : Sgmnting tumous fom functionl imging lim lim Eqution.6.-8 At hich point cn pply L Hospitl s ul 65, tht th limit of fction h th numto nd dnominto both tnd to zo is givn by th limit of th divtiv of th numto ov th divtiv of th dniminto lim 8 lim Eqution lim Eqution.6.- so lim,, t C dt C I Eqution ,, t C dt C I Eqution.6.- f C C I 4,, 4 Eqution.6.-3 And qution.6.-3 is idnticl to qution So th dil qution fits th points t th cnt of th sph nd t th sufc of th sph, s xpctd..6. ltiv dil qution. If divid though by th intnsity t th cnt of th sph, obtin th ltiv dil function, nomlizd to unity t th cnt of th sph, n xmpl of hich is gphd in Figu.6.-.

103 Chpt : Sgmnting tumous fom functionl imging Fig..6.- Th ltiv dil function, dn in this cs fo dius of cm nd FWHM of cm..6.3 Img voxlistion. Th dil qution cn b usd to stimt th ffct of img voxlistion on th img vlu t th cnt of th sph. On th ssumption tht th voxl vlu is th vg of th continuous function ov th volum of voxl, cn stt I pixl h Z / Y / X / ( xc yc, zc) I dxdydz, Eqution.6.3- Z / Y / X / ( x xc) ( y yc) ( z zc ) Eqution.6.3- nd xc,yc,zc is th coodints of th tu cnt of th sph ltiv to th cnt of th voxl. Th point (xc,yc,zc) could b nyh ithin th voxl, but th minimum vlu of I pixl is hn xcx/, ycy/, zcz/; in tht cicumstnc th cnt of th sph is loctd t vtx of th voxl, nd in th idl modl th cnt of th sph ould compos 8 voxls ith qul img vlu. Th mximum vlu of I pixl is hn xc, yc, zc (Th cnt of th sph is loctd t th cnt of th voxl.) This intgl cnnot b don nlyticlly, so numic intgtion is sotd to. Th voxl siz is tkn s 4 mm (x) by 4 mm (y) by 4.5 mm (z). To find th minimum vlu of Ipixl, qution.6-3 is vgd ov th dimnsionl ctngul gid tht bks ch xis into spt vnly spcd gdtions tht xctly fit ithin voxl. To find th mximum vlu of Ipixl, qution.6-3 is vgd ov th dimnsionl ctngul gid tht bks ch xis of th positiv octnt of th voxl into spt vnly spcd gdtions. Th gid thus hs tic th lin dnsity of tht usd to clcult th minimum, th vg ov th positiv octnt is by symmty 8

104 Chpt : Sgmnting tumous fom functionl imging th vg ov th hol voxl. In both css, th sultnt vg must b dividd though by th vlu t th cnt of th sph, obtind by vluting qution.5.-9, to gt th vg of th ltiv dil function. Tbl.6.3- Modlling of Edi thshold dt including voxlistion Volum (ml) dius (cm) Thshold FWHM.65 FWHM.65 FWHM.65 Eo cm cm TOP cm BOT Tbl.6.3- Modlling of Edi thshold dt including voxlistion Volum (ml) dius (cm) Thshold FWHM.5 FWHM.5 FWHM.5 Eo cm cm TOP cm BOT Th sults of this clcultion shon in tbls.6.3- nd.6.3-, fo FWHM of.65 nd.5 cm spctivly. Fo th listic FWHM vlu of.5 cm, th only mismtch is fo th lg volum sphs. If llo th FWHM to b s lg s.65 cm, th is n ffctiv mtch. Th ng of thsholds givn is phps too lg fo th smll sphs. If intstd in distibution, it ould tnd stongly tods th vg. Th xtm vlus cn only b chd by point t th cnt o point t th vtx. Th ould b lg volum ssocitd ith th middl, nd this ould tnd to mn tht th sigm limit ould b clos. Additionlly, fo th smllst sphs, th finit voxl siz impcts on th vlu t th piphy s ll s tht t th cnt, nd th to ffcts my b coupld. This is good cndidt fo mont clo vlution, nd ill tun to this qustion lt in sction.9, but no tht hv th ltiv dil qution, in position to consid th sults obtind by Blck t l Blcks qution. Blck s mthod lis on thshold hich is th tio of th piphy img vlu to th vg img vlu ov th volum. Using th dil qution, cn dtmin th vg ov th volum nd thus dtmin th ltionship nlyticlly. 8

105 Chpt : Sgmnting tumous fom functionl imging Intgting th dil qution. Sinc th img vlu t th piphy of th sph is ldy knon (Eqution.5.-3), only th vg img vlu ov th volum of th sph, I, must b found to dtmin Blck s thshold. To find it, th dil qution (Eqution.6-3) is intgtd ov th volum of th sph. d I d d d I I,, 4 sin,, φ θ θ θ φ Eqution.7.- h,, I is givn by th dil qution (Eqution.6-3). So Tm d C Tm d C Tm d f C Tm d f C I Eqution.7.- Considing fist tm4 Substituting u ; u ; du d ; u ; u givs qution.7.-3; u u u udu C du C du u C d C Eqution.7.-3 Considing scondly tm3 Substituting u ; u ; du d ; u ; u givs qution.7.-4; u u u udu C du C du u C d C Eqution.7.-4 Combining th fist to tms givs qution.7.-5

106 Chpt : Sgmnting tumous fom functionl imging 84 u u u u u u udu du C udu du udu du C Eqution.7.-5 Thn must vlut th to tms u du 4 tm5 nd u udu 4 tm6 To vlut tm5, substitut u x ; dx du ; x u ; x u 4 to obtin qution.7.-6; f dx dx dx du x x x u Eqution.7.-6 To vlut tm6, substitut 4 u v ; dv udu 8 ; v u ; 6 v u to obtin qution.7.-7; v u dv udu Eqution.7.-7 So putting th tms 5 nd 6 togth givs nd substituting bck into qution.7.-5, givs qution u u f C udu du C Eqution.7.-8

107 Chpt : Sgmnting tumous fom functionl imging 85 Going bck to th vy fist to tms, fo tm, substitut x ; ; dx x d to obtin qution.7.-9 dx x f x C dx x f x C d f C Eqution.7.-9 Which cn b vlutd using th idntity givn by qution x x x f x dx x f x x x x Eqution.7.- No to vlut tm, substitut x ; ; dx x d to obtin qution.7.- dx x f x C dx x f x C d f C Eqution.7.- Which cn b vlutd using th idntity givn by qution x x x f x dx x f x x x Eqution.7.- So tht tm nd tm sum to giv f C d f C d f C Eqution.7.-3 h

108 Chpt : Sgmnting tumous fom functionl imging 86 So qution.7.- cn b ittn s qution.7.-4 f C f C I Eqution.7.-4 h Computtionlly, this is difficult to vlut, s fo lg vlus of nd smll vlus of ithin th clinicl ng, 4 cn ffctivly go to zo, nd 4 gos to infinity. So it qution.7.-4 s qution.7.-5 f C f C I Eqution.7.-5 To dtmin th vg of th img vlu ov th volum of th sph, it is ncssy to divid I by th volum of th sph, hich givs us qution f C f C I V I sph Eqution.7.-6 Eqution.7.-6 is function only of th tio, nd nbls th dtmintion of n xpssion fo Blck s thshold tio solly s function of th tio..7. Blck s thshold Blck s thshold is thn

109 I λ (,) I (,,) I 4 Chpt : Sgmnting tumous fom functionl imging 3 BLACK I, Eqution.7.- Vsph 3 I As I (,,) is function only of th tio, nd kno fom qution.7.-6 tht V sph is lso function only of th tio, thn kno tht Blck s thshold is function only of th tio. In figu.7.-, qutions.7.-6 nd.5.-3 hv bn usd to dtmin th cuv shoing th ltionship btn th thshold SUV nd th vg SUV. Th thshold SUV nd vg SUV in this modl both only dtmind up to th sm bity constnt, hich ill bitily chng th scl of th x nd y xs by th sm fcto, but ill not chng th shp of th cuv. Th globl shp of th cuv is lso indpndnt of th FWHM of th PET scnn, in this modl th FWHM of th scnn simply chngs th point on th cuv to hich pticul volum of sph cosponds. Blck s volum xpimnt usd sph volums nging in volum fom. to 9. cc, nd th domin to hich ths volums pply fo th diffnt FWHM vlus is indictd in Fig.7.- by stight lins dn blo nd plll to th globl cuv. Fig..7.- Thshold SUV vs Mn SUV. In figu.7.- th globl cuv shos th pdictd vition of thshold SUV ginst mn SUV fo th full ng of sph volums fom zo to infinity. Th gdint of th cuv is t zo volum, hn th mn nd thshold SUV both clos to zo, gdlss of th FWHM. This mks sns vn in pixlisd img, hn th volum is smll nough, it occupis only on voxl, in hich cs th thshold SUV nd th mn SUV th sm. Both incs by th sm mount, hnc th gdint is unity. Fo volums clos to infinity, th thshold 87

110 Chpt : Sgmnting tumous fom functionl imging SUV is on hlf of th mn SUV, nd th gdint of th cuv is /3, gin gdlss of th FWHM. In fct this cuv hs th sm shp gdlss of th vlu of th FWHM of th PET scnn. Fo finit ng of volums, th FWHM just govns th sgmnt of th globl cuv tht is ptinnt. Fo sonbl stimts of th FWHM, nd cliniclly lvnt volums, th gdint of th cuv should b ppoching.333 fom bov. As s in tbl.7.-, th is vy littl vition of th locl gdint of th globl cuv ith FWHM. Th th stight lins plll to nd blo th globl cuv dsigntd in th lgnd by FWHMs of.4 cm,.5 cm nd.65 cm sho th domin of th cuv tht pplis to sphs of volums. cc to 9. cc. Expimntlly, Blck potd th lin ltionship btn mn SUV nd thshold SUV givn by qution MnSUV. 588 ThsholdSUV Eqution.7.- Th son tht th lin ltionship dos not pss though th oigin is ppnt fom th shp of th globl cuv in figu.7.- nd th pt of th cuv hich cosponds to th volums of th sphs usd in th xpimnt. Th gdint of th cuv is fo th smllst volum sphs, nd this mks sns fo voxlisd img vn though th voxlistion is not modlld in dtmining qution.7.-. Fo vy smll sphs, sinc th smllst sphs ill b ithin voxl, th thshold SUV nd th vg SUV idnticl, so th gdint is unity. Th sptil solution of th PET scnn 66 hs ldy bn notd in sction.5.6, nd vlus of cm sonbl vlus fo singl FWHM pmt. Fo sphs in th clinicl ng of intst, fo th xpctd ng of FWHM vlus, th cuv is ffctivly lin nd hs gdint ppoching.333 fom bov. Fo this son, th lin ltionship dos not pss though th oigin. Blck s lin ltionship is obtind using SUV vlus tht obtind by multiplying th PET voxl vlus by n undocumntd globl constnt. This globl constnt mks th y xis intcpt of th lin ltionship n bity positiv vlu, but it lvs th gdint of th lin ltionship unchngd, so cn comp th gdint vlu of.37 found by Blck ith th vlus pdictd by qution.7.-. Tbl.7.- givs ths vlus. Tbl.7.- Gdint vlus pdictd by qution.7.- FWHM Gdint Constnt Sum squ o 4. mm mm mm mm mm mm mm mm Blck s fit So cn sho tht if th imging pocss is mly Gussin convolution pocss, thn th mn pixl vlu ov th sph is ltd to th thshold vlu ov th ng of clinicl vlus, nd th gdint is ov th ng of volums obsvd cliniclly. Expimntlly Blck obsvd.37. Blck s fit s to dt tht includd 88

111 Chpt : Sgmnting tumous fom functionl imging sults fom vying FDG concnttion fo th sm volum, s ll s n xpimnt tht vid th volum. Th six dt points ssocitd ith th volum xpimnt hv bn isoltd nd gphd in Figu.7.-. Thshold SUV Figu.7.- Fits to Blck's Dt Mn SUV Blck's Dt Blck's fit m.34 Fig..7.- Fits to Blck s Dt Blck s xpimntl dt comping th mn SUV to th Thshold SUV is shon s gn cosss. Blck s fit to th hol xpimntl dt st, hich includs sults obtind on diffnt dys ith diffnt concnttions, is shon s th d lin. Fitting lin ith gdint of.34 to this dt poducs btt fit..7.3 Clcultion of siduls A sum squ o is listd in tbl.7.- in th ight hnd column. Fo ch of th six sph volums, th diffnc btn th thshold tio pdictd by th modl ith th spcifid FWHM o fo th lst o by Blck s lin fit nd th xpimntlly dtmind thshold vlus dtmind xpimntlly by Blck is clcultd. Thn ch diffnc is squd nd ll six squs summd to gt th sum squ o. Fo th diffnt FWHM vlus th vlus of th constnt is dtmind by optimizing it to minimiz th sum squ o, hil th gdint is clcultd thoticlly fom th FWHM. Th sum squ os fo th ll of th FWHM vlus smll thn fo th fit by Blck..7.4 sons fo gdint discpncy ith Blcks qution. Th numb of possibl sons fo th discpncy of ppoximtly % in th gdint pdictd thoticlly nd th xpimntlly dtmind gdint of.37 dtmind by Blck.. Th mjo cus is xpctd to b xpimntl o.. Additionlly, th concnttion is clos to th 5% dd-tim fo 3D study 66, th pp dos not spcify hth th scpt in (D mod) o out (3D mod). 3. Th sphs hv mm thick shll, in hich th is no bckgound ctivity. This tnds to duc th signl t th piphy of th sph mo thn it ffcts th vg ov th sph. So in th xpimnt lo thshold is msud, sulting in lo gdint. 4. Blck lis on th ADAC Pinncl (ADAC Lbotois, Milpits, CA) sgmnttion lgoithm to clcult th volum. Th ADAC Pinncl volum clcultion uss summtion of voxls, ith boundy voxls off ightd to 5% 67. In th diothpy scnio, pplid to CT contous ith smll voxls thn PET voxls, th ADAC volum lgoithm hs bn shon to clcult volum lys smll thn gomtic mthod

112 Chpt : Sgmnting tumous fom functionl imging 5. Th lls of th volum glss. Th ng of FDG positons ound mm in tissu, but lss in glss. 6. Effct of voxlistion t smll volums. This not such poblm bcus voxlistion puts n vg in ch voxl, so th vg intnsity ill not b ffctd. Th thshold is not gtly ffctd bcus th ltionship n th piphy is nly lin. 7. Th mn SUV nd th vg SUV my simply hv bn nomlizd diffntly. 8. Th modl is incomplt. Fo xmpl, th msumnts of vibl volum hd bckgound concnttion of.44 μci/cc, s opposd to th concnttion ithin th sphs of.87 μci/cc. Th modl (nd Blck) pdict tht this ill not chng th gdint, but th my b scond od ffcts not considd by th modl..7.5 Bckgound ffct on th gdint vlu in Blcks modl In this modl it is xpctd tht bckgound hs no ffct on th gdint, nd Blck lso clims this to hold. This sction sks to xplin hy, in tms of th modl, th bckgound is not xpctd to ffct th gdint. If th bckgound concnttion is.44 μci/cc nd th sph concnttion is.87 μci/cc. Thn th concnttion distibution cn b considd s to imginy sptilly intscting comptmnts, on sph comptmnt holding μci/cc concnttion, nd on univsl bckgound concnttion of.44 μci/cc tht is unifomly psnt vyh, including ithin th sph. Th univsl bckgound of.44 μci/cc, hn imgd, ill poduc unifom signl vyh. No mtt ht th sptil solution, th ill b s much bckgound signl scttd out of voxl s scttd into it. Th ffct of th sph comptmnt ill b th sm s clcultd, xcpt diminishd in ight by th tio.76/.87. Th mn SUV ill thus mp to th vlu of (mn SUV) x.76/ in th psnc of bckgound. Th thshold SUV ill thus lso mp to (thshold SUV) x.76/ in th psnc of bckgound. So th ill b n idnticl lin tnsfomtion to both xs, hich cn chng th y intcpt but not th gdint. Th pimy ssumption is tht th to comptmnts ill dd in th imging pocss, but ny dvition fom this is most likly to b scond od ffct..7.6 Limittion of Blcks mthod Blck s mthod of sgmnting quis only to pmts, gdlss of th lvl of bckgound, hs Edi s thshold mthod quis to pmts fo vy bckgound lvl, hich ould pp to mk Blck s mthod th btt choic. Th limittion of Blck s mthod is tht it dpnds upon th volum bing sphicl in shp, sinc th tio of th thshold to th vg of th volum dpnds on th shp. So Blck s mthod cnnot b gnlizd to non sphicl shps. This cn b dmonsttd by considing sphicl shll 69. Although this is computtionlly convnint, sinc hv modl fo th dil distibution nd th sphicl shll hs dil symmty, it is not ithout clinicl lvnc, sinc lung volum lsions cn hv quit lobul shps tht btt ppoximtd by sphicl shll thn sph, s sn in figu.7.6- blo. Th is lso th knon mtbolic quiscnc of tumou clls in th cnt of lg tumou, hich ffctivly givs is to sphicl shll tumou in function if not in fom. W pocd in th nxt sction to dtmin th thsholds fo th inn nd out sufc of 9

113 Chpt : Sgmnting tumous fom functionl imging 9 sphicl shll tumou, bsd only on th ssumption tht th imging pocss cn b modld s Gussin bluing. Fig Som tumous do hv shps tht ppoximt sphicl shll. Figu.7.6- shos lung tumou imgd ith FDG on stnd lon PET cm (lft) nxt to co-gistd CT scn of th sm slic, tkn fom th utho s on ly ok ith functionl imging. Lung tumous cn pp quit igul nd lobul hn imgd, nd th som lung tumous fo hich sphicl shll is sonbl concptul modl of th ovll shp..7.7 Thsholds fo sphicl shll tumou. Th sphoidl shll tumou (o sphicl tooid o sphicl doughnut) hs dil distibution givn by th dil function of th solid sph (clcultd ith th cnt filld), minus th dil function of n inn sph (clcultd ith th cnt filld but th sphicl shll mpty). W cn find th thshold fom this function. In fct th ill b to thsholds, n inn nd n out. (W ill choos th inn nd out dii to mk th thsholds qul, if possibl). To clcult th vg thshold ov th volum, nt th intgl of th dil function fom th inn dius to th out dius. Givn inn dius nd out dius, th dil function is thn () f f C I f f C C C Eqution.7.7- Th vlu of th dil function t th inn dius is thn f f C I I,,

114 Chpt : Sgmnting tumous fom functionl imging 9 f C C 6 4 C Eqution.7.7- Th vlu of th dil function t th out dius is thn f C I O,, f f C 6 4 C C Eqution And th intgtd vlu ov th volum is thn 4,, d I I Eqution Bking th sphoidl tooid dil function up into dditiv pts, it () () () () () () I I I I I I I I I Eqution h () f C I () f C I () f C I 3 () f C I 4

115 Chpt : Sgmnting tumous fom functionl imging 93 () C I () C I () C I () C I So d I I I I I I I I d I I 4 4,, Eqution ,, d I d I d I I Eqution Considing this tm by tm d f C d I 4 4 Eqution Substitut x ; ; ; dx x d to gt qution dx x f x C d I Eqution Using th idntity givn by qution.7.7-, x x x f x dx x f x x x x Eqution.7.7- givs th solution fo th fist tm, qution C d I

116 C 4 ( ) Chpt : Sgmnting tumous fom functionl imging ( ) ( ) 3 3 ( 3 ) f Eqution.7.7- No considing th scond tm 4C 4 I ( ) d f d Eqution.7.7- Substituting x ( ) ; ; d 8 ( ) 3.5 givs qution x dx ( ) ; 3 C 4 I ( ) d x f ( x) dx Eqution Using th idntity givn by qution ( ) 3 3 ( 3 ) ( ) ( ) x x x dx x f x x x x f 6 Eqution llos solution of th scond tm, qution I 4 C 3 ( 4 3 ) f ( ) C ( ) 3 3 ( ) d.5.5 4( ) 6 ( ) 6 ( ) 3 3 ( 3 ) f ( ) C 4 ( ) 3 3 C.5.5 ( ) Eqution Considing th thid tm 4C 4 I ( ) d f d 3 Eqution x Substituting ; ; d 8 ( ).5 givs qution x dx ; 94

117 Chpt : Sgmnting tumous fom functionl imging 95 dx x f x C d I Eqution Using th idntity givn by qution x x x f x dx x f x x x x Eqution givs th solution fo th thid tm, qution f C d I C C Eqution Considing th fouth tm d f C d I Eqution.7.7- Substituting x ; ; ; dx x d givs qution.7.7- dx x f x C d I Eqution.7.7- Using th idntity of qution x x x f x dx x f x x x Eqution.7.7- givs th solution fo th fifth tm, qution C f C d I C f C Eqution Considing th fifth tm

118 Chpt : Sgmnting tumous fom functionl imging d C d C d I Eqution Substituting u ; u ; du d ; u ; u ; Givs qution u u udu C du C d I Eqution Thn substituting u x ; dx du ; x u ; x u ; givs th fist componnt of tm 5 qution f C du C u 4 4 Eqution Fo th scond componnt of tm5 substituting 4 u v ; dv udu 8 ; v u ; 4 v u givs qution.7.7-8; u C udu C Eqution Which llos us to it th solution fo th fifth tm s qution C f C d I Eqution Considing tm d C d C d I

119 Chpt : Sgmnting tumous fom functionl imging 97 Eqution Substituting u ; u ; du d ; u ; u givs qution.7.7-3; u u du C udu C d I Eqution Thn substituting 4 u v ; dv udu 8 ; 6 v u ; 4 v u ; Givs th fist componnt of tm 6 s qution u C udu C Eqution Substituting into th scond componnt of tm 6 u x ; dx du ; x u ; x u givs qution ; f f C du C u 4 4 Eqution So summing th to componnts givs tm 6 s qution C d I f f C 4 Eqution Considing tm d C d C d I Eqution

120 Substituting u qution ; 4 ; ( u) Chpt : Sgmnting tumous fom functionl imging ; d du ; u ; u givs C du u 4 C I ( ) 7 d 4 u u udu Eqution ; Substituting into th fist componnt of tm 7 x ( ) ; du dx u x ; u x givs qution ; C C du f 4 u 4 Substituting into th scond componnt of tm 7 Eqution u v 4 ; udu 8 dv ; u v ; u v 4 givs qution u 3 C 4 C udu.5 ( ) 8 4 Thn combining th to componnts givs tm 7 s qution I C d 8 3 ( 7 ).5 ( ) C f 4 Considing tm 8 4 Eqution Eqution ( ) 4 4 C I 8 d d d Substituting u qution C 4 ; ( u ) Eqution ; d du ; u ; u givs 98

121 Chpt : Sgmnting tumous fom functionl imging u u du C udu C d I Eqution Substituting into th fist componnt of tm 8 4 u v ; dv udu 8 ; 6 v u ; 4 v u givs qution u C udu C Eqution Substituting into th scond componnt of tm 8 u x ; dx du ; x u ; x u givs qution f f C du C u 4 4 Eqution Which llos us to it tm 8 s qution C d I f f C 4 Eqution Finlly dding up ll tms givs th intgtd vlu ov th sph s qution ,,.5 3 C I f C C f C C f C

122 Chpt : Sgmnting tumous fom functionl imging f C C C C f C C f C C f C C f f C C f C C f f C 4 Eqution To obtin th vg vlu of th volum quis division by th volum, nd this ltionship hs bn gphd in figu.7.7-.

123 Chpt : Sgmnting tumous fom functionl imging Fig Avg vlu ov volum of sphicl shll. Not tht fo smll inn dii, th vg ov th volum is insnsitiv to chngs in th smll inn dius. As th inn dius gts lg, th vg pps to b invint hn th out dius quls th inn dius plus constnt. Th volum chngs considbly ov this ng. So fom sphoidl shll ith.779,., v.8, V3.5 cc to sphoidl shll ith 4.89, 6, v.8, V44 cc; th volum chngs mo thn fold but th vg dos not chng t ll. W cn plot th inn thshold nd th out thshold fo ths sphicl shlls h th vg ov th volum stys constnt, this shos ho much vition in th y xis cn b xpctd fo th singl vlu of mn SUV of.8 in Fig sults of pplying Blck s thshold to sphicl shll Blck s thshold modl quis tht th tio of th thshold SUV to th vg SUV ov th volum b constnt. Using qution , cn stimt th o cusd by pplying Blck s tio mthod to sphicl shll. Givn sphicl shll tht hs n vg of.8, fo scnn ith FWHM of 6.5 mm, th volum cn vy significntly fom minimum of 8.4 cc fo solid sphicl tumou ith zo intnl dius. Ho dos th intio thshold comp to th intnl thshold s volum chngs? Ho dos th volum sgmntd by Blck s mthod comp to th ctul volum of sphicl shll? Wht is th distnc btn th sufcs dtctd by th Blck thshold nd th ctul sufc of th sphicl shll? Figu.7.8- shos th intio nd xtio thsholds s function of th volum of sphicl shll ith volum vg of.8, fo scnn ith FWHM of.65 cm. Fo solid sphicl tumou, this ould cospond to volum of 8.4 cc, dius.6 cm, ppoximtly th sm volum s th smllst volum sph usd xpimntlly by Blck. Th inn thshold ound smll cvity is high, s th inn cvity incss in dius, th inn thshold dcss. Th out thshold incss ith volum.

124 Chpt : Sgmnting tumous fom functionl imging Fig Th inn thshold is vy high fo smll cvity in th middl of sphicl shll, ffctivly dopping fom nly %. Th thsholds clcultd fom qutions.7.7- nd Figu.7.8- shos th vition of th sgmntd volum s tio of th ctul volum. Blck s lgst sph hd volum of 9 cc, nd fo sphicl shll of this volum Blck s mthod ovstimts th volum by 8% o bout 3cc. Fig.7.8- Th volum tio is th volum of th volum sgmntd by Blck s ul dividd by th ctul volum of th sphicl shll. Th jggd ntu of th cuv is computtionl tifct sulting fom gid stimtion of th pmts quid to kp th vg vlu t.8.

125 Chpt : Sgmnting tumous fom functionl imging Figu shos th distnc of th Blck thshold fom th inn nd out sufc of th sphicl shll tumou. At th inn sufc, smll hol of up to 9 mm dimt is nvthlss flsly includd in th volum. Fo lg volum sphicl shlls, th distnc quit quickly dops to lss thn mm. At th out sufc, th o is lmost insignificnt in compison, not ching mo thn.5 mm in th most xtm cs. As th volum incss, this smll systmtic distnc dos tnslt to lg volum. Fig Sinc th Blck thshold lys undstimts th siz of th cntl cvity, th distnc to th inn sufc is th distnc fom th intio sufc of th ctul sph tods th cnt of th sphicl shll nd th inn sufc of th volum sgmntd by th Blck thshold. At th xtio of th sphicl shll, th Blck thshold is ithin th ctul sphicl shll. Th cliniclly most significnt discpncy in pplying th Blck thshold is tht hol of up to 9 mm dimt in th middl of tumou ill b includd in th tumou. On cn gnliz fom tht to th difficulty tht ould b ncountd in pplying th Blck thshold modl to igul shpd tumous..8 EXPEIMENTAL TEST OF THE ADIAL EQUATION Th pcding sctions hv divd modl nd compd its pdictions to vlus vilbl in th littu. In this sction th dil qution is tstd ginst xpimntl vlus tht not vilbl ithin th littu. This ok bgn ith n xtnsion of pvious ok to incopot PET imgs into th TPS (s sction.5), fist to incopot PET-CT imgs into th TPS s shon in figu.8-, thn to dvlop tools fo nlyzing th PET imgs tht not vilbl in th TPS. Th TPS s in th ltt cs usd pimily s visuliztion nd contouing tool. Ths contous thn ccssd nd nlysd by invoking options in th spt mnu bsd C pogm unning on th sm oksttion..8. Intfcing PET-CT imgs into th TPS This s ccomplishd by simpl xtnsion of th pogm mntiond in sction.5. A spt intfc s ittn to dl ith th PET-CT dt fomt, nd diffnt mnu stuctu du to th vilbility of mtching CT slics fom th PET-CT, so tht th no th imgs sts including th plnning CT nd th PET img. Th 3

126 Chpt : Sgmnting tumous fom functionl imging innt co-gisttion of th PET-CT dt s mjo motivtion pomoting mo systmtic tumou sgmnttion fom PET imgs. Fig..8- CT-PET imgs uplodd into th TPS Figu.8. Shos imgs lting fom PET-CT imgs impotd into th TPS. On th lft is th PET img fom th CT-PET, on th ight is th CT img fom th CT-PET. Th lung contou mkd in blu hs bn sgmntd using th TPS bsd on th CT imgs fom th PET-CT. Th lung contou is shon sup-imposd ov th PET img. Th coltion btn th dg of th lung contou nd th mgin of th pt vid mdistinl mss is immditly ppnt, vn ith th infio sptil solution of th PET-CT. Not lso th cuvd couch top of th PET-CT in th CT img on th ight nd th blck dot in th mdistinl mss in th PET img on th lft. Flt top couchs of idnticl constuction to diothpy couch tops subsquntly bcm commcilly vilbl. Th blck dot is mnifsttion of th 3 limit of th TPS disply sn in sctions.5. nd.5.3, nd ultimtly this stiction cusd th pogm to b tmintd fo commcil solution hn on bcm vilbl..8. PET Img nlysis tools fo th TPS. This s futh xtnsion of th mnu bsd C pogm to llo it to d nd intpt TPS contou infomtion s ll s PET img pixl vlus. This llod th inclusion of som xt mnu itms tht implmntd nlysis lgoithms, on of hich llod fo tsting of th dil function. To do this, ch sph hd to b considd sptly, so s fist stp, n xclusiv volum s dn ound ch sph, lg nough to nsu tht ll of th ctul sph volum s includd, but smll nough to nsu tht no oth sph s includd, s shon in figu

127 Chpt : Sgmnting tumous fom functionl imging Fig..8.- FDG sph imgs impotd into th TPS. Figu.8.- shos slic fom th PET img of PET phntom (Jszczk phntom, Dt Spctum Cop., Chpl Hill, NC, USA) ith six FDG lodd sphs of vious volums up to cc. (,,5.5,.5,6,) Th lft nd ight imgs idnticl. Contous hv bn mkd ound th sphs using th TPS to dlint ch individul sph. Ech contou hs numb fom -6 ssignd to it by th TPS. Contou is th ctiv contou nd so is mkd by gn contou, contous -6 mkd in blu..8.3 Algoithm to tst th dil qution. To tst th dil qution quid poducing gph ith PET voxl vlus s th y xis, nd th cosponding distnc of th voxl fom th cnt of th sph s th x xis. Th fist stp in this s to consid ch sph individully. Sinc ch sph hd n xclusiv contou dn ound it, this s ccomplishd by tsting ch voxl to s if it ly ithin th contou. This could b considd s dimnsionl poblm xcutd sptly on ch slic. Th stndd mthod of dtmining if point is insid closd contou s implmntd, stight lin s dn fom th voxl in th xil pln to infinity (in this cs th dg of th img mtix s sufficint) nd n odd numb of intcpts ith th contou indictd voxl tht s ithin th contou, n vn numb on tht s outsid. A mino compliction s tht s both th contou nd th voxl coodints stod s intgs, th nomlly unlikly possibility of tngntil/vtx intsction hd to b considd coctly th thn ignod. Th distnc fom th cnt (in 3 dimnsions) nd th vlu of th voxl thn dily dtmind, onc th cnt of th sph s found. Th x,y dt s thn ittn out in fomt tht could b d by spdsht to poduc th gph. Finding th cnt of th sph s th lst componnt of th lgoithm tht s not initilly stightfod. 5

128 Chpt : Sgmnting tumous fom functionl imging.8.4 Finding th cnt of sph. Th lgoithm chosn to find th cnt of th sph s to fist sch ll of th voxls ithin th xclusiv contou to find th voxl ith th mximum vlu nd its coodints. If th multipl mxim of idnticl vlu thn th fist on found s tkn s th sol mximum. This voxl s thn usd s sd voxl fo constucting contiguous st of voxls hos vlus ll bov thshold tht s ittd fom th mximum pixl vlu to zo until th sgmntd volum s qul to th knon ctul volum of th sph. Th cnt of th sph s thn tkn s th cnt of mss of th sgmntd volum. On bity choic involvd in implmnting this lgoithm is th choic of th thshold fo th sgmntd volum, sinc it cn b sn (Figus.8.4-,.8.4-, nd.8.4-3) tht th position of th cnt of mss of th volum cn vy significntly nd tht this vition cn b monotonic o oscilltoy dpnding on th xis. Pixl (Cdpln) X cntoid sph 3 ough.86e.855e.85e.845e.84e.835e.83e Thshold % Fig Vition of cntoid of cc sph in X xis. In this contxt th X xis mns th L- xis. Whn th thshold is %, th sph volum is ight voxls cntd hlf y btn pixl numb 84 nd 83 in th lft ight diction. In this pticul cs th pixls.3 cm. Initilly s th thshold dops, th ddition of xt voxls hs lg ffct on th cntoid bcus of th smll numb of voxls in th volum. In th mid ng of thsholds th vition bcoms oscilltoy ith mgnitud of bout on qut of pixl o.6 mm. Whn th thshold is vy lo, nd th volum xpnds ll byond th sufc of th ctul sph, th influnc igul xclusiv contou displcs th cntoid. Pixl (Cdpln) Y cntoid Sph 3 ough.5e.45e.4e.35e.3e.5e.e Thshold % Fig.8.4- Vition of cntoid of cc sph in Y xis. In this contxt th Y xis mns th ntio-postio xis. Whn th thshold is %, th sph volum is ight voxls cntd hlf y btn pixl numb nd 3 in th ntio-postio diction. In this pticul cs th pixls.3 cm. Initilly s th thshold dops, th ddition of xt voxls hs lg ffct on th cntoid bcus of th smll numb of voxls in th volum. In th high ng of thsholds th vition bcoms oscilltoy ith mgnitud of bout on hlf to on qut of pixl o. to.6 mm. Whn th thshold is t mdium lvl, th 6

129 Chpt : Sgmnting tumous fom functionl imging cntoid is still oscillting, but ith vy lo mplitud of bout. mm, nd is thus ffctivly stbl in this ng. Whn th thshold is vy lo, nd th volum xpnds ll byond th sufc of th ctul sph, th influnc igul xclusiv contou displcs th cntoid. Pixl (Cdpln) Slic Cntoid Sph 3 ough Thshold % Fig Vition of cntoid of cc sph in Z xis. In this contxt th Z xis mns th supio-infio xis. Whn th thshold is %, th sph volum is ntily on slic 7. In this pticul cs th slic thicknss is.3375 cm. Initilly s th thshold dops, th ddition of xt voxls hs lg ffct on th cntoid bcus of th smll numb of voxls in th volum. In th high ng of thsholds th cntoid vition is lmost monotonic ith dcsing thshold. Whn th thshold is t mdium lvl, th cntoid is still monotonic, but ith lo t of chng. Whn th thshold is vy lo, nd th volum xpnds ll byond th sufc of th ctul sph, th influnc of th igul xclusiv contou displcs th cntoid. Fig Positionl o of cicul fiducil of dius fou pixls shos th positionl o tht sults fom th to dimnsionl displcmnt of th cnt of cicul fiducil ltiv to th pixl gid. Th colou is givn by th to dimnsionl dil distnc btn th cntoid of th pixltd img nd th cntoid of th objct itslf. Th mximum dvition is. of pixl. Th distibution is complx, but onc th dvition is mo thn hlf pixl in ny diction, th pttn ntully pts. Th siz of th fiducil is chosn to b ppoximtly psnttiv of th cntl slic of th cc sph PET img. Finding th cnt of sph is in mny ys nous to finding th cnt of fiducil, subjct hich hs substntil nd sophistictd body of littu 7. Th loction of th cntoid of cicul fiducil objct in pixl is influncd by th position of th tu cnt of th fiducil ltiv to th pixl gid, s shon in Fig Th bity choic s md to us th thshold tht mtchd th ctul volum of th sph to dtmin th cntoid, 7

130 Chpt : Sgmnting tumous fom functionl imging bcus tht thshold is th min point of intst. Th s lso choic to mk btn ighting ll voxls qully hn dtmining th cntoid, o ighting thm by th pixl vlu. Although us of th pixl vlu is hld to incs th ccucy of th cntoid dtmintion by n od of mgnitud, unifom ighting fo th voxls s chosn bcus th sgmnttion is biny, voxl is ith dtmind to b ntily in th volum o ntily out..8.5 Tsting th dil qution on cc sph. No th thoticlly pdictd shp of th dil qution fo th cc sph (Figu.8.5-) cn b compd to th xpimntlly dtmind shp of th dil cuv fo cc sph (Figu.8.5-). Th xpimntl dt is vy noisy, nd th pdictd cuv dos not modl th influnc of nois. Although th xpimntl dt ppoximtly follos th shp of th pdictd cuv, th mximum is not t th cnt, s th thoticl modl pdicts. If th nois is ndom, th mximum is mo likly to b loctd y fom th cnt thn t th cnt of th sph. Clly th nois ill incs th mximum, nd thus duc th thshold. This img is obtind ith no bckgound distibution of FDG, so th volum of th sph cnnot b sgmntd ithout tking th nois into ccount. Figu shos compison of th xpimntl sults, th publishd vlus of Edi nd th thoticl modl. Th xpimntl sults mtch ll fo th smll sphs but th thsholds lo thn pdictd fo th lg sphs. Th is lso som xpimntl nois in th gph, sufficint to disupt th smooth tnd slightly fo lg sphs. This mphsizs th nd fo cln st of xpimntl dt. In th nxt sction th ffct of nois on Edi s sults is ppoximtd. Figu.8.5- dil qution pdiction fo cc sph. cc Intnsity vs distnc s tio of Intnsity / 8

131 Chpt : Sgmnting tumous fom functionl imging Fig Obsvd dil distibution gph fo cc sph. Th dt ppoximtly follos th pdictd shp, but is vy noisy. Ech PET pixl hs in fct bn mppd to fou CT pixls ith nst nighbou intpoltion, so th fou tims th numb of points in this gph, but th noisy xpimntl dt ould compltly obscu ny undlying cuv. It is lso immditly ppnt tht th mximum is not loctd t th cnt of th sph. Sph 3 Yild vs dius 3 5 Yild dius (cm) Thoy vs sults Fig Thoy vsus xpimnt Thshold tio Ntul of on THEOY ACK.7 EDI WITH FWHM.7 cm Figu shos Edi s sults (bon lin) nd th sults dtmind xpimntlly using sphs of volum,, 5.5,.5, 6 nd cc (pink lin). A vlu of.7 cm is usd fo th FWHM to pdict th thoticl gn 9

132 Chpt : Sgmnting tumous fom functionl imging cuv. This lso givs th xpimntl vlus spcific x xis shift, sinc th sphs plottd not ccoding to th volum, but ccoding to th ntul of th dius of th sph dividd by th FWHM..7 cm s chosn s th lgst concivbl FWHM. Th pink lin mtchs closly fo th smll sphs but th thsholds lo thn pdictd fo lg sphs. Th is lso som xpimntl o in th thshold sults, sufficint to disupt th pttn..8.6 Nois nd sgmnttion In th pcding sction it s sn tht img nois must b tkn into ccount hn sgmnting sph volums fom PET imgs. Fo lg volum sphs, cn stimt th ffct of nois on th mximum ithin th sph (nd thfo th duction in th ffctiv thshold) by dict clcultion. If th is cntl ithin th volum of th sph tht hs unifom intnsity bfo nois is tkn into ccount, cn stimt ho much th nois fom mny qul voxls ill incs th mximum. If th N indpndnt obsvtions, ch distibutd in stndd noml distibution bout mn zo ith stndd dvition of on, this mns tht ch indpndnt obsvtion hs pobbility dnsity function givn by qution f z () z Eqution.8.6- W nt to kno th pobbility distibution of th mximum. This is nsd simply by mmbing by dfinition, tht if th mximum is m thn ll of th indpndnt vibls must b lss thn o qul to m. Sinc thy indpndnt th pobbilitis multiply. Th pobbility distibution functions fo th mximum fo six diffnt ods of mgnitud of N indpndnt stndd nomlly distibutd vibls gphd in figu.8.6-.

133 Fig Pobbility distibution fo th mximum. Chpt : Sgmnting tumous fom functionl imging Figu.8.6- shos th pobbility distibution functions fo th mximum fom lft to ight of,,,,,,, nd, indpndnt stndd nomlly distibutd indpndnt vibls. As th numb incss, so dos th mximum, nd it lso bcoms si to pdict th mximum..8.7 Estimting th ffct of nois on Edi s sults. Knoing tht th scn tim is 5 minuts fom th pp by Edi, nd using figu of 4KBq/cc in cm dimt phntom giving 8kcps 7 cn stimt bout 49 counts in ch voxl. W ssum tht th volum of ch voxl is.66 cc (4mm x 4mm pixl ith intslic spcing of 4.5 mm 7 ) nd tk s n stimt of th stndd dvition of sttisticl nois ithin th sph voxl th squ oot of th numb of counts. W futh ppoximt tht th numb of voxls tht cn b th mximum pixl is givn by th volum of th sph dividd by th volum of voxl. This is n ovstimt, sinc th voxls n th sufc hv lo voxl vlu, nd so unlikly to contibut to th mximum. Th ffct of img voxlistion is lso includd in th modl s pviously dscibd in sction.6.3. Th sults shon in tbl.8.7-

134 Chpt : Sgmnting tumous fom functionl imging Tbl.8.7- Mtch to Edi dt including nois Volum dius (cm) N Thshold FWHM FWHM FWHM Eo (ml).65 cm.65 cm TOP.65 cm BOT This is sufficint to gt mtch to th xpimntl dt, nd ncougs us to pusu th modl futh. In this cud ppoximtion, ll th voxls countd s possibl mxim, nd so th nois fom ch dcss th thshold. In th smll sphs, th nois duction of th thshold is vy smll, nd th thshold is dmticlly incsd (ithin bod nvlop) by th pixlistion. It is obvious tht th is som intction btn th chng in signl fom th cnt of th sph nd th nois. Th nois cn lso incs th siz of th nvlop fo smll sphs, but lso if th pixlistion is t vtx, it ill incs th thshold tio, but mo voxls ill b bl to contibut to th mximum. So this suggsts Mont Clo vlution..9 Nois pixltion d-coltion by Mont Clo intgtion Mont Clo simultions spcilly suitd to solving poblms tht qui vging ov lg numb of dimnsions, fo hich stndd gid bsd numicl clcultion mthods bcom computtionlly impcticl. Th disdvntg of Mont Clo mthod is tht th thn th ns ithin knon ccucy, ht is obtind is sttisticl stimt of th ns. 73 To dtmin th Edi thshold of sph of givn volum by th Mont Clo mthod, h th coupld ffcts of nois nd voxl quntiztion t ply, simultion of lg nough numb of tils to obtin libl stimt of th confidnc intvl fo th thshold is xcutd, fo ch til pocding s follos: 3 Fo sph of givn dius, nd thus volum 4 V, imgd ith knon voxl gid sid lngths 3 of V x by V y by V z, consid th dimnsionl y of voxls tht is to voxls lg thn th sph in ch diction. Fist ndomly smpl th loction of th tu cntoid of th sph ltiv to th cntl voxl. This is chivd by smpling unifomly distibutd ndom vibl ov th ngs V x / to V x /, -V y / to V y /, nd V z / to V z /. Vlus outsid this ng simply pt th pttn ith piodic ffct ltiv to noth voxl, nd thus do not nd to b considd.

135 Chpt : Sgmnting tumous fom functionl imging Using th dil qution, vlu is computd fo ch voxl. Fo th volum contining th cntl voxl, numicl intgtion is pfomd ith stps of th of voxl lngth in ch xis. All oth voxls dtmind using th vg of th vlu in ch of th 8 vtics of th voxl s n ppoximtion to th vg vlu of th dil function ov th volum. Thn nois is ddd to th vlus, by smpling stndd nomlly distibutd ndom vibl to ssign positiv o ngtiv cofficint of th nois stndd dvition. Th poduct is ddd to th voxl vlu. Th nois stndd dvition is dtmind in ccodnc ith sction..4. Thn th mximum voxl vlu ov th gid is dtmind. This chivd by but foc, itting though ll voxls to dtmin th mximum. Thn th thshold is ittd fom.5% to 99.5% of th mximum, nd fo ch thshold th numb of voxls gt thn o qul to th thshold is dtmind. An upp thshold is dtmind, hich is th highst thshold tht givs volum lss thn on voxl smll thn th ctul volum of th sph. A lo thshold is dtmind, hich is th lost thshold tht givs volum no lss thn on voxl gt thn th ctul volum of th sph. Multipl tils xcutd, nd th top.5% of th upp thsholds xcludd. Th mximum thshold of th mining 97.5% is tkn s th upp limit of th thsholds fo to sigm, 95% confidnc intvl. Similly th lost.5% of th lo thsholds xcludd nd th minimum of th mind tkn s th lo limit of th thsholds fo to sigm intvl. Th upp nd lo thsholds ttd s indpndnt in this dtmintion. sults of ths clcultions usd to dtmin th vlus in th clcultd upp nd lo thsholds in tbl..-. Th clcultion is quit souc intnsiv, so only tils un fo ch point. Fo smll sphs spcilly, th cn b ng of thsholds tht sgmnt th sm volum, nd th thsholds to sgmnt numb of voxls ith combind volum just lg thn th ctul volum cn b diffnt fom th thsholds tht sgmnt numb of voxls ith combind volum just smll thn th ctul volum 36. Th us of upp nd lo thsholds includs this quntiztion unctinty into th dtmind confidnc intvl. Th upp nd lo thsholds pid, fo ch upp thshold th is cosponding lo thshold. In xcluding outlis to obtin confidnc intvl, th upp nd lo thsholds ttd s indpndnt, simply bcus it is pocdully si to do so. Coupld xclusion ould not chng th nd sult, s th no pis hich simultnously psntd in th upp nd lo jction fctions. 3

136 Chpt : Sgmnting tumous fom functionl imging Th ndom position of th tu cntoid of th sph is only ndomizd ithin singl voxl. By dfinition, this thn bcoms th cntl voxl. As notd in sction.8.4, this ccommodts th full gnlity of th poblm, sinc th distibution pts outsid th cntl voxl. Th xists ng of ys to stimt th nois componnt of PET img in both th clinicl 74,75 nd xpimntl 76,77,78,79,8 contxt. As th nois is smll ptubtion to th thshold, th modl usd in..4, stimting nois fom vition in n xpctd to hv unifom concnttion of FDG nd ngligibl ptil volum ffct, is considd dqut fo us fo this clcultion. List mod mthods 75 not possibl in th xpimnt in sction. bcus th PET scnn did not suppot it.. 3D PET Sph xpimnt Pvious sctions ttd xclusivly ith D PET, but in this sction it is dsid to s th xtnt to hich th simpl modl is vlid fo 3D PET. A PET phntom (Jszczk phntom, Dt Spctum Cop., Chpl Hill, NC, USA) ith six sphs of volum.5 cc,. cc,. cc, 4. cc, 8. cc nd 6. cc filld ith F8. FDG s not usd, but in th xpimntl scnio th us of F8 in solution is quivlnt. Fiv sph to bckgound concnttion tios of infinity (zo bckgound), 7.4, 5.5, 3. nd.8 imgd in spt msumnts. Btn ch msumnt, xt ctivity s ddd to th bckgound comptmnt of th PET phntom, hich s nv compltly full. Th PET phntom s thn shkn to mix th ctivity in, bfo th phntom s plcd on th PET couch nd lft to sttl. Imging s chivd using PET-CT (Gmini Dul PET-CT scnn, Philips Mdicl Systms, Clvlnd, OH, USA) using th 3D-o ction mximum liklihood lgoithm (AMLA) constuction lgoithm. A CT scn s quid to b cquid pio to ch PET img to nbl ttnution coction. Th PET imgs svd to CD-OM in Dicom pt fomt, nd thn d into nlyis soft (MATLAB, Th MthWoks Inc., Ntick, MA, USA) using pupos ittn m fil tht opnd ch slic fil in tun, nd d th img mtix, s ll s th slic spcific scl slop (8,53) nd scl intcpt (8,5). All oth pmts globl nd dtmind by inspction, nd s listd in tbl.-. It is instuctiv to not th coctions tht hv bn pplid to th PET imgs. DECY dcy coctd, ADLnon unifom dil smpling coctd, ATTNttnution coctd, SCATsctt coctd, DTIMdd tim coctd, ANndoms coctd, nd NOMdtcto nomliztion. Th s no contouing cpbility to sgmnt th individul sphs, instd th mtlb nvionmnt s usd to dtmin thshold t hich th six sphs individully solvd in n isosufc plot. This visuliztion s usd to dtmin bounding ctngul pism ound ch sph. (s figu.-) 4

137 Chpt : Sgmnting tumous fom functionl imging Pmt in PET slic fil Vlu Svic Objct Pi Clss (Nucl Mdicin Img Stog) Tnsf Syntx (Littl Endin Explicit Vlu psnttion-non dfult) Implmnttion Vsion Nm BCONN.3. Img Typ Pimy Modlity PT (PET) Mnufctu Philips Mdicl Systms Sttion Nm G3-sv Mnufctu s Modl Nm Allgo Body.C. Slic Thicknss 4 mm Dvic Sil Numb 8 Soft Vsion 9..\PMSPT.44 Potocol Nm ANM Wholbody PET/CT Fild of vi shp CYLINDICAL ING Fild of vi dimnsion 864\8 Smpls p pixl Photomtic Intpttion MONOCHOME os 44 Columns 44 Pixl Spcing 4 mm x 4mm Coctd Img DECY\ADL\ATTN\SCAT\DTIM\AN\NOM Bits Alloctd 6 Bits stod 6 High Bit 5 Pixl psnttion scl Intcpt scl Slop Slic spcific Tbl.- PET scnn img pmts. 5

138 Chpt : Sgmnting tumous fom functionl imging Figu.- PET isosufc visuliztion. Th six sphs h visulizd ith thshold voxl vlu of 5, chosn bcus it s clos to th minimum vlu t hich th sphs individully solvd. Blo this vlu point is chd h th to lgst sphs join. 5 is just und 3% of th mximum voxl vlu of th smllst sph. Th sptil solution of th PET scnn hs bn potd s mm xilly, mm in th tnsvs dil diction nd mm in th tnsvs tngntil diction. 8 Th sptil solution of PET scnns hs bn notd to vy fom unit to unit. 8 A vlu of 6.5 mm s bitily chosn s th mn of 7. nd 5.4 oundd to th nst hlf mm, nd s usd s th FWHM fo th clcultd thsholds... Edi thsholds Th Edi thsholds givn in tbl..-. As th voxls stod s intgs but multiplid by slic spcific scl slop tht is stod s finit solution digitl sting, th thsholds offst hlf pcnt to duc th influnc of ound off on smpling. 6

139 Chpt : Sgmnting tumous fom functionl imging Volum Signl to bckgound tio Expimntl Thshold Mont Clo clcultion upp thshold Mont Clo clcultion lo thshold Eo FWHM 6.5 mm fo 95% CI fo 95% CI.5 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc Tbl..- Edi thsholds. Th clcultd thshold 95% confidnc intvl s dtmind s spcifid in sction.9. Th FWHM usd s 6.5 mm. 7

140 Chpt : Sgmnting tumous fom functionl imging Th xpimntl dt s ithin th clcultd 95% confidnc intvl fo lg sphs ith no bckgound psnt. Th lo thshold fo sph 3, th. cc sph, ith no bckgound psnt, s initilly ithout xplntion, but is blivd to hv sultd fom th uniqu poximity of th sph to n i t intfc (S Figu..-). Sctt in 3D PET is much mo impotnt thn D PET, nd is stongly influncd by poximity to n i t boundy (s figu 3.3 fom Bily 83 ). Fo th smll sphs in th ng of cc nd blo, in 3D PET th po of th lgoithm to discimint btn diffnt volums is vy k, s th dil cuvs ovlp (s Figu..3-). This is lso blivd to b th son tht th modl poposd in sction.9 ill not fit hn ny bckgound is psnt. Fig...- CT slic though th PET phntom. Th PET phntom s nv compltly filld ith t, so tht xt ctivity could b ddd to th bckgound comptmnt. This mnt tht sph 3, th thid smllst sph ith volum of cc, s clos to n i t intfc, unlik th oth fiv sphs... Blck thsholds Th Blck thsholds displyd in figu..-. It is ppnt fom th gph tht bst fit of Blck s thshold ltionship fo 3D PET ould not ccutly pdict th thshold fo ll bckgound lvls. Th modl dos not tk into ccount th gt sctt fction of 3D PET. This dditionl signl outsid th volum of th sph mns tht th concpt of lin supposition cnnot b pplid to th bckgound signl, vn t lo lvls of bckgound. 8

141 Chpt : Sgmnting tumous fom functionl imging Fig...- Th continuous lin is clcultd fom scld vsion of th ltionship displyd in figu.7.-. Th scling s obtind by mking th chng in th Mn SUV fom th smllst nd lgst nd lgst sph in th bsnc of bckgound qul to ht th modl pdicts. Th cuv pdicts th gnl fom of th dt tnd, but good fit is not possibl bcus of th vition ith bckgound concnttion, hs th modl pdicts tht th should b no vition. Th xpimntl points fo diffnt sphs nd diffnt bckgound lvls hv bn plottd ith diffnt colous fo diffnt bckgounds to dmonstt th vition ith bckgound...3 dil ltion Th dil ltion fo th zo bckgound scns givn in figu..3-. Th cntoid s dtmind using th mthod givn in sction

142 Chpt : Sgmnting tumous fom functionl imging Fig...3- Ths th dil distibutions fom th sphs hn th bckgound is zo. Evn ithout bckgound, th smll volum sphs (.5 cc,. cc nd. cc) hv pofils tht intmingl, mking it unlikly tht thy cn b sptd in th psnc of bckgound...4 Nois stimtion Th cntl mm of th 6 cc sph s usd to stimt th nois. Th mn nomlizd vlu s.949, dtmind fom 66 voxls, ith stndd dvition stimtd t.353. In un-nomlisd pixl vlus this is mn of 4.9x 4 nd stndd dvition of.89x 3. Th vinc of th AMLA constuctd img is xpctd to b popotionl to th img itslf. Th nois stndd dvition in singl voxl is thn modld s th squ oot of th voxl to mn tio multiplid by.89x 3 s givn in qution..4-. VOXEL _ VALUE σ NOISE _ VOXEL.89 Eqution Bmbills qutions: Finlly it is instuctiv to vi th sults of Bmbill t l., nd to comp ths sults ith ht ould xpct using Bmbill s sults fo th FWHM of th scnn 84. As mntiond pviously, Bmbill t l dtmind th folloing to qutions using multipl lin gssion mthods 85 on thsholds fo sgmnting sphs of FDG of knon volum (hnc knon intnl dimt, ID) imgd ith Bmbill s PET/CT (Biogph 6 HI-EZ PET/CT scnn, Simns, Hoffmn Estts, IL, USA).

143 Sph ID < mm TH ID Chpt : Sgmnting tumous fom functionl imging % Eqution.- T B % Eqution.- T B Sph ID > mm TH ID Bmbill t l giv FWHM vlus of 4.6 mm fo th tnsxil sptil solution nd 5.34 mm fo th xil sptil solution. To clcult thoticl thsholds to mtch, singl FWHM of 4.84 mm mm is usd. Additionlly fo th pupos of stimting nois lvl, it is ssumd tht th 49 counts p pixl (in fct Bmbill usd ng of concnttions.). Fom ths cn obtin modl pdictions to comp ith Bmbill s sults, shon in tbl.- blo. To mintin consistncy ith Bmbill s ok, th intnl dimt (ID) of th sphs is givn in mm. Th dius, simply on hlf of th ID, is lso quotd in mm. Th λ vlu, th noislss zo bckgound thshold tio givn by qution.5.-, is simply popty of th dius nd th FWHM. Th volum in cubic millimts is lso quotd. Thn th nst intg numb of.65 x.65 x mm voxls tht fits ithin th volum is givn. A mthmticl quntity, (.5) N is th pobbility of ny singl voxl hving vlu lss thn qul to th mximum, ssuming tht vy voxl ithin th sph hs th sm chnc of bing lss thn o qul to th mximum vlu, nd is usd to clcult th incs in th mximum du to nois. Th nxt column givs th nois coction, th incs to th dnominto in qution.5.- du to nois. δ NOISE is givn by.45 tims th numb of stndd dvitions bov th mn quid to chiv th pobbility tht stndd nomlly distibutd vibl ill b lss thn o qul is th vlu of (.5) N. Th column hdd T givs th thshold pcntg if th bckgound signl is ngligibl but nois is psnt B s clcultd. Ths vlus cn b clcultd fom Bmbills fomul but th is no dt msud by Bmbill tht mtchs it. Th nxt th columns giv th thshold pcntgs t thshold to bckgound tios tht msud by Bmbill. Th scond nty in th lst fou columns clcultd by Bmbills fomul. Only on st of vlus givn fo th ID o, bcus only th fomul fo ID> mm is considd. Th ID o is includd only to dmonstt th son fo tking ID mm s bk point btn to modls, t FWHM of 4.84 mm, th modl pdicts tht λ ill tk its minimum vlu of.376 hn th ID is. mm, btn th obsvtions t ID mm nd ID3 mm. In this fct t lst, th modl pdicts n obsvtion. Th closst mtch btn th thshold pcntgs is diffnc of., clos to th xpimntl o, fo th smllst sph ith ID> mm hn th is tumou to bckgound signl tio of 3. Positiv nd ngtiv diffncs obsvd, nd th lgst diffnc is 6.5 fo th lgst sph ith tio of 3. This discpncy is most likly sult of th nding of th qution in Bmbill s pp, sinc it pdicts thshold pcntgs s lo s 7.6%, hil ll thshold pcntgs gphd in th pp gt thn 3%. Comping th modl pdictions to th ctul xpimntl dt, ll th pcntgs tbultd fo th tumou to bckgound tios of 3 nd ithin th 5%-75% intvl. Fo th tumou to bckgound tio of 3, th thshold pcntgs ithin nd bov th 5%-75% intvl, but contind ithin th intvl dfind by th outlis.

144 Chpt : Sgmnting tumous fom functionl imging Tbl.- Bmbill s sults I.D. λ V N (.5) N NOISE δ T B T B 3 T B T B Using th sm multipl lin gssion mthod usd by Bmbill, using th sm disct points, th folloing qution is obtind to mtch ID > mm sphs. TH T B (%) ID Th mximum discpncy btn this qution nd th vlus pdictd by th modl is.6 (diffnc btn pcntgs, 3% compd to 3.6% fo xmpl). Bmbill not tht th thshold pcntg dcss ith incsing ID, th modl pdicts th vs to b tu. If th nois contibution s much lg, this might cus dcs, but it ould hv to b much lg. It is considd tht this indicts limittion of this ok ith spct to PET scnns tht us dconvolution ith th point spd function to nhnc th sptil solution, s Bmbill s scnn dos 86. Th modl clcults th thshold on th ssumption tht th imging pocss intoducs nois sptil bluing, but th img fom th Bmbill s PET/CT scnn hs ldy hd tht sptil bluing ptilly countctd s pt of th imging pocss. Intuitivly, using th modl ith Bmbill s PET/CT scnn iss suspicions of doubl compnsting fo th sm ffct, so th modl should b pplid ith xtm cution to ths scnns. Unfotuntly such n invstigtion is byond th scop of this ok, du minly to lck of ccss to PET/CT lik Bmbill s.. Clinicl lvnc. Th undlying mchnisms bhind th qulittiv bhviou of th thsholds in th Edi thshold hv bn dtmind, nd quntittiv mtch hs bn obtind, lthough it s ncssy to fin th simpl initil modl ith th ddition of coction fo img voxlistion nd noth fo th nois in th img. It hs lso bn possibl to chiv som tying togth of diffnt modls psntd in th littu, though not in ll css.

145 Chpt : Sgmnting tumous fom functionl imging A fist pincipls mthod of sgmnting tumous tht Sphiclly shpd Unifomly PET vid Not ffctd by motion tifct Acquid by D-PET scnn hs bn dtmind, but l lsions t bst only ppoximtly sphicl, nd oftn odd shps. l lsions do not ncssily hv unifomly PET vid. l tumous knon to mov duing th img cquisition nd b subjct to motion tifct. Dptu fom ny o ll of ths th idliztions tnds to dcs th thshold. Th thshold mthod cn thn lys b tkn s n undstimt o minimum volum. Fom clinicl point of vi, thn, th mthod sgmnts lo limit of th clinicl volum tht should thn b xtndd on th bsis of clinicl judgmnt... Envisiond implmnttion Th mthmticl modling of PET thsholds hs in th pst ttctd clinicl citicism ising fom th xpcttion tht th utomtic modl might mginliz clinicl impct. Thfo it is flt pudnt nd justifid to put foth th nvisiond implmnttion of th thshold bsd sgmnttion, vn though th implmnttion is byond th scop of this ok. Nothing in th mthod confins it to sphicl gomty, so th modl cn dl ith lsions of bity shp. Th movmnt of lsions cn b lssnd to som xtnt by gting o motion compnstion. Tht lvs only th poblms of tumou htognity in uptk nd th clssifiction of PET signl s physioic o tumou ltd. Th modl could b xtndd to includ tumou htognity s pmt st by th clinicin. Th clinicin might hv n xpcttion of th ng of tumou htognity xpctd, nd xmin th ng of sgmnttion volums pdictd by th modl fo diffnt htognitis, choosing tht hich in thi clinicl judgmnt bst suitd th clinicl intnt. This ould lso llo documnttion of th sgmnttion in tms of htognity pmt, so tht th mthod of sgmnttion could b tnsfd fom cnt to cnt mo pidly thn locl clinicl knoldg. Clinicl til documnttion could lso b couchd in tms of such htognity coction, so fo xmpl Th lsion should b sgmntd ith thshold tio mthod, using htognity tio of.-.5. Th poblm of clssifying PET signl s physioicl o tumou bsd ould lso qui clinicl input, but could b ssistd by sgmnttion of ntomicl stuctu on th CT scn of th PET CT. H it should b possibl to modl th uptk of FDG by th ogn, tissu o xudt nd modl th xpctd contibution to th distibution. Th clinicl input h ould b th sgmnttion of th stuctus on th CT of th PET CT nd th choosing of th cliniclly lvnt pmts fo th modl. Til mthodoy could lso b couchd in such tms viz Th kidny ill b sgmntd fom th PET CT scn using CT gyscls of upp lvl A Hounsfild Units (HU) nd lo lvl B HU. And th FDG uptk ill b modld using th pmts of th modl by XXX. Although much of th bov is spcultiv nd involvs pocdus nd lgoithms byond th scop of this ok, it hs bn includd s sttmnt of intnt to lly th suspicions of th clinicl stblishmnt. 3

146 .3 Conclusion Chpt : Sgmnting tumous fom functionl imging A qulittiv xplntion fo th bhviou of Edi s thshold hs bn obtind by tting th img s n idlizd continuous function s sn in sction.5.. It s dmonsttd xpimntlly by comping th divd dil qution ith th xpimntlly obsvd dil distibution tht sgmnttion quid nois to b tkn into ccount (sction.8), nd in sction.8.7 it s dmonsttd tht Edi s sults could b pdictd ithin xpimntl o by th inclusion of n ppoximtion fo th ffct of nois. W hv shon ho th thshold fo sgmnting motionlss sphicl tumou ith unifom PET uptk imgd by D PET scnn cn b dtmind fom th sptil solution nd th nois lvl of th PET scnn. Ths both pmts tht xtnsivly chctizd hn PET scnn is commissiond. Th pdictions of th modl bl to d pllls btn th publishd sults of Blck nd Edi, obtind by diffnt invstigtos fo diffnt ng of volums, uniting th to s pdictions of singl modl. Much clinicl ngy hs bn xpndd in conducting tils of PET fo tumou volum mking, hich qui ys of follo up vlution to monito outcoms. Invitbly, givn th lck of consnsus on tumou volum mking mthods ith PET, som of ths tils hv involvd inppopit tumou sgmnttion mthods tht my hv bisd th sults. In mny css, th imging quipmnt my simply no long b vilbl fo subsqunt tsting. In this cicumstnc, th sgmnttion mthod poposd, sinc it lis only on to ll documntd poptis, th sptil solution nd nois chctistics of D PET scnn, my povid th bst stimt, ft th fct, of th diffnc btn th volum sgmntd in th til, nd th mo idly ccptd stimt of th likly ctul tumou, nd thus povid n stimt of ny bis intoducd into th study by th mthodoy. Mthods fo sgmnting tumous fo diothpy ttmnt plnning ith functionl imging cnnot b ny gt us if th infomtion fom functionl imging cn not b tnsfd fom th PET scnn to th diothpy ttmnt plnning systm fo us in tumou volum mking. In th nxt chpt thfo th poblms of infomtion tnsf fo functionl imging ill b xplod. 4

147 Chpt : Sgmnting tumous fom functionl imging (fncs) Lvnkov K, Ptidg M, Cook G, Bd M. Positon mission tomogphy fo tgt volum dfinition in th ttmnt of non-smll cll lung cnc. dioth Oncol 5;77:-4. McMnus MP, Hicks J. Wh do d th lin? Contouing tumos on positon mission tomogphy/computd tomogphy. Int J dit Oncol Biol Phys 8;7:-4. 3 Dvis JB, in B, Hus M, Bug C, Szkly G, Cinik IF. Assssmnt of 8F PET signls fo utomtic tgt volum dfinition in diothpy ttmnt plnning. dioth Oncol 6;8: Nkmoto Y, Skmoto S, Okd T, Snd M, Higshi T, Sg T, Togshi K. Clinicl Vlu of Mnul Fusion of PET nd CT Imgs in Ptints ith Suspctd cunt Coloctl Cnc. Amicn Jounl of ontgnoy 88:57-67 (7) 5 Hong, Hlm J, Bov D, Sthi A, Emmi B. Coltion of PET stndd uptk vlu nd CT indo-lvl thsholds fo tgt dlintion in CT-bsd dition ttmnt plnning. Int J dit Oncol Biol Phys 7;67: Csoli GL, Cttno GM, Cstllon P, t l. ol of computd tomogphy nd 8F fluoodoxyglucos positon mission tomogphy img fusion in confoml diothpy of non-smll cll lung cnc: compison ith stndd tchniqus ith nd ithout lctiv nodl idition. Tumoi 7;93: Zidi H, El Nq I. PET-guidd dlintion of dition thpy ttmnt volums: suvy of img sgmnttion tchniqus. Eu J Nucl Md Mol Imging ;37: Edi YE, Mli O, Lson SM, t l. Sgmnttion of Lung Lsion Volum by Adptiv Positon Emission Tomogphy Img Thsholding. Cnc 997;8: Ymko B, iuk T, obinson D, Muy B, McEn A, o W. Thshold modifiction fo tumou imging in non-smll-cll lung cnc using positon mission tomogphy. Nucl Md Commun 5;6: Wng W, Lson SM, Fzzi M, t l. Pognostic Vlu of [8F]Fluoodoxyglucos Positon Emission Tomogphic Scnning in Ptints ith Thyoid Cnc. J Clin Endocinol Mtb ;85:7-3. Sgouos G, Bllngud AM, Jucic JG, t l. Phmokintics nd Dosimty of n α-pticl Emitt Lblld Antibody: 3Bi-HuM95 (Anti-CD33) in ptints ith Lukmi. J Nucl Md 999;4: Nhmh SA, Edi YE, Ling CC, t l. Effct of spitoy gting on ducing lung motion tifcts in PET imging of lung cnc. Md Phys ;9: Nhmh SA, Edi YE, Pn T, t l. Fou-dimnsionl (4D) PET/CT imging of th thox. Md Phys 4;3: Cldll CB, Mh K, Skinn M, Dnjoux CE. Cn PET povid th 3D xtnt of tumou motion fo individulizd intnl tgt volums? A phntom study of th limittions of CT nd th pomis of PET. Int. J. dit Oncol Bio. Phys 3;55: Lcchi M, Fossti P, Elisi F, Occhi, Lucignni G. Cunt concpts on imging in diothpy. Eu J Nucl Md Mol Imging 8;35: Nimmgdd S, Fod EC, Wong JW, nd Pomp MG Tgtd Molcul Imging in Oncoy: Focus on dition Thpy. Smin in dit Oncol 8;8: Jitt PH, Hounsll A, Cson KJ, t l. Us of combind PET/CT imgs fo diothpy plnning: initil xpincs in lung cnc. B J diol Suppl 5; 8: Mmd M, Abu--lim P, Oliv M, Nosé V, Mmon H, Gbudo VH. FDG-PET/CT tumo sgmnttiondivd indics of mtbolic ctivity to ssss spons to nodjuvnt thpy nd pogssion-f suvivl in sophgl cnc: coltion ith histopthoy sults. Am J Clin Oncol 7;3: Fod EC, Kinhn PE, Hnlon L, Alssio A, jndn J, Schtz DL, Phillips M. Tumo dlintion using PET in hd nd nck cncs: Thshold contouing nd lsion volums Md Phys 6;33: El-Bssiouni M, Cinik IF, Dvis JB, t l. [8FDG] PET-CT-bsdiIntnsity-modultd diothpy ttmnt plnning of hd nd nck cnc. Int J dit Oncol Biol Phys 7;69: Fox JL, ngn, O M W, t l. Dos gisttion of PET nd plnning CT imgs dcs intobsv nd intobsv vition in dlinting tumo volums fo non-smll-cll lung cnc? Int J dit Oncol Biol Phys 5;6:7-5. Hong, Hlm J, Bov D, Sthi A, Bhmn E. Coltion of PET stndd uptk vlu nd CT indo-lvl thsholds fo tgt dlintion in CT-bsd dition ttmnt plnning. Int J dit Oncol Biol Phys 7;67: Su S, Gco C, Glblum D, Yok ED, Jckson A, oznzig KE. 8F-Fluoodoxyglucos positon mission tomogphy-bsd ssssmnt of locl filu pttns in non-smll-cll lung cnc ttd ith dfinitiv diothpy. Int J dit Oncol Biol Phys 8;7: McDmott GM, Wlch A, Stff T, t l. Monitoing pimy bst cnc thoughout chmothpy using FDG-PET. Bst Cnc s Tt 7;:

148 Chpt : Sgmnting tumous fom functionl imging (fncs) 5 Sgouos G, Kolbt KS, Shikh A, t l. Ptint spcific dosimty fo 3I thyoid cnc thpy using 4I PET nd 3-dimnsionl-intnl dosimty (3D-ID) soft. J Nucl Md 4;45: Song H, H B, Pidux A, t l. Lung dosimty fo dioiodin ttmnt plnning in th cs of diffus lung mtstss. J Nucl Md 6;47: V P, Ouvi MJ, Hpdy S, t l. Dos chmothpy influnc th quntifiction of SUV hn contst nhncd CT is usd in PET/CT in lymphom?. Eu J Nucl Md Mol Imging 7;34: Schöd H, Noy A, Gönn M, t l. Intnsity of 8Fluoodoxyglucos uptk in positon mission tomogphy distinguishs btn indolnt nd ggssiv non-hodgkin s lymphom. J Clin Oncol 5;3: But BM, Humm JL, Kooby DA, t l. Using positon mission tomogphy ith [8F]FDG to pdict tumo bhvio in xpimntl coloctl cnc Noplsi ;3: Cinik IF, Hus M, Bug C, Dvis JB, Szkly G. Automtd functionl img-guidd dition ttmnt plnning fo ctl cnc. Int J dit Oncol Biol Phys 5;6: Bssi MC, Tui L, Scchtti G, t l. FDG-PET/CT imging fo stging nd tgt volum dlintion in poptiv confoml diothpy of ctl cnc. Int J dit Oncol Biol Phys 8;7: Lboullux S, Domin C, Bonniud G, t l. Dignostic nd pognostic vlu of 8-Fluoodoxyglucos positon mission tomogphy in dnocoticl ccinom: A pospctiv compison ith computd tomogphy. J Clin Endocinol Mtb 6;9: Boud AO, Zidi H. Img Sgmnttion Tchniqus in Nucl Mdicin Imging. In Zidi H. (Ed.) Quntittiv nlysis in Nucl Mdicin Imging. Singpo: Sping; 6. p Disn J, Sibomn M, Bol A, Doumont T, Lonnux M, Ggoi V. Ti-dimnsionl utomtic sgmnttion of PET volums bsd on msud souc-to-bckgound tios: influnc of constuction imgs. dioth Oncol 3;69: Disn J. Multi modlity imging in plnning ptints ith hd nd nck squmous cll ccinoms: Myths nd lity. [dissttion on th intnt]. Ctholic Univsity of Louvin; 5 [citd Octob 3]. Avilbl fom : Th Liby of th Ctholic Univsity of Louvin Fncois.html 36 Blck QC, Gills IS, Kstin LL, t l.dfining diothpy tgt ith positon mission tomogphy. Int J dit Oncol Biol Phys 4;6: vn Bdijk A, Bumt BG, Bosmns G, t l. Th cunt sttus of FDG-PET in tumou volum dfinition in diothpy ttmnt plnning. Cnc Tt v 6;3: Aistophnous M, Pnny BC, Mtl MK, Plizzi CA. A Gussin mixtu modl fo dfinition of lung tumou volums in positon mission tomogphy. Md Phys 7;34: Jitt PH, Cson KJ, Hounsll A, Visvikis D. Th ol of PET/CT scnning in diothpy plnning. B J diol 6;79:S7-S35. 4 Nstl U, Schf-Schul A, Kmp S, t l. Tgt volum dfinition fo 8F-FDG PET-positiv lymph nods in diothpy of ptints ith non-smll cll lung cnc. Eu J Nucl Md Mol Imging 7;34: Htt M, Lm F, Boussion N, t l. Fuzzy hiddn Mkov chins sgmnttion fo volum dtmintion nd quntittion in PET. Phys Md Biol 7;5: Dv L, obinson DM, McEn A, o W. A locl contst bsd ppoch to thshold sgmnttion fo PET tgt volum dlintion. Md Phys 6;33: Dv L, o W, McEn A, obinson D. Ittiv thshold sgmnttion fo PET tgt volum dlintion. Md Phys 7;34: Dv L, o W, McEn A, obinson D. Compison of th img sgmnttion tchniqus fo tgt volum dlintion in positon mission tomogphy. J Appl Clin Md Phys 7;8: Gonzlz C, Woods E. Digitl img pocssing. nd dn. N Jsy: Pntic Hll;. 46 Jntzn W, Fudnbg L, Eising EG, Hinz M, Bndu W, Bockisch A. Sgmnttion of PET volums by Ittiv Img Thsholding. J Nucl Md 7;48: Montgomy DWG, Ami A, Zidi H. Fully utomtd sgmnttion of oncoicl PET volums using combind multiscl nd sttisticl mthod. Md Phys 7;34: El Nq I, Yng D, Apt A, t l. Concunt multimodlity img sgmnttion by ctiv contous fo diothpy ttmnt plnning. Md Phys 7;34: Bmbill M, Mthoud, Scco C, Loi G, Kngli M, Ingls E. Thshold sgmnttion fo PET tgt volum dlintion in dition ttmnt plnning: Th ol of tgt-to-bckgound tio nd tgt siz. Md Phys 8;35: Bdijk A, Bosmns G, Bosm L, t l. PET-CT-Bsd Auto-contouing in non-smll-cll lung cnc colts ith pthoy nd ducs intobsv vibility in th dlintion of th pimy tumo nd involvd nodl volums. Int J dit Oncol Biol Phys 7;68:

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151 Chpt 3 Infomtion tnsf I might not this bliv Without th snsibl nd tu vouch Of min on ys. Hmlt Act, Scn. Willim Shksp Chpt 3: Infomtion tnsf Contnts 3. Infomtion tnsf Thoticl bckgound Ntok bsics Th tnsmission Contol Potocol Th Intnt Potocol Th Mdi Accss Contol ly Functionl dsciption of ntok potocol lys ncpsulting DICOM Sttgis fo cptuing ntok tffic Intcpting DICOM tffic t comput unning DICOM ppliction Intcpting tffic ov th intvning ntok Filting ntok tffic DICOM Upp Mssg Ly DICOM Mssg Ly DICOM Infomtion Objcts Sttmnt of Hypothss PACS PACS INSTALLATION PACS quy tiv PACS ESPONSIBILITIES PACS fult tcing using pckt sniffing Squntil Dtils of th quy/tiv pocss Summy of th quy/tiv pocss Th ol of th PACS dministto in PACS ollout Dtils of th DICOM stndd quy tiv spcifiction Budgting fo PACS PACS contcts nd DICOM confomnc sttmnts Quy/tiv xtndd ngotition Assocition Ngotition OFFIS DICOM Toolkit:FINDSCU Aftmth

152 Chpt 3: Infomtion tnsf 3.3 CT SCANNE Objctiv, Pocdus, Equipmnt nd sults Th nst DICOM ppliction is not lys th cus of th fult Cus of th communiction fult Clinicl Contxt of th CT communiction fult solution diothpy Simulto Cptu of DICOM dt Dcoding th simulto DICOM byt stm by inspction solution Discussion Conclusion...7 Appndix A OFFIS DCMTK FINDSCU QUEIES GEPACS Infomtion tnsf It s sn in chpt tht cuing poblm ith hybid imging in th diothpy contxt is th flo of infomtion in digitl fom. Whn th us of Hybid imging s in th sch phs, th focus s on ccssing img fils. Th s littl concn bout ho th imgs tnsfd, bcus th initil ptint numbs ltivly lo. In th sch phs, infomtion tnsf ndd only to b possibl, not fficint. As th us of hybid imging in diothpy hs bcom mo idspd nd outin/clinicl, th mphsis hs shiftd fom possibility to pcticlity/lity, nd th mchnism of ccss must b stnddizd nd stmlind to llo th fficint tnsf of this infomtion. In th not so distnt pst, imging infomtion tnsf s chivd by tnspot of hdcopy film imgs. Th only quipmnt ndd to vi th img s light box. In th modn hospitl nvionmnt, imgs no tnsfd in digitl fom, nd qui ccss to pictu chivl nd communiction systm (PACS) oksttion to vi th img. This pplis to mo thn just imgs; schduls nd ppointmnts tht onc mintind by pp systms no hndld digitlly. Although th vity of fomts fo digitl infomtion tnsf in diothpy (fo xmpl TOG fomt, bsd on AAPM pot no ) nd Nucl Mdicin (fo xmpl Intfil, lso bsd on AAPM pot No ), ith th pssg of tim th mjoity of this infomtion tnsf hs com to b mditd by th DICOM tnsf potocol. 3 Modn diothpy nd imging dptmnts cnnot function ithout infomtion tnsf govnd by th DICOM stndd. Th most common nd fficint y fo this tnsf to tk plc is ov locl ntok. In this cicumstnc, hn to DICOM pplictions, fo xmpl CT scnn nd diothpy ttmnt plnning systm, snd imgs btn thm, thy do so by th snd ncoding th infomtion into byt stm hich is thn tnsmittd ov th ntok to th civ, h it is dcodd into n img. Th must b mthod to dtmin fom th ntok tffic btn to DICOM complint pplictions th infomtion tht hs pssd btn thm, bcus tht is th y tht th DICOM pplictions thmslvs communict. Th ctivity of thid pty obtining ny of this dt tnsf by pssivly monitoing th ntok tffic btn th to DICOM pplictions is tmd DICOM pckt sniffing. Th pimy tionl fo undtking this inhntly complx tsk is to dtmin DICOM complinc. Th mjoity of DICOM pplictions communict succssfully, but in multi vndo nvionmnt, DICOM 3

153 Chpt 3: Infomtion tnsf communiction poblms unvoidbl 4. Somtims to pplictions fom diffnt vndos simply ill not communict, fo sons mo complx thn n incoct stting of pmts fom ithin th us o svic intfc. In th invstigto s dict xpinc in this cicumstnc th vndo lys suggsts th non complinc of th oth vndo s ppliction, nd ill not initit coctiv ction until thi ppliction is shon to b t fult. Evn hn th is pim contcto, intfc poblms on of th most significnt tchnicl difficultis ith PACS 5. Log fils my xist on ith ppliction, but thy my not povid th infomtion quid to dtmin hy communiction is not chivd. In this cicumstnc us of DICOM pckt sniffing llos indpndnt nlysis of th poblm. Th dt must b intcptd bfo it cn b dcodd. Intcption is possibl though pssiv intcption t ith ndpoint o by insting pssiv listning dvic into th ntok btn to ndpoints 6. Thn th lys of ntok potocol dt ncpsultion nd to b stippd y to obtin th DICOM infomtion tht psss btn to pplictions. Th DICOM stndd is mo thn fil fomt fo mdicl imgs (o Infomtion Objct Dfinitions, IODs, in DICOM tminoy), it is lso potocol fo dt intchng btn to ndpoints 7. This mns th DICOM mssg ly must fist b intptd to dtmin th syntx bfo th undlying img dt infomtion cn b ccssd. Somtims th son to DICOM pplictions ill not communict ill b found in th mssg ly. Chpt shod multipl xmpls of DICOM Communiction poblms impcting on th us of functionl imging. Th oiginl TPS (CADPLAN, Vin Mdicl Systms, Plo Alto, USA) ould not ccpt PET scns t ll, thy hd to b cst s CT imgs nd sppd into th img fils in th plnning systm to gt thm displyd. Th ly vsions of stotctic TPS (XKnif T TM, dionics, Bulington, MA, USA) ould not llo us of SPECT, it hd to b cst s n MI scn. PET-CT scns could not b d poply by th plnning systm bcus it misd th slic spcific pixl scl vlu. Th sitution hs nd ill impov, lmost ll plnning systms no ccpt functionl imging, nd thid pty systms vilbl 8 to povid co-gisttion nd sgmnttion functionlity, but th us of functionl imging is incsing, nd ith tht coms pssus of tim tht mk ok pocsss much lss tolnt of vn mino fults, hil still xpincing mjo fults fom tim to tim. It is instuctiv to vi som futh fults tht dmonstt th typ of poblms ncountd. Th pocdul th thn soft poblms. Fo xmpl, it hs bn dtmind tht th DICOM tg Body Pt Exmind hs n o t of ov 5% in clinicl pctic, du minly to pocdul o. Th potocol slctd by th CT opto ill st th contnts of th Body Pt Exmind tg utomticlly, but th opto ill pply potocol to impov img qulity s th highst pioity, ithout gd to ny conflict tht my occu btn th body pt fo hich th potocol s dsignd nd th ctul body pt imgd. 9 Th os ith img psnttion tht sult of soft os in th psnttion of th coct img th thn DICOM os. Fo xmpl, uss complind tht PET imgs on th scondy contouing oksttion fuzzy in compison to th imgs displyd on th ssocitd TPS (CMS Focus, Computizd Mdicl Systms, St Louis, MO, USA). To tst this, synthtic PET img of unifom intnsity pixls 3

154 Chpt 3: Infomtion tnsf s snt to th TPS. On th TPS, th img displyd coctly, but on th scondy contouing scn it cm out s n odd gy-scl ttn pttn (S Figu 3.-). This is soft img disply poblm, not DICOM communiction o intpttion poblm, most pobbly sulting fom n incoct implmnttion of dcompssion lgoithm. Ely vsions of th TPS lso fild to implmnt th slic spcific gyscl scl slop fo functionl imgs, sulting in th mximum intnsity on ll slics bing scld to th sm vlu, nd dstoying ny infomtion on th vition of th ltiv intnsity of th imgs in th supio-infio diction, nding th imgs uslss fo diothpy tgt volum mking. Fig. 3.- Focl Es nding of unifom intnsity synthtic PET img coms out s n odd gy-scl ttn pttn, hn it should b unifom gy. This is n xmpl of soft img nding poblm, th thn DICOM img tnsmission poblm. This o s potd by th clinicl uss of th systm, ho notd vitions fom systm to systm of th ppnc of th sm img. Oth os in infomtion tnsmission cn cus gomtic ttmnt os though subtl couption of pocsss du n unfotunt squnc of coincidnc. Fo xmpl, in th cs of tnsint ntok fult, not ll of th imgs tnsmittd by CT-PET might b civd by th dstintion diothpy ttmnt plnning systm. Th CT nd th PET dt, lthough inntly co-gistd, tnsmittd in spt sssions, nd so it is most likly tht if such tnsint ntok fult occus, it ill only stop tnsmission of slics fom ith th CT scn o th PET scn, but not both. If th ntok fult ffcts th tnsmission of only th lst f slics of th PET dt, fo xmpl, th optos my dcid tht tnsmission is not ncssy, spcilly if th mot civs in diothpy hv to tlphon th optos in NM to qust n opto inititd tnsmission, nd if th mot civs ldy kno tht th is no FDG vid diss visibl in th lst f slics. Evn though th PET nd CT dt is inntly co-gistd, th TPS my not utomticlly cogniz this, nd th TPS pocdu my qui both img sts to b slctd nd lodd into th fusion modul to confim this. Stff my ln tht it is only ncssy to nt th fusion modul nd sv th gisttion immditly, ithout ny lttion o img inspction, bfo pocding to us th fusd img dt. Whn to dt sts tht not inntly co-gistd lodd into th fusion modul, th to coodint systms might b so diffnt tht on of th img sts is not vn 3

155 Chpt 3: Infomtion tnsf visibl on th scn disply. This mks mnul fusion fo dispt sts vy tim consuming, s th us hs to sch ound in co-gisttion spc to find th missing img st. Th vndo my choos to mitigt this by modifying th soft to hv th co-gisttion dfult to th cnt of gvity of both img sts, gdlss of thi coodint systm, so both img sts ould lys initilly visibl. Unfotuntly this mns tht fo inntly co-gistd CT-PET img sts, if th to slics missing fom on nd of th CT dt st, gomtic o of on slic sption ill b intoducd. Although th bov xmpl sounds lik f ftchd scnio, it occud in pctic. Fotuntly it s dtctd s n miss tht s intcptd just bfo ttmnt, nd vi of th stod co-gisttion mtics fo ll pvious CT-PET ptints shod tht no pio o hd occud. Th idl y to ovcom this o is fo CT-PET vndos to stmp both th CT nd PET dt ith th sm fm of fnc UID, nd fo th TPS vndos to implmnt thi soft so tht h th fm of fnc of to civd img dt sts is idnticl, to implmnt n ppopit co-gisttion mtix ithout us intvntion. It tks tim fo vndos to dvlop obust pocdus to hndl DICOM dt, nd th pocdus usd in diothpy bcoming mo complx, just s th DICOM potocol is constntly volving. It is difficult to pdict in dvnc th spcifics of ho DICOM communiction poblms might impd th us of functionl imging in pticul dptmnt, but diothpy cnt is incsingly likly to obtin its imging infomtion indictly fom mot quy of PACS systm, th thn by opto inititd dict tnsf fom th CT-PET, o CT-SPECT unit. An inbility to ccss th PACS systm by mot quy ill ffctivly stop ll us of functionl imging. Th pimy illusttiv xmpl fd to ill thfo b PACS, subsqunt to n upgd, hich ould no long llo diothpy ttmnt plnning systm to ccss th PACS dtbs. Suddnly th diothpy dptmnt hd no ccss to PACS, nd numb of ptints hd thi ttmnt plnnd ithout fnc to MI scns tht ould othis hv bn vilbl. Such fult ould lso ffctivly stop th us of functionl imging in dptmnt tht s hvy us of functionl imging, hich is th diction tht diothpy pctic is hding. This xmpl is l incidnt, nd txt in itlic giving dtils of th ctul incidnt in chonoicl od is intspsd ithin th txt to giv contxt to th gnic dsciptions of pocss ndd in th stndd font. This disupts th icl psnttion od of th bstct concpts, but th od of vnts is typicl of fult situtions nd povids much ndd ntiv thm to n othis dull topic. A scondy illusttiv xmpl is cs of n imging modlity unbl to communict ith diothpy ttmnt plnning systm. Dict tnsf fom th imging modlity to th dition ttmnt plnning systm is bcoming, nd tnds only to b usd hn th is no PACS systm vilbl (o potntil okound fo PACS systm tht is tmpoily offlin), o fo lly lg siz imgs tht my b dmd to lg to b stod on PACS, o of intst to diothpy only nd not quid to b gnlly ccssibl (usully this mns th PACS stog cpcity hs bn und spcifid). Th pticul xmpl is th cs of n CT instlltion, th fist in Austli of tht pticul modl, h it s found ft instlltion tht th min TPS tht pviously civd imgs fom th old CT scnn could not do so ith th n on. Th vndos ch suggstd th non complinc of th oth s quipmnt. Th s gt dl of pssu to fix th poblm quickly bcus th diothpy ttmnt plnning oklod hd mountd up hil th n CT s bing instlld. 33

156 Chpt 3: Infomtion tnsf Th thid xmpl is not dictly ltd to functionl imging, but is includd s n xmpl of fult tcing sitution h th DICOM pckt sniffing ppoch s th only possibl ppoch, bcus th DICOM mditd pocss s utomtic, so tht it s not possibl to bk th poblm don into stps nd s h th fult os ithin ith ppliction. Th diothpy hybid imging okflo is not ll nough stblishd vn to b bl to pdict no ht th most impotnt utomtd pocss ithin it ill b, but htv thy, thy ll potntilly vulnbl to poblms ising fom DICOM communiction poblms. Th pticul xmpl tht ill b follod is digitl diothpy simulto ith DICOM Pint function. Whn it s linkd to DICOM film pint th sulting output s not scld coctly. This s initilly impotnt cliniclly bcus of dsi to poduc th function of th pvious simulto, hich poducd films of pticul scls. This sction of th thsis on infomtion tnsf focuss igoously on th minuti of infomtion tnsf, but ths dtils hv nomous consquncs ith dily idntifibl conomic vlu. Though th us of th tchniqu of diothpy DICOM pckt sniffing it hs ctully hppnd tht subtl poblms ith intfcing multi million doll quipmnt, hich might othis hv bn unusbl fo th mdicl pupos fo hich it s puchsd, fo months o vn ys du to DICOM communiction poblms, hv bn solvd in singl ftnoon. 3. Thoticl bckgound This sction bgins ith dsciption of th thoticl bckgound of diothpy DICOM Pckt sniffing nd concluds ith sttmnt of th hypothss. 3.. Ntok bsics Th siz of fil psnting singl CT img is typiclly bigg thn hlf mgbyt. Whn this dt is tnsmittd s byt stm ov comput ntok, it is bokn up into mny pckts ch of bout on nd hlf kilobyts ith th lys of potocol ncpsulting th DICOM CT dt. 3.. Th tnsmission Contol Potocol All DICOM dt is ncpsultd ithin Tnsmission Contol Potocol (TCP ) pckts (Tbl 3..-). Th pts of th TCP hd tht lvnt to ccssing th DICOM tnsmission dt th Souc Pot, Dstintion Pot nd 4 bit Dt Offst. Th squnc numb nd th cknoldgmnt numb quid if th TCP pckts iv out of od, but cn usully b nglctd fo tst puposs. Th initito of DICOM sssion ill hv bn configud to ssign dstintion pot to th tnsmission. Th civing DICOM ppliction nds to b configud to xpct DICOM tnsmission on th sm pot fo th communiction to initit succssfully. Th souc pot numb is only n bity numb usd to diffntit multipl sssions. In th vs TCP tffic th pot numbs ill b intchngd. Th fixd lngth pt of th TCP hd is follod by vibl lngth options fild, thn th ncpsultd TCP dt if ny. Th 4-bit Dt Offst is thus quid to find th stt of th ncpsultd DICOM dt. Th numb of byts fom th bginning of th TCP hd to th stt of th ncpsultd DICOM dt is givn by th vlu in th TCP Dt Offst fild multiplid by 4 s consqunc of th ncpsultion uls of th TCP. Th nd of th ncpsultd DICOM dt cn only b found by fing to th totl lngth spcifid in th intnt potocol (IP) hd ncpsulting th TCP pckt. 34

157 Chpt 3: Infomtion tnsf Tbl 3..- Th stuctu of th TCP hd, ith lmnts quid fo dcoding th ncpsultd DICOM pckts highlightd. Bit offst Bits -3 Bits 4-7 Bits 8-5 Bits 6-3 Souc Pot (Bits -5) Dstintion pot (Bits 6-3) 3 Squnc numb (Bits 3-63) 64 Acknoldgmnt numb (Bits 64-95) 96 Dt Offst svd Flgs Windo siz 8 Chcksum (Bits 8-43) Ugnt point 6 Options 6/9 Dt 3..3 Th Intnt Potocol Th tm intnt divs fom th titl of th oiginl pp, "A Potocol fo Pckt Ntok Intconnction." 3 Th pp dscibd n intntoking potocol fo shing soucs using pckt-sitching mong nods, hich subsquntly bcm on of th dtmining lmnts tht dfin th intnt. Th TCP pckts in tun ncpsultd ithin IP pckts (Tbl 3..3-). Th pts of th IP pckt hd tht lvnt to DICOM dt tnsmission th hd lngth, th totl lngth, th potocol nd th IP souc nd dstintion ddss. Th fixd lngth pt of th IP pckt hd is follod by vibl lngth option fild, hich cn b ffctivly ignod, but its lngth nds to b knon to dtmin h th nxt ly of ncpsultd TCP dt stts. Th vlu in th 4 bit Hd Lngth fild indicts th totl lngth of th IP hd in multipls of 3 bit ods. Th Totl Lngth fild spcifis th lngth of th IP pckt, including both th vibl lngth IP hd nd th ncpsultd dt pckt. Fo ll DICOM pckts th 8-bit potocol fild is lys st to hxdciml vlu 6 to signify tht th potocol of th dt ncpsultd ithin th IP pckt is TCP. Th souc nd IP dstintion ddss st by th configution of th DICOM pplictions. Tbl Th stuctu of th IP hd, ith lmnts quid fo dcoding DICOM pckts highlightd. Bit Offst Bits -3 Bits 4-7 Bits 8-5 Bits 6-8 Bits 9-3 Vsion Hd Lngth Typ of svic Totl Lngth (Bits 6-3) 3 Idntifiction (Bits 3-47) Flgs Fgmnt offst 64 Tim to liv (Bits 64-7) Potocol st to Hd Chcksum (Bits 8-95) 6 TCP 96 Souc IP ddss (Bits 96-7) 8 Dstintion IP ddss (Bits 8-59) 6 Options (Zo o mo multipls of fou byts) 6 o 9 Encpsultd TCP pckt 35

158 3..4 Th Mdi Accss Contol ly Chpt 3: Infomtion tnsf Th IP pckts futh ncpsultd by th mdi ccss contol (MAC) ly (Tbl 3..4-). Th stuctu of th MAC hd consists of six byt dstintion ddss, six byt souc ddss nd to byt typ fild. Th typ fild is lys st to hxdciml 8 in ll pckts lvnt to DICOM. This indicts tht th ncpsultd dt is n IP pckt. Th lngth of th ncpsultd dt is not dfind by th MAC hd, but ithin th dt itslf. It is lys btn 46 nd 5 byts. Th ncpsultd dt is follod by fou byt cyclic dundncy chck fild. Tbl Th stuctu of th MAC Hd MAC dstintion MAC souc Typ Encpsultd (IP Pckt) Cyclic dundncy chck BYTES Functionl dsciption of ntok potocol lys ncpsulting DICOM Th TCP potocol is connction ointd, libl, byt stm svic ncpsultd ithin th IP potocol, hich is n unlibl, connctionlss dtgm dlivy svic. Th MAC ly uniquly idntifis th snding nd civing ntok cd fo th pckt by thi MAC ddsss. A dtild discussion of TCP/IP ntoking is outsid th scop of this thsis, nd is covd dqutly by suitbl txtbook 4 o intnt souc Sttgis fo cptuing ntok tffic A DICOM tnsmission involvs convstion btn to DICOM pplictions tht lys quis bidictionl infomtion flo. Th infomtion tnsmittd by DICOM fom CT to TPS my b just s impotnt to finding solution to poblm s th communiction in th opposit diction. Whn DICOM ppliction A communicts ith DICOM ppliction B th th plcs tht th dt cn b intcptd, th comput unning ppliction A, th comput unning ppliction B nd th ntok in btn. Intcpting th dt t comput unning n ppliction is th sm gdlss of hich nd it is, so th in fct only to scnios to consid, intcpting t comput unning DICOM ppliction o intcpting ov th ntok Intcpting DICOM tffic t comput unning DICOM ppliction If ccss is possibl to ith ndpoint host comput, it my b possibl to intcpt th ntok tffic th. On indos PC, us of ith th thl ntok potocol nlyz 6, o its succsso ishk 6,7, hs th dvntg of built in DICOM stndd potocol nlyz. Altntivly if th ndpoint is on linux o unix systm, th tcpdump 8 utility is vilbl. Povidd tht tcpdump is xcutd by us pofil ith sufficint scuity pivilgs, this ill llo ll th ntok dt to b svd to fil fo lt nlysis. If th svd fil cnnot b xtctd fom th host systm, thn it is possibl to ct cod on th host to vi it on th systm. Th tcpdump biny svd fil stuctu is not stnddisd but cn b gnlizd 9 s 4 byt fil hd ith 6 byt pckt hds (ssntilly tim stmp nd pckt lngth pcding th cod of ch pckt) compising n dditionl ly of 36

159 Chpt 3: Infomtion tnsf ncpsultion of th DICOM dt. It is lso possibl, but xtmly tdious, to dcod th cptud byt stm by inspction, using hx dito Intcpting tffic ov th intvning ntok Th IP potocol s dsignd fo dundnt tnsmission, nd th pth tht pckts follo though th ntok cn chng dynmiclly in spons to ntok congstion. Th TCP potocol ill tolt th ivl of pckts out of od nd by diffnt outs. Fotuntly comput unning DICOM ppliction is usully only connctd to th ntok by singl ntok cbl, though hich ll of th quid infomtion hs to flo. A ntok hub is n Opn Systms Intconnction (OSI) modl (ISO/IEC 7498-:994 ) ly dvic, hich mns it simply copis th dt pckts it civs to ll dvics connctd to its pots, ithout disciminting on th bsis of ny of th infomtion in th pckts. Hubs not oftn usd in ntoks tody bcus thy too slo, multipl pots cnnot tnsmit t th sm tim, so th spd of th hub is ducd by th numb of diffnt pots. Most infomtion tchnoy tchnicins ill hv t lst on unusd hub gthing dust somh. If hub cn b intposd btn th ntok nd comput unning DICOM ppliction thn ll quid dt cn b cptud (Figu 3..7-). Nomlly th comput unning DICOM ppliction is connctd to th ntok by singl ptch cbl. With th ddition of to xt ptch cbls, hub nd lptop unning ishk, th lptop cn vi ll DICOM dt to nd fom th comput unning th DICOM ppliction. Disconncting th host fom th ntok quis cution, most systms ill tolt bing disconnctd fom th ntok tmpoily s th Ethnt cbl connctions chngd but it my b ncssy to boot th host o hosts in spcific od to stblish connction if thy do not. Onc th hub is in plc, pssiv listning comput cn b connctd to on of th pots of th hub to cptu th ntok tffic. A fst lptop comput unning thl o ishk is idl fo this pupos. Th mthod bov cn b dscibd s hd mthod fo intcpting tffic; n ltnt mthod put fod by Cook involvs using lptop ith to ntok cds connctd to intpos th lptop btn th ntok nd th DICOM ppliction comput. A soft bidg is thn implmntd on th lptop to llo tnsmission nd suvillnc of ntok tffic. This outcom is idnticl, but Cook s mthod voids th us of hub, hich is n dvntg if th IT dptmnt contolling th ntok fuss to llo hub to b connctd. A pssiv obsv hs no contol of th tnsmission t, nd cn somtims los pckts duing tst of tnsf. Th loss of ths pckts ill b potd by th cptuing soft, nd th simpl solution to this is to pt th tst. DICOM pckt sniffing dos not qui th sm libility s dict DICOM tnsmission. Only on cln coding of th ntok tnsmission is quid to ccss th infomtion tnsf btn th to DICOM pplictions. 37

160 Chpt 3: Infomtion tnsf Fig Intposing hub btn DICOM p nd th ntok. If n old hub is usd, th connction btn th ntok point nd th hub my qui cossov cbl, th thn th stndd stight-though ptch cbl 3..9 Filting ntok tffic Wishk llos th disply of cptud ntok dt to b limitd to DICOM stndd potocol pckts. On y to do this is to nt th th ltts dcm in th filt box (Figu 3..8-) ithin th ishk ppliction nvionmnt. This instucts ishk to dcod th upp lvls of th DICOM potocol nd disply th infomtion in gphicl fom. If implmnting ishk is not possibl, thn cud but ffctiv bit/byt lvl lgoithm to filt out th DICOM stndd potocol byt stm in on diction fo nlysis is to mov 4 byt indo though th codd ntok tffic byt by byt, chcking fo mtch to suitbl MAC hd. This voids coding fo ll possibl ntok potocols to b bl to pick out th DICOM byt stm. Onc th TCP hd ly hs bn stippd y nd ll th pckt contnts joind togth, ht mins is to y byt stm communiction tht is compltly spcifid by th DICOM stndd. Th is stict squnc to this communiction; th ction of on ndpoint cnnot bgin until th pompting ction fom th oth ndpoint hs finishd. Th uls fo this squnc dfind in pt 8 of th DICOM stndd, Ntok Communiction Suppot fo Mssg Exchng, hich dfins th DICOM Upp Mssg Ly. Th bsics of ths uls dscibd in th nxt sction. Fig Wishk llos utomtic disply limitd to DICOM stndd potocol pckts, just by nting dcm in th Filt box. 38

161 3.. DICOM Upp Mssg Ly Chpt 3: Infomtion tnsf All DICOM communictions bgin ith th initito snding n ssocition qust. Th ssocition qust includs th Appliction Entity Titls of th snd nd th civ. Th civ thn snds bck n ssocition qust spons. Th foming of n ssocition cn b thought of s ngotition bout ht svics ill b povidd nd ho thy ill b nmd nd ncodd. Onc n ssocition is fomd, th DICOM Upp Mssg ly P-DATA- TF mssgs cn b usd to snd ncpsultd DICOM Mssgs, hich cy ll DICOM communiction oth thn tht involvd in foming nd nding DICOM ssocitions, jointly fd to s th DICOM Mssg Ly. 3.. DICOM Mssg Ly Th DICOM mssg ly is ncpsultd ithin th psnttion-dt-vlu itms of th DICOM Upp Mssg Ly. Ths ncpsultion uls spcifid in DICOM Pt 8 Appndix E. All DICOM mssgs ncpsultd ithin Psnttion-Dt-Vlu Itm ddss th psnttion contxt dfind ithin tht itm. DICOM mssgs ith dt o commnd mssgs nd fgmntd. Ech fgmnt is pcdd by on byt hd tht dsignts if it is th lst fgmnt of th mssg, nd hth it is commnd o dt fgmnt. 3.. DICOM Infomtion Objcts All dt tnsmittd ithin DICOM mssgs is compisd of infomtion objcts, hos stuctu nd mning is dfind ithin pt 3 of th DICOM stndd, Infomtion Objct Dfinitions. An IOD usd to psnt singl clss of l-wold Objcts is clld Nomlizd Infomtion Objct. An IOD hich includs infomtion bout ltd l-wold Objcts is clld Composit Infomtion Objct. DICOM Pint is nomlisd infomtion objct, s is DICOM sto. DICOM quy tiv is composit infomtion objct Sttmnt of Hypothss Hving dscibd th thoticl bsis, th hypothss dvncd in spct of diothpy DICOM Pckt Sniffing. Th fist hypothsis is tht th clss of DICOM poblms in multi-vndo nvionmnt fo hich DICOM pckt sniffing povids mthod fo idntifying hich vndo (o both o nith) is t fult. This hypothsis ill b dmonsttd pcticlly by xmpl ith fnc to th PACS scnio. Th scond hypothsis is tht fo subst of th poblms fom th fist hypothsis, it ill b possibl to implmnt solution ith locl soucs. Th scond hypothsis ill b dmonsttd pcticlly by xmpl ith fnc to th scond xmpl, th plnning comput/ct intction poblm. Th thid hypothsis is tht fo subst of th poblms fom fist hypothsis, DICOM pckt sniffing povids th only pcticl mthod fo clssifying th poblm. This thid hypothsis ill b dmonsttd by th thid xmpl, poblm involving DICOM pint nd diothpy Simulto. Absnt fom this list is th hypothsis tht DICOM pckt sniffing llos ll DICOM poblms to b clssifid, ith on its on o in conct ith oth tchniqus. Unfotuntly th DICOM potocol povids no pscibd 39

162 Chpt 3: Infomtion tnsf mchnism fo dtmining DICOM complinc, nding such hypothsis stictly un-povbl. Pcticl ffots to ppoch such mchnism, such s th Dicom Vifiction Toolkit 56 (DVTk), lg collbotiv ndvos byond th scop of this ok. 3. PACS This sction dtils n xtndd incidnt t th Alfd Hospitl tht occud hn th PACS systm s upgdd, but it ill b sn tht th undlying poblm s potntilly globl in scop. Although th n PACS vsion s nmd s n upgd to th pio vsion, commcil cquisitions mnt tht th to vsions compltly diffnt poducts nd th pocss s oll out of n PACS systm in ll but nm. Th incidnt s not dill, no s it ny y contivd. Excpts fom th cod of th incidnt s it hppnd put in itlic in this sction, nd givn in chonoicl od, immditly folloing th ppopit tchnicl considtions. 3.. PACS INSTALLATION ollout of PACS systm is mjo pojct fo hospitl. Th fist stp in cquiing PACS fo ny hlthc ntpis involvs pfoming okflo nlysis, nd documnting us quimnts 3. Budgting fo such pojct should includ som povision to dl ith intfcing poblms 4. It is commndd tht th pojct b divn by multi-discipliny sting committ ith clinicl, dministtiv nd tchnicl psnttion, dtild nd comphnsiv implmnttion pln, nd stgd instlltion 5. PACS is considd mission citicl systm fo ound-th-clock dily clinicl option 6. Whn n old PACS is ldy in us, it my nd to b un in plll ith th n systm fo months bfo libl implmnttion of th n PACS is chivd 7. On dy in 7 dition thpist fom WBC ttmptd to lod n MI scn into th Eclips ttmnt plnning systm fom th hospitl PACS using th Eclips PACS quy tiv soft, folloing documntd pocdu tht hd bn usd succssfully mny tims bfo Th PACS dtbs potd tht th s no ptint ith tht nm in th dtbs. Th thpist thn ccssd th PACS dtbs dictly using PACS b bos ppliction nd s bl to disply, but not impot, th quid ptint imgs. Whn th discpncy s potd to th PACS dministto, th thpist s infomd tht th hospitl hd upgdd th PACS systm th months pio, nd th dtbs ssocitd ith th old PACS vsion s no long bing updtd. Th PACS dministto infomd th thpist tht thy ould nd to quy th n dtbs to obtin th infomtion. 3.. PACS quy tiv Pio to th implmnttion of PACS quy tiv svic, img dt s tnsfd dictly fom imging modlitis to th diothpy ttmnt plnning systm by DICOM C-Sto inititd by th imging modlity opto fom th opting consol. This tnsf s oftn pomptd by phon cll fom diothpy ttmnt plnn, somtims could not b inititd hil th imging modlity s in n imging sssion, nd fom tim to tim might nd to b ptd. Th imgs might lso b qustd ft thy hd bn chivd, ncssitting th tivl of th imgs fom bckup mdi optimizd fo stog cpcity t th xpns of spd of ccss. Th 4

163 Chpt 3: Infomtion tnsf img tnsf could b md to ok in clinicl pctic, but it s infficint nd fustting fo ll concnd. Within th id hospitl, digitl imging modlitis oftn pintd out nd tnspotd fo vi s films. This s okbl but infio systm, films somtims lost nd lys difficult to tnspot in n fficint nd timly mnn. Only fction of th digitl img infomtion could b codd on film, nd th nding ndd to b dcidd pio to pinting, hich s oftn pio to vi. Whn PACS systms intoducd in imging dptmnts, th lmost univsl ppoch s to chiv ll imgs to th PACS systm immditly ft thi cquisition, gnlly s n utomtd pocss tht quid no intvntion fom th imging modlity opto. Th dvnt of mot quy llod th TPS opto to us quy tiv clint to tiv img dt fom th PACS immditly thy bcm tht th infomtion s quid. Th supio fficincy of th mot quy systm llod humn soucs to b -lloctd to high pioity plnning tsks, t hich point dict img tnsf bcm pcticl impossibility, nd mot quy bcm n ssntil ntok svic tht th diothpy dptmnt could not function poply ithout. In th id hospitl, digitl imgs vid on dmnd though PACS ith djustbl infomtion nding. Th Alfd Hospitl dioy Dptmnt, togth ith GE Hlthc Tchnois, civd high commndtion t th Victoin Engining Excllnc Ads fo th fist PACS systm in 5 8. With th ssistnc of th hospitl PACS dministto, th Eclips ttmnt plnning systm s configud to ccss th n PACS dtbs. Although this md it possibl to coctly bos th vilbl ptints, studis nd sis, hnv th pimy function of tiving sis to th diothpy ttmnt plnning systm s ttmptd, th mot quy clint tund mssg tht non of th slctd objcts could b impotd PACS ESPONSIBILITIES Th qustion s to hth nd to ht xtnt mdicl physicists should ssum PACS sponsibilitis s th subjct of point/countpoint discussion in Mdicl Physics in 9. Agumnts fo PACS sponsibilitis s th Mdicl Physicist s bidging gps btn infomtion tchnoy nd PACS. Agumnts ginst involvmnt tht it is fo Mdicl Physicist distction fom th min tsk. A ntok nlyst fom th hospitl IT dptmnt monitod th ntok tffic btn th diothpy ttmnt plnning systm nd th PACS sv using thl 6. Thy bl to obsv tht th diothpy ttmnt plnning systm s bl to opn TCP sssion ith PACS sv nd tht TCP pckts libly tnsmittd ithin tht sssion. Th hospitl IT dptmnt indictd tht thi ol s limitd to suppot of ntok communiction don to th lvl of TCP communiction, nd tht in consqunc thy hd no futh sponsibility o ol in cocting th poblm PACS fult tcing using pckt sniffing Th ntok tffic btn TPS (Vin Eclips DICOM Quy tiv Svic V7.3) nd PACS (GE Cnticity PACS 3., GE Hlthc Infomtion Tchnois, Mount Pospct, IL, USA) s cptud by 4

164 Chpt 3: Infomtion tnsf intposing ntok Hub btn th TPS nd th ntok. A lptop unning ishk (Vsion.99.8) s usd to cptu th DICOM byt stm. Annottd scn dumps compild coding th us ctions nd th subsqunt DICOM communiction to nd fom th PACS Squntil Dtils of th quy/tiv pocss In this sction th quy tiv pocss s it ppd to th diothpy ttmnt plnning systm us is psntd in 5 illusttd stgs (Figus to ). diothpy DICOM pckt sniffing nbld th DICOM infomtion xchng to b dtmind t ch stg, nd bif dsciption of this is givn t ch stg. Stg On: Th us lft clicks th mous to slct mnu option Fil, thn Impot, thn holds th lft mous button don ithout lsing it on th Wizd option. Th is no DICOM ctivity, but th TPS displys th highlightd choic s shon in Figu Fig Th is no DICOM ctivity, but th TPS displys th highlightd choic s th Impot Wizd. Ptint nms hv bn obscud. 4

165 Chpt 3: Infomtion tnsf Stg To: Th us lss th lft mous button to complt th slction of th Impot Wizd option. Th is no DICOM ctivity, but th TPS opns th Impot Wizd Filt indo s shon in Figu blo. Fig Th is no DICOM ctivity, but th TPS opns th Impot Wizd:Filt Slction Windo. Stg Th: Th us clicks nd lss th lft mous button to slct th PACS Quy tiv Svic. Th is no DICOM ctivity, but th TPS updts th Impot Wizd Filt Slction Windo to sho th slction of th PACS Quy tiv Svic by highlighting it. All of th pmts quid fo th initition of DICOM ssocition ith th PACS hv no bn st, nd it only us confimtion by clicking th Nxt button. Stg Fou: Th us clicks th Nxt button ith th lft mous button to confim th slction of th PACS Quy tiv Svic. This is immditly follod by th fist DICOM ctivity. A TCP sssion is opnd, nd ithin it th clint snds DICOM ssocition qust nd th PACS sv sponds ith DICOM ssocition ccptnc (This DICOM ctivity is nlysd byt by byt in sction 3..). Subsqunt to th DICOM ssocition qust bing civd, th Impot Wizd:DICOM Quy tiv Svic (V7.3) : Ptint Slction indo opns in th Eclips disply, s shon in Figu

166 Chpt 3: Infomtion tnsf Fig Subsqunt to th DICOM ssocition qust bing civd, th Impot Wizd:DICOM Quy tiv Svic (V7.3) : Ptint Slction indo opns in th TPS disply. Th Locl Appliction Entity Titl VDCM_E6 is hdid popty of th TPS. Th mot Appliction Entity titl GEPACSD34, is popty of th PACS systm tht is spcifid in th configution of th PACS Quy tiv svic in th TPS, hich is snt to th PACS systm s pt of th ssocition qust. Stg Fiv Th us nts th ptint ID, numic sting, in this cs svn digits NNNNNNN. Th is no DICOM ctivity, bcus th nm hs not bn confimd. Th TPS disply is updtd to sho th unconfimd ntd dt. Stg Six Th us clicks th lft mous button ov th Updt List button to confim th ptint nm. Th clint snds quy tiv t study lvl nd th PACS sv tuns C-FIND SP. Th TPS disply is thn updtd to disply th mtching ptint nm, nd ptint ID. Stg Svn TPS Us Action: Th TPS Us slcts th vilbl ptint nd clicks on th nxt button. Th clint snds quy tiv t study lvl nd th PACS systm snds bck C-FIND SP contining list of vilbl studis fo th slctd ptint. On th bsis of this infomtion, th TPS disply is updtd to sho lyd of th ptint(s) nd vilbl studis. Stg Eight Th TPS Us lft clicks th mous button on th singl vilbl study. Th clint snds quy tiv t study lvl to th PACS. Th PACS snds bck numb of pckts compising C-FIND SP t study lvl, hich contins list of vilbl sis fo th slctd study. Th TPS disply is updtd to disply ths sis s lyd list of th ptint(s), study (studis), nd sis s shon in Figu

167 Chpt 3: Infomtion tnsf Fig Th TPS disply is updtd to sho lyd list of th ptint(s), study (studis) nd vilbl sis, in this MIs. Th ptint nm nd ID hv bn obscud. Stg Nin Th TPS us lft clicks th mous on th quid sis to mk n unconfimd choic of th quid infomtion. As th choic is unconfimd, th is no DICOM ctivity. Th only ction is n updt of th TPS disply to highlight th slctd sis. Stg tn Th TPS us clicks on th >> button to confim slction. Th sulting DICOM ctivity is tht th clint snds quy tiv t img lvl to th PACS sv. Lss thn hlf scond lt, th PACS systm plis ith C_FIND SP contining n A7 Out of soucs o. This is th son tht th to systms ill not communict. Th A7 Out of soucs o is not dscibd in this contxt ithin th PACS DICOM confomnc sttmnt, but it is dfind s mjo fult by th GE DICOM confomnc sttmnt 3. Th clint snds quy, nd th PACS systm plis ith n o. Th TPS disply is updtd to sho lyd list of ptint(s), study(studis), sis nd no imgs on th ight hnd sid of th disply, s shon in Figu Fig Th TPS disply is updtd to sho lyd list of ptint(s), study(studis), sis nd no imgs on th ight hnd sid of th disply. Th ptint nm nd ID hv bn obscud. 45

168 Chpt 3: Infomtion tnsf Stg Elvn Th TPS us slcts sis on th ight pn, mking n unconfimd slction of th sis tht is to b tivd. Th is no ssocitd DICOM ctivity, bcus th choic hs not bn confimd. Th only ction is tht th TPS disply is updtd to sho tht th sis hs bn highlightd. Stg Tlv Th TPS us clicks th lft mous button on th nxt button to confim th slctd sis fo tivl. Th DICOM ctivity tht sults is tht th clint snds DICOM Assocition ls qust to th PACS Sv nd th Sv sponds ith DICOM ls spons. Subsquntly th TPS displys n Impot/Expot Summy indo, s shon in Figu Fig Aft th us slcts th nxt button, th TPS displys n Impot/Expot Summy indo. STAGE Thitn Th TPS Us no slcts th sho dtils button to s hy th imgs could not b lodd. Th is no DICOM ctivity. Th TPS disply opns Log Dtils indo. This indo is blnk gdlss of th slctions md ith gd to ht is displyd. STAGE Foutn Th Eclips us clicks th OK button in th Log Dtils indo. Th sultnt DICOM ctivity is tht th clint snds DICOM Assocition qust to th PACS systm, nd th PACS systm snds bck DICOM ssocition ccptnc. Th Eclips disply gos bck to th img slction stg. STAGE Fiftn Th Eclips us clicks th cncl button to bndon th unsuccssful ttmpt to impot th imgs. Th sulting DICOM ctivity is tht DICOM ls qust is snt by th clint to th PACS sv. Th PACS sv plis ith DICOM ls spons. Th Eclips disply vts bck to th Eclips min indo fom hich th impot izd s initilly lunchd in stg on, s shon in Figu Fig Th TPS disply vts bck to th TPS min indo fom hich th impot izd s initilly lunchd in stg on. 46

169 Chpt 3: Infomtion tnsf It is instuctiv to vi th dsciption of stps -5 nd look t figus to in tun nd not tht ithout th DICOM ctivity dsciption, th is no infomtion in th on scn disply o th soft s tht might llo th us to dtmin hy th tnsf did not ok Summy of th quy/tiv pocss Th PACS spondd to vy img lvl quy fom th TPS ith n out of soucs o. A summy of th DICOM intction tht ld up to this is givn in Tbl Th A-ASSOCIATE-AC mssg snt by th PACS includd notifiction of th PACS ppliction implmnttion clss uniqu idntifi s ; this idntifi is lso spcifid in th PACS confomnc sttmnt nd is uniqu to th PACS. Effctivly in this cs it is digitl fingpint tht povs tht it s th PACS tht snt th out of soucs o. Th snding of th o cod ffctivly mnt tht img tivl s not possibl bcus infomtion on th imgs ithin th PACS could not b obtind. Th TPS fomd n ssocition ith th PACS ith th psnttion contxts, of hich only on, Study oot Quy/tiv Infomtion Modl FIND, s fncd in th subsqunt DICOM infomtion tnsf. Th PACS spondd coctly to quis fncing this psnttion contxt t study nd sis lvl, but lys tund n A7 o hn quid t img lvl. Th ppnc of th A7 o ithin th ishk intfc is shon in Figu An A7 o is dfind by th DICOM stndd in this contxt s n OUT OF ESOUCES o. Th DICOM confomnc sttmnt of th PACS systm 3 only dfins th mning of n A7 o in th contxt of n img bing snt to th PACS by noth ppliction, h it indicts tht th PACS stog o dtbs subsystm is not functioning. Fig Th ppnc of th A7 o in th ishk intfc is th IP numb of th PACS. 47

170 Chpt 3: Infomtion tnsf Snd Action o Mssg Infomtion tnsf summy TPS A-ASSOCIATE-Q PACS A-ASSOCIATE-AC USE Us nts ptint ID TPS C-FIND-Q (Study) PACS C-FIND-SP Quy Ptint Nm tht mtchs Ptint ID. Mtching ptint nm tund. USE Us slcts ptint. TPS C-FIND-Q (Study) PACS C-FIND-SP Quy Study UIDs tht mtch Ptint Nm Mtching study UIDs tund. USE Us slcts study TPS C-FIND-Q (Sis) PACS C-FIND-SP Quy Sis UIDs tht mtch Study UID Mtching sis UIDs tund. USE Us slcts sis TPS C-FIND-Q (Img) PACS C-FIND-SP Quy Img UIDs tht mtch Study UID nd SEIES UID Sttus A7 Cnnot xcut quy TPS A-ELEASE-Q PACS A-ELEASE-P Tbl TPS us, TPS nd PACS squntil infomtion tnsf summy Th ol of th PACS dministto in PACS ollout. A skilld PACS dministto is th singl most impotnt lmnt in PACS ollout 3. Knoldg of th DICOM stndd nd DICOM gp nlysis idly ccptd s impotnt skills fo PACS dministto 3. Dtild knoldg of th quy tiv pocss, nd DICOM toublshooting stndd pt of PACS dministto tining couss 33. At th Alfd Hospitl th PACS dministto s n mploy of th hospitl oking ithin th Dptmnt of dioy, hich took ovll sponsibility fo th n PACS implmnttion. Whn dvisd tht PACS s tuning n A7 o nd th mnings documntd fo tht o in th PACS DICOM confomnc sttmnt, th PACS dministto cknoldgd tht th s comptibility poblm, but fusd to consid th possibility tht th PACS systm could b t fult, guing tht fult in th PACS systm s not possibl bcus oth quy/tiv clints could intct ith it succssfully. Thy nt on to stt tht bcus th fult s not ith th PACS, GE s not quid to povid ny suppot. Th PACS dministto pssd on infomtion fom th GE globl dt bs of noth instnc of comptibility poblm btn th VAIAN quy tiv svic nd th GE PACS tht s nv solvd. Th PACS dministto indictd tht GE hd bn instuctd not to lloct ny futh soucs to th poblm, insisting tht th o must hv bn tund by th VAIAN clint bcus th A7 o s lso documntd ithin th VAIAN DICOM 48

171 Chpt 3: Infomtion tnsf confomnc sttmnt. Th PACS dministto fusd to consid -ctivtion of th old PACS systm, o to giv ny tim fm in hich communiction ith th n PACS systm might b possibl Dtils of th DICOM stndd quy tiv spcifiction. It is ncssy t this point to xplin som dtils of th DICOM stndd spcifiction of th quy/tiv pocss lvnt to th DICOM infomtion xchng. Th quy/tiv svic clss is dfind in Annx C of pt 4 (Svic Clss Spcifictions) of th DICOM stndd. Th VAIAN quy/tiv clint is clssd und th stndd s th svic clss us (SCU), nd th GE PACS is clssd s th svic clss povid (SCP) of th Quy/tiv svic. Th to vilbl infomtion modls spcifid by th stndd fo us ith quy/tiv, th Ptint oot Quy/tiv Infomtion Modl, nd th Study oot Quy/tiv Infomtion Modl. Th ptint oot modl is bsd on fou ti hichy, h ptint (ly ) hs studis (ly ), hich hv sis (ly 3) hich composd of imgs (ly 4). Th study oot modl omits th ptint ly nd so hs only th lys. Attibuts of ptints, such s th ptint nm o th ptint uniqu ID considd to b ttibuts of studis in this modl. Th stndd povids th options fo quy tiv, C-FIND, C-MOVE nd C-GET. Th VAIAN quy/tiv clint uss only th C-FIND option ith study oot modl. An SCU is quid to indict quy tiv lvl (DICOM lmnt 8,5) s pt of ch C-FIND qust. Und th study oot modl th lvl must on of STUDY, SEIES, o IMAGE. Not tht th us intfc of th VAIAN quy/tiv clint pps to b ptint oot hichicl sch, but is implmntd using study oot DICOM infomtion objct dfinition. A C-FIND qust t sis lvl must only sch singl study, so th C- FIND qust must contin infomtion tht uniquly idntifis th study to b schd fo sis. A C-FIND qust t img lvl must only sch sch singl sis ithin study, so th C-FIND qust must contin infomtion tht uniquly idntifis th study nd th sis to b schd fo imgs. Th DICOM stndd lso spcifis quimnts fo C-FIND SP fom n SCP. Th DICOM stndd spcifis tht th SCP must sch th PACS dtbs hichiclly. Fo sis lvl quy, it must fist sch th list of studis to find th study tht is uniquly idntifid in th qust. It must thn sch fo mtchs to th qust only mongst th sis tht blong to tht study. This limits th scop of th sch nd th soucs quid to pfom it. Fo n img lvl quy, th SCP must fist sch th list of studis to find th study tht is uniquly idntifid in th qust. Scondly, th SCP must sch only mongst th sis tht blong to study to find th sis uniquly idntifid in th qust. Finlly, th SCP must thn sch fo mtchs to th qust, only mongst th imgs tht blong to th uniquly idntifid singl sis. This limits th scop of th tst nd th soucs quid to pfom it. Th C-FIND spons is quid to includ sttus. A vlu of A7 dsignts filu to xcut th sch by th SCP, du to lck of soucs. Possibilitis tht th dtbs is inopbl o tht th sch is too lg to b xcutd. If PACS systm tund n A7 o it ould b sonbl to xpct tht th o ould b gd by th PACS. At mting btn th diothpy dptmnt, th dioy dptmnt nd GE, GE sttd tht thy could not find ny A7 o in th PACS fils. GE did g to ccpt infomtion on th o nd gv ssuncs tht thy ould of cous invstigt it. 49

172 3..9 Budgting fo PACS. Chpt 3: Infomtion tnsf A multidiscipliny ppoch is commndd hn plnning th PACS budgt 35. Implmnting PACS systm cn cost mo thn xpctd unlss xtodiny c is tkn hn dvising th budgt 36. Plcing th PACS budgt und th contol of th dioy dptmnt nsus tight coupling to th pimy clinicl uss, so tht finncil pioity ill b givn to ddssing th clinicl quimnts of dioists, hich my b to th dtimnt of thos using PACS ithin th id hospitl. Plcing th PACS budgt und th contol of th infomtion tchnoy dptmnt ill shift th finncil pioity tods dqut hd cpbility t th xpns of clinicl soft functionlity. Th gumnts in fvou of both ppochs 37. Whn I consultd ith th hd of th diothpy dptmnt to dtmin possibl solutions of th poblm, h pointd out tht hil th diothpy dptmnt hd bn ptil sponso of th pvious PACS systm, th dioy dptmnt hd ngotitd ith th hospitl mngmnt dictly to fund th n PACS pojct, nd so diothpy hd no input into th govnnc of th n PACS pojct. 3.. PACS contcts nd DICOM confomnc sttmnts. Typiclly th PACS vndos DICOM confomnc sttmnt foms pt of th contct fo th pojct. Th DICOM stndd pt : Confomnc spcifis ht DICOM confomnc sttmnt is quid to hv in it. Although th choics fo vndos to mk in dtmining ht svics thy ill off nd suppot, ll PACS implmnttion quid to suppot mot quy. Suppot of mot quy quis suppot fo quis t ll lvls of th infomtion modl. Additionlly, suppot of mot quy quis implmnttion of th hichicl sch lgoithm mntiond in sction 3..8 bov, xctly s th DICOM stndd dfins it in pt 4 of th DICOM stndd. Whn I mt ith th hd of th dioy dptmnt, h indictd tht h hd bn givn to undstnd tht it s th y in hich th VAIAN clint soft s mking th quy/tiv tht s cusing th poblm. H sid tht h undstood tht quis fom th VAIAN quy tiv clint ttmptd to sch th nti PACS chiv nd consumd mo mmoy soucs thn ny PACS systm could possibly povid. 3.. Quy/tiv xtndd ngotition Th DICOM stndd lso spcifis n optionl ltionl quy tiv svic vilbl though xtndd ngotition. Th svic is optionl in th sns tht only if both th SCU nd th SCP suppot ltionl quy, nd if it is qustd nd ccptd hn n ssocition is fomd s pt of xtndd ngotition, is th svic quid to b suppotd. Whs in th hichicl sch, lmnts t ll lvls bov th lvl of th quy must b spcifid uniquly, in ltionl quy this stiction is movd. ltionl quis cn includ ny infomtion t ny lvl to b mtchd. Fo ltionl quy, th DICOM stndd dos not spcify th sch lgoithm. PACS systms xpctd to compt to implmnt fst ltionl quis using spcilizd lgoithms. Clus of th n PACS DICOM confomnc sttmnt spcificlly stts tht only hichicl quy is suppotd, no ltionl quy is suppotd. Img lvl ltionl quis cn potntilly b too lg fo PACS to hndl. 5

173 3.. Assocition Ngotition Chpt 3: Infomtion tnsf As mntiond in sction 3.., ll DICOM communictions bgin ith ssocition ngotition. It is instuctiv to vi th dtils of th ssocition ngotition hn th VAIAN Q/ Clint soft foms n ssocition ith th GE PACS. As indictd in tbl 3..6-, th clint snds n A-ASSOCIATE-Q nd th PACS plis ith n A-ASSOCIATE-AC. By viing th contnts of ths to DICOM upp mssg ly lmnts in dtil, it cn b sn hth ny xtndd ngotition took plc to llo th implmnttion of ltionl Q/ svic. It is usful lso s n xmpl to s ht sot of infomtion sniffing th ssocition cn dtmin. Th ASSOCIATE-Q is cid by singl pckt, 37 byts long, shon in Figu Ech lmnt of this pckt is vid blo. Hxdciml vlus givn th suffix H hn mntiond in th txt. Thus th fist byt of th pckt is H. Ech of th fist occuncs of th 8 diffnt icl lmnts of hich th ASSOCIATE-Q is md up ill b listd nd xplind. 5

174 Chpt 3: Infomtion tnsf C 7 AC D 56 7 F C B 94 C 8 AC F9 4 A8 75 F4 5B A DA EA FB D D D 5F E 3 E E E 33 E 3 E 3 E B 3 E 3 E E E 35 E 3 E 34 E 3 E 3 E 3 E E 3 E E E 3 E B 3 E 3 E E E 35 E 3 E 34 E 3 E 3 E 3 E E 3 E E E 3 E 3 E 3 3 E 3 E E E 3 E E 3 E E E 3 E 3 5 D E 3 E E E 37 3 E 3 E 3 E D F 3 3 MAC Hd Itm-typ Intnt Potocol Hd Itm-lngth 3 TCP Hd Appliction-contxt-nm 4 PDU TYPE 3 Psnttion-contxt-ID 5 ESEVED BYTE 4 Abstct-syntx-nm 6 PDU-lngth 5 Tnsf syntx nm 7 Potocol-vsion 6 Mximum lngth civd 8 Clld-AE-titl 7 Implmnttion Clss UID 9 Clling-AE-titl 8 Implmnttion vsion nm Fig Th ASSOCIATE-Q pckt. Ech squ psnts byt fom th byt stm, in od fom lft to ight nd thn don th pg. Ech squ contins hxdciml psnttion of th byt contnts. Ech diffnt colou psnts diffnt icl lmnt ithin th pckt. 5

175 Chpt 3: Infomtion tnsf Fig Elmnt : MAC Hd (Fist occunc byts -4) C 7 AC D 56 7 F C 8 45 Dcoding th MAC Hd ccoding to tbl finds it to b composd of dstintion MAC ddss -- C-7-AC-H, hich is th uniqu six byt ddss of th PACS ntok cd, nd souc MAC ddss -D F-CH, hich is th uniqu six byt ddss of th diothpy ttmnt plnning systm comput. Th lst to byts th Typ fild 8 H to signify tht th ncpsultd dt is n IP pckt. Fig Elmnt : Intnt Hd (Fist occunc byts 5-34) C 7 AC D 56 7 F C B 94 C 8 AC F9 4 A8 75 F4 5B A DA EA FB 5 8 Dcoding th Intnt hd ccoding to tbl 3..3-, Byt 545H givs th IP vsion s 4 nd th lngth of th IP hd s byts in totl. Byt 6 H indicts th Typ of Svic. Byts H indicts 358 byts totl lngth. Byts H givs 595 s th Idntifiction numb of th pckt. Byts - must b intptd t bit lvl: 4 H hich givs Flgs (svd Bit, Not St; Don t fgmnt, St; Mo Fgmnts, Not St) nd Fgmnt Offst. Byt 38H givs th Tim to liv s 8. Byt 46H dsignts th potocol st to TCP. Byts 5-6B 94H givs th Chcksum. Byts 7-3C 8H givs9...9 s th Souc IP Addss. Finlly byts 3-34AC 6 7 H givs s th Dstintion IP Addss. Fig Elmnt 3: TCP Hd (Fist occunc Byts 35-54) 7 4 F9 4 A8 75 F4 5B A DA EA FB D D4 38 Dcoding th TCP hd using tbl 3..- Byts F9H givs 73 s th Souc Pot. Byts H givs 4 s th Dstintion Pot. Byts 39-4A8 75 F4 5BH givs th Squnc Numb. Byts 43-46A DA EA FBH givs th Acknoldgmnt Numb. Byt 475H must b intptd t Bit lvl, h 5 So 5x4 Byts offst, svd. Byt 488H givs th Flgs s ( Congstion Windo ducd (CW): Not St; ECN-Echo: Not st; Ugnt: Not st; Acknoldgmnt: St; Push: St; st: Not st; Syn: Not st; Fin: Not st) Byts H givs th Windo Siz s 75. Byts 5-54D D4H givs th Chcksum. Finlly Byts H sts th Ugnt Point. No options dfind bcus th Byts offst indictly indictd tht th ould b non. Fig Elmnt 4: PDU TYPE (Fist occunc Byt 55) D D4 38 Vlu H indicts tht this is th stt of n ASSOCIATE-Q PDU. (S tbl 9- in pt 8 of th DICOM stndd fo th stuctu of n A-ASSOCIATE-Q PDU, hich govns th intpttion of donstm byts.) Fig Elmnt 5: ESEVED BYTE (Fist occunc Byt 56) D D4 38 Th ASSOCIATE-Q PDU stuctu quis this byt to b snt s H, but civing pplictions quid to igno this byt gdlss of its vlu. 53

176 Chpt 3: Infomtion tnsf Fig Elmnt 6: PDU-lngth (Fist occunc Byts 57-6) D D4 38 Th fou byts 38H spcify lngth of 3 byts fo th mind of th dt in th A-ASSOCIATE-Q PDU. Th ncoding of multi-byt intg in n ASSOCIATE-Q PDU is big ndin, in ccodnc ith clus 9.3. of pt 8 of th DICOM potocol. Fig Elmnt 7: Potocol-vsion (Fist occunc Byts 6-6) D D4 38 Th vlu H spcifis tht th VAIAN DICOM quy tiv pogm suppots vsion of th DICOM Upp Ly potocol. Fig Elmnt 8: Clld-AE-Titl (Fist occunc Byts 65-8) A fixd 6 byt long fild spcifying th clld AE-Titl in ASCII, ith lding nd tiling blnks (H) ignod. Th clld AE-Titl is GEPACSD34. Fig Elmnt 9: Clling-AE-titl (Fist occunc Byts 8-96) D 5F A fixd 6 byt long fild spcifying th clling AE-Titl in ASCII, ith lding nd tiling blnks (H) ignod. Th clling AE-Titl is VDCM_E6. Fig Elmnt : Itm-typ (Fist occunc Byt 9) 5 3 E 3 E E Th vlu of H fo this itm-typ byt dsignts tht th itm folloing is n ppliction contxt itm. This mks th stt of th vibl itms of th ASSOCIATE-Q PDU. Th vibl itms of th ASSOCIATE-Q PDU quid to includ singl ppliction contxt. Fig Elmnt : Itm-lngth (Fist occunc Byts 3-3) 5 3 E 3 E E This to byt intg givs th lngth of th folloing Appliction-contxt-nm. Th vlu is byts. Fig Elmnt : Appliction-contxt-nm (Fist occunc Byts 33-53) 5 3 E 3 E E E 33 E 3 E 3 E Th ppliction contxt nm is , hich dfins vsion of th stndd suppotd s bing tht dscibd in th 9 DICOM stndd (nd oth pvious vsions). Fig Elmnt 3: Psnttion-contxt-ID (Fist occunc Byt 58) 38 E 33 E 3 E 3 E This singl intg is quid to b n odd numb, nd is usd s singl byt cod fo this psnttion contxt in lt dt intchng ft ssocition. Fig Elmnt 4: Abstct-syntx-nm. (Fist occunc Byts 66-9) 3 B 3 E 3 E E E 35 E 3 E 34 E 3 E 3 E 3 E 3 Ths 7 byts dsignt th bstct syntx nm s in ASCII, hich is th Study oot Quy/tiv Infomtion Modl MOVE. 54

177 Chpt 3: Infomtion tnsf Fig Elmnt 5: Tnsf syntx nm (Fist occunc Byts 97-3) 4 3 E 3 E E E 3 E Ths 7 byts compis th tnsf syntx hich is th UID fo Implicit V Littl Endin, hich is th DICOM dfult tnsf syntx. Applictions quid to off nd suppot Implicit V Littl Endin, so th Vin DICOM quy tiv svic is ffctivly offing th minimum llod functionlity. Fig Elmnt 6: Mximum lngth civd (Fist occunc Byts ) 3 E 3 5 D This 4 byt intg spcifis th snding ssocition s (VAIAN s) stiction on th mximum siz in byts of singl PDU tht cn b snt ithin th ssocition. Th vlu st is byts. Fig Elmnt 7: Implmnttion Clss UID (Fist occunc Byts ) 4 3 E 3 E E E 37 3 E 3 E 3 E D Ths tnty byts dsignt th implmnttion clss UID s , hich is not uniqu idntifi dfind by th DICOM potocol. It is dfind in th VAIAN DICOM confomnc sttmnt. It uniquly idntifis th clling soft. Fig Elmnt 8: Implmnttion vsion nm (Fist occunc Byts ) 3 E 3 E 3 E D F 3 3 Ths nin byts spcify th implmnttion vsion nm s VMS DC_. This cn b thought of s th soft nm nd vsion of th VAIAN DICOM quy/tiv clint soft ppliction. Th A-ASSOCIATE-Q thn hs th folloing infomtion contnt. Clld AE_Titl: GEPACSD34 Clling AE_Titl: VDCM_E6 Appliction Contxt: (9 DICOM Stndd) Psnttion Contxt: 5 Abstct Syntx: (Study oot Q/ Modl MOVE) Tnsf Syntx: (Implicit V Littl Endin: DICOM Dfult) Psnttion Contxt: 3 Abstct Squnc: (Study oot Q/ Modl FIND) Tnsf Syntx: (Implicit V Littl Endin: DICOM Dfult) Psnttion Contxt: Abstct Syntx: (Vifiction) Tnsf Syntx: (Implicit V Littl Endin: DICOM Dfult) Us Info Mx PDU Lngth: Implmnttion UID:

178 Chpt 3: Infomtion tnsf Vsion: VMS DC_ This could b loosly tnsltd s Would lik to b bl to b find nd b snt imgs, s ll s un communiction tst, using th dfult DICOM tnsf syntx. Th ASSOCIATE-AC fom th PACS is lso cid by singl pckt, in this cs 93 byts long, shon in Figu Ech n uniqu lmnt of this pckt is vid blo. Hxdciml vlus givn th suffix H hn mntiond in th txt. Thus th fist byt of th pckt is H. Th fist ppnc of ch n uniqu lmnt ill b listd nd xplind blo. 56

179 Chpt 3: Infomtion tnsf D 56 7 F C A 8B 99 E7 FC C E 6 F4 AC 6 7 C F9 A DA EA FB A8 75 F C4 B 8 E D 5F E 3 E E E 33 E 3 E 3 E E 3 E E E 3 E E 3 E E E 3 E E 3 E E E 3 E E 3 E E E 36 E E E F 33 E 3 MAC Hd Appliction-contxt-nm Intnt Potocol Hd 3 Psnttion-contxt-ID 3 TCP Hd 5 Tnsf syntx nm 4 PDU TYPE 6 Mximum lngth civd 5 ESEVED BYTE 7 Implmnttion Clss UID 6 PDU-lngth 8 Implmnttion vsion nm 7 Potocol-vsion 9 non zo svd Byts Itm-typ non zo svd Byts Itm-lngth sult/son Fig Th ASSOCIATE-AC pckt. Ech squ psnts byt fom th byt stm, in od fom lft to ight nd thn don th pg. Ech squ contins hxdciml psnttion of th byt contnts. Ech diffnt colou psnts diffnt icl lmnt ithin th pckt. In od to nsu tht chng in ncoding instuctions is lys ccompnid by chng in colou, h th butting svd gions tht quid to tk diffnt vlus, th non zo svd byts coloud ccoding to th souc of th vlus tht thy must tk. 57

180 Chpt 3: Infomtion tnsf Fig Elmnt 4: Potocol Dt Unit (PDU) typ (Fist ppnc Byt 55) 77 C4 B 8 E9 Vlu H indicts tht this is th stt of n ASSOCIATE-AC PDU. (S tbl 9-7 in pt 8 of th DICOM stndd fo th stuctu of n ASSOCIATE-AC PDU. Fig Elmnt 5: PDU-lngth (Fist ppnc Byts 57-6) 77 C4 B 8 E9 Th fou byts E9H spcify lngth of 33 byts fo th mind of th dt in th ASSOCIATE-AC PDU. Th ncoding of multi-byt intg in n ASSOCIATE-AC PDU is big ndin, in ccodnc ith clus 9.3. of pt 8 of th DICOM stndd. Fig Elmnt 9: svd non zo byts (Fist ppnc Byts 65-8) This svd fild must b st to th vlu of th clld AE-Titl in th ASSOCIATE-Q PDU, but civing pplictions quid to igno th vlu. Th fild is coloud th sm s th clld AE Titl in th ASSOCIATE-Q bcus it is quid to qul tht vlu, nd to diffntit it visully fom th pcding svd byts hich quid to hold NULL vlu. Fig Elmnt : svd non zo byts (Fist ppnc Byts 8-96) D 5F This svd fild must b st to th vlu of th clling AE-Titl in th ASSOCIATE-Q PDU, but civing pplictions quid to igno th vlu. Th fild is coloud th sm s th clling AE Titl in th ASSOCIATE-Q bcus it is quid to qul tht vlu, nd to diffntit it visully fom th pcding svd byts hich quid to hold diffnt vlus. Fig Elmnt : sult/son (Fist ppnc Byt 6) 38 E 33 E 3 E 3 E Th vlu of zo in this singl byt intg indicts ccptnc of th psnttion contxt. Fig Elmnt 5: Tnsf syntx nm (Fist ppnc Byts 66-8) 4 3 E 3 E E E 3 E Ths 7 byts compis th tnsf syntx hich is th UID fo Implicit V Littl Endin, hich is th DICOM dfult tnsf syntx. Applictions quid to off nd suppot Implicit V Littl Endin, so th GE PACS is ffctivly suppoting th dfult tnsf syntx. Fig Elmnt : Itm-typ (Fist occunc byt 83) 3 38 E 3 E Th vlu of H fo this itm-typ byt indicts tht th folloing itm is psnttion contxt ithin n ASSOCIATE-AC PDU. Fig Elmnt 6: Mximum-lngth (Fist occunc byts 49-5) This fou byt intg futh consticts th mximum lngth of P-DATA-TF PDU snt by th ssocition qusto (VAIAN quy/tiv svic) ithin th ssocition to 8,67 byts 58

181 Chpt 3: Infomtion tnsf Fig Elmnt 7: Implmnttion clss uid (Fist occunc byts 57-75) 3 E 3 E E E 36 E E E Ths nintn byts contin th implmnttion clss UID of th ssocition ccpto (Th GE PACS): , hich mtchs th UID found in sction of th GE confomnc sttmnt. 3 Fig Elmnt 8: Implmnttion vsion nm (Fist occunc Byts 8-93) E E E F 33 E 3 Ths foutn byts contin th implmnttion vsion nm of th GE PACS, CENTICITY_3.. Th A-ASSOCIATE-AC thn hs th folloing infomtion contnt. [Clld AE_Titl]: GEPACSD34 [Clling AE_Titl]: VDCM_E6 Appliction Contxt: (9 DICOM Stndd) Psnttion Contxt ply Psnttion Contxt ID: 5 sult: (Accpt) Tnsf Syntx: (Dfult DICOM tnsf syntx) Psnttion Contxt ply Psnttion Contxt ID: 3 sult: (Accpt) Tnsf Syntx (Dfult DICOM tnsf syntx) Psnttion Contxt ply Psnttion Contxt ID: sult: (Accpt) Tnsf Syntx: (Dfult DICOM tnsf syntx) Us Info Mx PDU LEGTH: 867 Implmnttion UID: Vsion: CENTICITY_3. Which could loosly b tnsltd s mssg bck fom th PACS sying I ill suppot quy nd mov instuctions und th ti hichy of study, sis, nd img, nd I ill spond ppopitly to tst (vifiction) cll; ll using th dfult communiction uls. Th n PACS confomnc sttmnt indicts tht th ppliction ntity titls chckd nd jctd if not coct t th tim n ssocition is fomd. Th most common fult in DICOM communictions is tht th DICOM 59

182 Chpt 3: Infomtion tnsf ps not coctly configud ith ch oths ppliction ntity titl nd so fil to fom n ssocition. Th bov sction shos tht n ssocition s fomd nd so th ppliction ntity titls coctly configud. Th months lt GE suggstd tht th fult s du to th ong ppliction ntity titl bing spcifid fo th VAIAN Quy tiv svic OFFIS DICOM Toolkit:FINDSCU Th OFFIS DICOM Tool Kit 39 is collction of libis nd pplictions implmnting lg pts of th DICOM stndd tht is fly vilbl fo don lod 4. In pticul, n ppliction clld FINDSCU is vilbl, hich implmnts svic clss us fo th quy tiv svic clss. FINDSCU cn b usd to tst svic clss povids of th quy/tiv svic clss. Using FINDSCU to tst th spons of quy/tiv svic clss povid in plc of clinicl ppliction is usful fo numb of sons. Fistly, FINDSCU is vy flxibl ppliction. Th commnd lin syntx llos full contol of th mtch citi nd th bility to slct btn th ptint oot o study oot infomtion modl, hich is not lys possibl ith clinicl pplictions. This flxibility llos invstigtion to dtmin th scop of fult. By mking bity chngs in th mtch citi, it my b possibl to dtmin n lmnt in th mtch citi tht povoks th fult. Additionlly, by vying th infomtion modl und hich th quy is md, it my b possibl to dtmin if th fult is stictd to pticul infomtion modl. Th scond us fo FINDSCU is to implmnt locl solution. If y cn b found to succssfully quy th cliniclly quid infomtion using FINDSCU, phps ith slightly diffnt st of mtch citi o und th ltntiv infomtion modl, it my b possibl to quickly build up n ltntiv ppliction bsd on OFFIS pplictions tht my povid th cliniclly quid functionlity. This ppoch is not f ftchd, it ill b dmonsttd in pctic in sction 3.3. It is lso impotnt to not tht OFFIS DICOM Toolkit pplictions fom th bckbon of mny commcil DICOM ltd pplictions. Th thid pupos svd by th us of FINDSCU iss fom th vy fct tht FINDSCU is mtu ppliction 39 ; shoing tht fult psists hn FINDSCU is utilizd dds ight (if not igo) to th suggstion tht th svic clss povid my not b DICOM confomnt. Th mind of this sction summizs 4 spt quis (Q-Q4) md of th GE PACS using FINDSCU. Ths quis md by loding th FINDSCU ppliction on to th Eclips plnning comput nd xcuting th quis fom th commnd lin pompt. Th dstintion pot nd IP ddss spcifid to mtch thos usd by th Q/ svic (VAIAN Eclips DICOM Quy tiv Svic V7.3, Vin Mdicl Systms, Plo Alto, USA); nd sinc th quis md fom th sm comput ith th sm IP ddss, th ntok tffic s idnticl to tht of th clinicl systm fo th MAC ly, IP ly nd TCP ly. This hd th ddd bnfit of nbling th tsting of th PACS systm ithout quiing ny soucs fom th PACS dministto o th hospitl IT dptmnt. Duing ssocition ngotition, hov, diffncs mg s FINDSCU tnsmits diffnt ppliction ntity UID. Th full dsciption of ch quy (givn in ppndix A.3..3-) bgins ith n numtion ccompnid by n xplntoy titl, follod by th xct syntx of th commnd lin FINDSCU quy (Although h ncssy, th ptint UID is psntd s XXXXXXX). Th quy syntx is follod by 6

183 Chpt 3: Infomtion tnsf shot dsciption of th motivtion fo mking th quy tst, hich lso summizs th slint points of th quy configution. DICOM pckt sniffing s usd to dcod th infomtion tht pssd btn th to pplictions, fom hich th mtch quy infomtion contnt nd th PACS ply (if ny oth thn n o mssg) summizd in tbul fomt (Wh ncssy, th ptint nm is psntd s NNNNNN nd th ptint UID is XXXXXXX). Th tbul listing of th mtch quy infomtion is hdd ith stipultion of hth th quy s md und th study oot infomtion modl (Option S in th commnd lin) o th ptint oot infomtion modl (Option P in th commnd lin) Th dsciption of ch quy concluds ith pogssiv nlysis of th obsvd sponss. Folloing quy foutn th sction is concludd by th finl xcpt fom th cod of th ctul incidnt. Quy On: Th fist quy s th simplst, sfst quy of th PACS, mounting to qust of th PACS to find ll studis tht mtchd th ptint ID. It is pliction of th DICOM quy snt to th PACS by th VAIAN DICOM quy/tiv ppliction t stg six of th squntil dtils psnttion in sction 3..5, to hich th PACS spons s knon. Th PACS spondd coctly s xpctd. Quy To: Th scond quy s qust of th PACS to find ll studis fo pticul ptint. Th PACS spondd coctly s xpctd. Quy Th: Confomnc quis tht th PACS must not includ infomtion tht is not qustd. Whn quid in pticul y to find ll th studis fo pticul ptint, th PACS spons includd th ptint ID nd th sis UID, vn though this infomtion s not qustd. This s cl vidnc of th PACS not bing fully DICOM complint. Quy Fou: This tst s inconclusiv. A dlibtly non complint img lvl qust s md of th PACS, nd th PACS tund n o. Quy Fiv to Nin: Ths fiv diffnt but fully complint simpl img lvl quis. Th quy includs spcifid Study UID, nd spcifid Sis UID. Th PACS spondd to ll of thm ith n o. This indicts non complinc to th DICOM stndd. If th PACS cnnot spond to img lvl quis, it is of no functionl us fo tnsfing infomtion to th diothpy systm. Quis Tn nd Elvn: Ths to diffnt, non complint img lvl quis, tid just in cs th PACS ould spond to non complint img lvl quy. Th PACS tund n o mssg in both css. Quy Tlv: This s non complint img lvl quy. Th pupos s n ttmpt to tst hth th PACS s implmnting th mndtd hichicl sch lgoithm, nd if it s not, to ttmpt to xploit this non complinc to obtin img lvl infomtion. Th PACS simply gv n o mssg to this quy, so th ttmpt fild. Th o mssg tund suggstd tht th PACS incoctly ttmptd to xcut ltionl sch. 6

184 Chpt 3: Infomtion tnsf Quy Thitn: To tst if th PACS s implmnting ltionl sch lgoithm, quy s md t sis lvl, ithout ny spcific infomtion bout hich study th sis s in. Und th mndtd hichicl sch, this is non complint quy ith no sult. Th PACS found on sis, sult tht is consistnt ith th PACS implmnting ltionl sch. Quy Foutn: Th finl tst s to includ som img lvl dt in sis lvl quy. Th PACS tund n o, hich is consistnt ith ltionl sch. All ttmpts to obtin img lvl dt fild, nd this md it impossibl to constuct quy tiv t img lvl using FINDSCU s building block. Th fct tht th quis ith FINDSCU lso civd o mssgs fom th PACS povids dict buttl to th onous suggstion tht th PACS s fully DICOM confomnt bcus it could intfc ith ll oth quy tiv implmnttions in th hospitl. All of th obsvtions consistnt ith th PACS bing unbl to hndl img lvl quis bcus it s ignoing th scop of th hichicl quy. This ould mn ll img lvl quis mishndld s quis of th nti dtbs, nd thus too lg to b xcutd ithout n o. If this s th cs, s th siz of th dtbs g, point ould b chd h quis t sis lvl ould fil. This hd potntil implictions fo th potntil suddn filu of oth quy tiv pplictions ithin th id hospitl tht might b lying on sis lvl quy tiv. This did not hlp to solv th poblm dictly, but I s obligd to infom th Dicto of dioy bout th liklihood of this possibility. I snt th hd of dioy n mil outlining th concn tht th PACS might in th n futu fil to spond to quis t sis lvl, suggsting tht fom isk mngmnt point of vi it ould b pudnt to nqui ith th vndo in iting s to ht lmnts of th PACS implmnttion dpndnt upon sis lvl quy. Th hd of dioy cknoldgd ppcition of th concns by mil. 4 On 5/3/8 mo thn th months ft th fult s potd th PACS s obsvd to spond coctly to img lvl quis. No infomtion concning this chng in bhvio of th PACS s civd Aftmth In th k of ths vnts, th finl qustion tht must b ddssd is hy th incidnt occud. Spcificlly, hy s th diothpy cnt ithout ning unbl to quy th PACS systm fo mo thn th months? Th mny contibuting fctos pt fom th non DICOM confomnc of th PACS quy/tiv svic. Th Alfd Hospitl, s n ogniztion, contibutd in not bing cogniznt of th impotnc to th diothpy cnt of th bility to quy tiv imgs fom th pvious PACS systm. Th diothpy cnt could phps hv tid hd to mk th hospitl dministtion of th impotnc of thi ccss to PACS, nd th dioy dptmnt should phps hv bn btt of ho its clints, but th mjo dficincy s in th dministtion of th pvious PACS systm. It is not possibl to st up mot quy svic ithout th cooption of th PACS dministtion, nd th PACS dministtion should hv kpt cods of th mot quy 6

185 Chpt 3: Infomtion tnsf ccss configution of th old PACS nd pssd tht infomtion on to th goup plnning th oll out of th n PACS systm. Although th old PACS systm s mintind in plll to th n PACS systm, ccss to th PACS systm could hv bn monitod fo sidul ccss hich ould hv ltd th PACS instlltion tm to th continud dpndnc of th diothpy dptmnt on th old PACS systm. Th s of cous tchnicl poblm in th DICOM confomnc of th n PACS systm. Th n PACS, s oiginlly instlld, s not DICOM complint. It did not suppot mot quy. It did not implmnt th mndtd hichicl sch. Th svic it did povid ppd to b quivlnt to ltionl quy tiv svic. Th VAIAN quy tiv clint, lthough fully complint fo outin quis, did not hndl th A7 o fom th PACS ppopitly. Th s no infomtion povidd to th us tht th A7 o hd bn civd, nd th VAIAN quy tiv fil did not cod th A7 o, o indd ny vnts t ll in th fild communiction. Th ppliction simply bhvd s if it hd bn skd to impot NULL list of imgs. Th spons of th dition thpist opto to th fult dsvs commndtion. Thy stblishd immditly tht th ptint infomtion xistd in th PACS dtbs, so tht it s vy quickly dtmind tht th clint s quying th ong dtbs. Th Alfd Hospitl PACS dministto, hov, lckd dqut tining. Pckt sniffing nd knoldg of th DICOM potocol both s of xptis tht ftu in PACS dministto couss 33 nd considd impotnt skills fo th PACS dministto to hv ithin th PACS dministto community 3. Th som spcts tht cnnot b solvd, du to n bsnc of qulity infomtion povidd by th vndo. No libl conclusion cn b chd s to hth th PACS contind ny cod of th A7 o. No libl conclusion cn b chd s to ht cusd th non DICOM complinc of th n PACS. It is not knon if th fult s spcific to th sit o fundmntl dsign fl of th PACS oldid. Th fct tht th vndo potd simil poblm t on oth sit suggsts tht th poblm occud t t lst to indpndnt sits. Th continu to b pots of poblms ith quy tiv fo th PACS 4, som uss disstisfid ith th vndo spons 43, but this could b sid of most commcil PACS pplictions, nd this infomtion is not sufficint to suppot conclusion on th scop of th poblm. In summy it ould b fi to sy tht th digitl communiction poblms miod by humn communiction poblms. Th digitl communiction poblms took th months to solv. Th ogniztionl cultu poblms continu to this dy to td th povision of dqut digitl imging mngmnt nd lctonic mdicl cod mngmnt t th Alfd Hospitl 44,45. This poblm is not uniqu to th Alfd, simil poblms hv bn documntd lsh in Austli 46. Th politicl dimnsion of th poblm cnnot b ignod, but th focus of this ok is th tchnicl spct, hich continus in th nxt sction ith n xmpl of n CT scnn unbl to connct to diothpy ttmnt plnning systm. 3.3 CT SCANNE This sction dtils n incidnt h n CT scnn s found to b unbl to communict ith diothpy ttmnt plnning systm. Th CT scnn s th fist in Austli of th pticul modl. Th vndos ch suggstd th non-complinc of th oth s quipmnt. Th s gt dl of pssu to fix th poblm quickly bcus th diothpy ttmnt plnning oklod hd mountd up hil th n CT s bing instlld. 63

186 Chpt 3: Infomtion tnsf 3.3. Objctiv, Pocdus, Equipmnt nd sults Th objctiv s to find out hy CT (Philips 6 slic Billinc id bo CT scnn 47, Philips Mdicl Systms, Clvlnd, OH, USA) could not snd imgs dictly to n TPS (Vin Eclips, Vin Mdicl Systms, Plo Alto, USA). Th ntok tffic btn th CT scnn nd th TPS s monitod using ntok hub nd Linux PC to un tcpdump. Th dptmnt did not t th tim hv ccss to ny lptops. Th PC s n old to unit tht hd bn ittn off th hospitl invntoy. It s movd fom plc to plc on tolly to llo pckt sniffing to b dployd h quid. Additionlly, no ntok potocol nlysis soft s vilbl. Th DICOM dt snt fom th CT scnn to th TPS s xtctd fom th tcpdump output fil by finding vy occunc of 4 contiguous byts tht mtch th infomtion knon to b in th lvnt MAC Hd. Fo ch occunc, using th Hd Lngth nd th totl lngth in th in th IP hd, togth ith th Dt Offst in th TCP hd, it s possibl to find th stt nd finish of th ncpsultd DICOM byt stm fgmnt. Dt s not ppndd to th DICOM byt stm unlss th IP Potocol, Souc IP ddss nd Dstintion IP Addss mtchd. Dt s lso jctd if th TCP Souc Pot nd Dstintion Pot did not mtch th quid vlus. A hx dito 48 s usd to vi th DICOM byt stm. Th DICOM upp mssg ly s dcodd ith fnc to th pts of th DICOM stndd listd in tbl Mny psnttion contxts dfind in th ssocition qust, but only / Computd diogphy Img Stog s fncd by ny DICOM Mssgs snt by th CT scnn. Th only DICOM mssg ly commnd snt by th CT scnn s C-STOE Q hich s dcodd ith fnc to Tbl 9.3- of pt 7 of th DICOM stndd. Th ccompnying CT IMAGE IOD dt s dcodd ccoding to th sctions listd in tbl A.3- in pt 3 of th DICOM stndd. Th complt CT dt fils xtctd fom th cptud ntok tffic, using comput pogm ittn on th Linux c compil to utomt th pocss. Whn th DICOM byt stm s dcodd by inspction nothing unusul s found tht indictd th cus of th poblm, so th dtils omittd, sinc th ppliction of th tchniqu hs ldy bn covd in dtil in sction 3... DICOM CT img fils xtctd fom ntok tffic btn th CT scnn nd th diothpy ttmnt plnning systm. Ths imgs bunt onto CD nd impotd succssfully into th plnning systm. Additionlly, DICOM CT imgs snt fom th CT scnn to PC unning th OFFIS DICOM STOESCP ppliction 4. In ssnc, th ppliction stos DICOM fils snt to it by th C-STOE Q of DICOM p, in this cs th CT scnn. Ths imgs thn snt fom th PC using th OFFIS DICOM STOESCU ppliction 4 to th TPS. In ssnc, th STOESCU ppliction initits C-STOE-Q to tnsmit CT scn s byt stm to DICOM p tht povids th C-STOE svic, in this cs th TPS. Ths imgs succssfully civd nd impotd into th TPS. This s sufficint infomtion to conclud tht th TPS s th cus of th lck of communiction Th nst DICOM ppliction is not lys th cus of th fult. It is oth pointing out t this junctu tht hv to conflicting sults fom th fist to xmpls. In th fist xmpl, n PACS systm s intoducd, nd bcus it s not DICOM confomnt, DICOM quy tiv s no long possibl. Th vndos of th TPS quy/tiv svic md th common sns gumnt tht thi ppliction s unchngd, nd thy could communict ith th old PACS systm, so it must b th n 64

187 Chpt 3: Infomtion tnsf ppliction s fult, th PACS systm s fult, tht thy could not communict ith it succssfully. In this pticul cs thy ight. In th scond xmpl, th old CT scnn s bl to snd CT scns to th TPS, but th n CT scnn could not. Th vndos of th diothpy Plnning Systm stog svic md th common sns gumnt tht thi ppliction s unchngd, nd thy could communict ith th old CT scnn, so it must b th n ppliction s fult, th CT scnn s fult, tht thy could not communict ith it succssfully. In this pticul cs thy ong. Th son hy th nst DICOM ppliction is not lys th cus of th fult is xplind concptully by considing th ntu of DICOM confomnt-limit modl 49. Whn tying to nsu tht ll modlitis communict, ffots to chiv this by poving tht ch ppliction is DICOM confomnt my not succd. Th pplictions ngotit, though th pocss of ssocition, th y in hich svics to b povidd. Th multipl ys to communict th sm infomtion und th DICOM potocol. Whn n ppliction is instlld in ntok, it my xcis cpbilitis of oth DICOM pplictions tht hv not pviously bn quid. In this cicumstnc if th is fult ith th old o th n ppliction (o both o nith) my b sponsibl Cus of th communiction fult. This xmpl s th fist tim tht th dptmnt found DICOM o tht s ssocitd ith th ntok communiction th thn th DICOM fil fomt. Th cpbility to dl ith ths fults hd bn und dvlopmnt ithin th dptmnt fo som tim but ith miniml soucs. Only th cpbility to intcpt th tffic in on diction xistd t th tim tht this fult s obsvd. Th cpbility to vi th tnsction s convstion s not vilbl ith th udimnty tools tht could b dployd. It hs bn conjctud 5 tht th diothpy ttmnt plnning systm s pogmmd ith incoct ssumptions bout th p-dt-tf ncpsultion uls fo DICOM mssgs, nd so ignod som of th tnsmittd fgmnts tht contind th img, nd so obtind n incomplt img s sult of ch nd vy DICOM img tnsf. Th o potd by th TPS s Missing SOP common modul. Th SOP Common Modul is on of th fist goups of tgs includd in th CT fil, nd givs th instnc UID of th img, th sil numb of th img, mong oth lmnts. pots of it not bing psnt consistnt ith th conjctu. 65

188 Chpt 3: Infomtion tnsf Tbl Dcoding th CT Scnn DICOM Upp Mssg ly DICOM Upp ly lmnt lvnt DICOM stndd pt fo syntx Bsic Syntx Big Endin Pt 8 Sction 9.3. A-Associt-Q PDU Pt 8 Tbl 9- Appliction Contxt Itm Pt 8 Tbl 9- Psnttion Contxt Itm Pt 8 Tbl 9-3 Abstct Syntx Sub-Itm Pt 8 Tbl 9-4 Tnsf Syntx Sub-Itm Pt 8 Tbl 9-5 USE INFOMATION ITEM FIELDS Pt 8 Tbl 9-6 MAXIMUM LENGTH SUB-ITEM (A- Pt 8 Tbl D.- ASSOCIATE-Q) IMPLEMENTATION CLASS UID SUB ITEM (A- Pt 7 Tbl D.3- ASSOCIATE-Q) IMPLEMENTATION VESION NAME SUB- Pt 7 Tbl D.3-3 ITEM (A_ASSOCIATE-Q) P-DATA-TF PDU Pt 8 Tbl 9- PESENTATION-DATA-VALUE ITEM Pt 8 Tbl Clinicl Contxt of th CT communiction fult. Du to difficultis ith th instlltion, physics commissioning ccss to th CT scnn s ducd to singl Sundy ftnoon, ithout n pplictions spcilist vilbl. In ddition to udimnty CT QA tsts modld on AAPM pot of tsk goup 66 5, ll of ctivitis dtild in sction 3.3. ccomplishd ithin tht ftnoon nd th quipmnt s vilbl fo schduld clinicl us th nxt dy solution Th CT s tnsmitting CT scn nd th TPS s civing it, but ft th DICOM tnsction s finishd, hn th TPS utomticlly tid to d th DICOM CT imgs into its intnl fomt, it s missing lg pts of th fil nd so potd n o. Th mnufctu undtook to tk coctiv ction so tht th TPS coctly intptd nd stod th infomtion in th DICOM byt stm. It s possibl to implmnt ok ound to commission th CT ith th quid DICOM functionlity on schdul. Th okound s DICOM pt ppliction, s shon in Figu , tht s fully DICOM confomnt nd so bl to civ imgs fom th CT scnn, but tht utomticlly -tnsmittd th DICOM imgs to th TPS in y tht th TPS could coctly intpt. Dict DICOM tnsmission fom th CT to th plnning systm fild bcus th plnning systm did not intpt th DICOM mssg ly dt coctly. Th okound involvd snding th CT scns to ddictd intmdit comput tht could intpt th DICOM mssg ly coctly. Th ppliction s st up simply to snd vy CT slic it civd to th Eclips TPS. Th ppliction s constuctd fom th OFFIS STOESCP nd STOESCU pplictions nd n ndlss loop DOS btch fil. STOESCP s un continuously to sto CT dt fils to nomintd dictoy. Th btch fil put 66

189 Chpt 3: Infomtion tnsf dictoy list into fil, thn d th fil nd clld STOESCU ppopitly fo ch fil to snd it to th TPS. Th vilbl disk spc s limitd (it s n old PC tht s to b disposd of bfo th n CT nt clinicl, gtting id of it s on of th tsks schduld fo th Sundy ftnoon), th tim tkn to tnsmit CT scns fom th CT to th PC ov th ntok s much lss thn th tim tkn to tnsmit fils fom th PC to th TPS, nd it s ncssy to mk su tht no ttmpt s md to snd n img fil tht hd not bn compltly civd. All of ths objctivs chivd by dding slp commnds t diffnt points in th ndlss loop DOS btch fil nd djusting th slp tims by til nd o. Th TPS s bl to intpt th DICOM mssg ly of th OFFIS STOESCU ppliction nd so th tnsmission s succssful. Th CT DICOM stup s configud so tht th ok ound s tnspnt to th uss of th CT scnn, thy simply slctd th spcifid ntok intfc fo tnsmitting dt to th TPS nd th tnsf nt though ithout futh us intvntion. So tht th uss of th CT scnn undstood hy th old PC s quid, nd did not thmslvs tho it out, lbl s ffixd to th sid of th PC dsignting it th CT TPS Dicom Intfc Box, Soft ittn in n ftnoon, unning on comput nobody nts, bought to you by Dodgy Soft Inc.. Th ok ound solution s in us fo mo thn y ithout incidnt bfo it s supsdd by n vsion of th TPS hich s bl to civ dt dictly fom th CT. DICOM diothpy pckt sniffing in this cs llod th implmnttion of solution to th poblm ith locl soucs in th vilbl tim ithout disuption to th clinicl pogm. Dict DICOM tnsmission fils. CT TPS DICOM C-STOE DICOM pt Appliction DICOM C-STOE Fig Th okound solution using DICOM pt ppliction to tnsmit CT dt to th plnning systm. 67

190 Chpt 3: Infomtion tnsf 3.4 diothpy Simulto This sction dtils poblm ith th output of digitl diothpy simulto s ndd by DICOM film pint. Th digitl diothpy simulto hd DICOM pint function, but hn it s linkd to DICOM film pint th sulting output s not scld coctly. This s initilly impotnt cliniclly bcus of dsi to poduc th function of th pvious simulto, hich poducd films of pticul scls Cptu of DICOM dt Th ntok tffic btn th simulto (Acuity, Vin Mdicl Systms, Plo Alto, USA) nd th DICOM film pint (Dypo 75 5, Konic Minolt, Tokyo, Jpn) pint s monitod using ntok hub nd Linux PC to un tcpdump. Th DICOM dt snt fom th simulto to th pint s xtctd fom th tcpdump output fil by finding vy occunc of 4 contiguous byts tht mtchd th infomtion knon to b in th lvnt MAC Hd. Fo ch occunc, using th Hd Lngth nd th totl lngth in th IP hd, togth ith th Dt Offst in th TCP hd, it s possibl to find th stt nd finish of th ncpsultd DICOM byt stm fgmnt. Dt s not ppndd to th DICOM byt stm unlss th IP Potocol, Souc IP ddss nd Dstintion IP Addss mtchd. Dt s lso jctd if th TCP Souc Pot nd Dstintion Pot did not mtch th quid vlus. A hx dito 48 s usd to vi th DICOM byt stm. Th infomtion pcding th img s dcodd by inspction ith fnc to th lvnt sctions of th DICOM stndd. A comput pogm s thn ittn on th Linux c compil to utomt th xtction of th img. Multipl imgs collctd fo diffnt sttings of th pinting configution fil of th cuity simulto Dcoding th simulto DICOM byt stm by inspction Th sctions of th DICOM stndd tht fncd to dcod th DICOM upp mssg ly givn in tbl In this pticul cs th s only on psnttion contxt dfind in th ssocition, / Bsic Gyscl Pint Mngmnt, so ll DICOM Mssgs snt by th simulto fncd tht Infomtion Objct dsciption. Th sctions of th DICOM stndd tht fncd to dcod th DICOM mssg ly givn in tbl Th syntx of th DICOM mssg ly s dfind ithin th ssocition to b th dfult DICOM tnsf syntx, implicit V littl ndin. Tbl D-coding th DICOM Mssg ly fo th simulto DICOM mssg Typ DICOM fnc BASIC GEYSCALE PINT MANAGEMENT N-CEATE-Q (FILM Commnd Pt 7 Tbl.3-9 SESSION) BASIC FILM SESSION N-CEATE ATTIBUTE LIST Dt Pt 4 Tbl H.4- BASIC GEYSCALE PINT MANAGEMENT N_CEATE-Q (FILM BOX) Commnd Pt 7 Tbl.3-9 BASIC FILM BOX N_CEATE ATTIBUTE LIST Dt Pt 4 Tbl H.4-6 BASIC GEYSCALE PINT MANAGEMENT N-SET-Q (IMAGE BOX) Commnd Pt 7 Tbl.3-5 BASIC GEYSCALE IMAGE BOX N-SET-Q MODIFICATION LIST Dt Pt 4 Tbl H.4-68

191 Chpt 3: Infomtion tnsf It s found tht th pint s functioning coctly, but th simulto s not snding coctly scld output. Th dt snt by th simulto s bsic implmnttion of th DICOM pint function. No us s md of th high lvl pixl intpoltion, img scling o nnottion functions vilbl ithin th DICOM Pint svic. Th DICOM pint s simply snt 6 bit img. Scling s implmntd by suounding th img ith hit spc, nd nnottion s implmntd by buning blck pixls into th img. Th img siz s 36.5 MgByts, ith 4,73 os nd 4,7 columns, compd to th ntiv simulto full solution digitl img of,48 by,536 pixls. Th simulto DICOM byt stm bgn ith n ssocition qust, follod by n N-CEATE-Q to ct th film sssion, th pmts of hich givn in tbl Th simulto thn snt N-CEATE-Q to ct bsic film box, th pmts of hich givn in tbl An N-SET-Q s thn usd to spcify th singl img ithin tht box, th pmts of hich givn in tbl Tbl SIMULATO BASIC FILM SESSION N-CEATE ATTIBUTE LIST (Fomt divd fom DICOM pt 4 Tbl H.4-) Attibut Nm Tg Vlu Numb of Copis (,) Mdium Typ (,3) CLEA FILM Tbl SIMULATO BASIC FILM BOX N-CEATE ATTIBUTE LIST (Fomt divd fom DICOM Pt 4 Tbl H.4-6) Attibut Nm Tg Vlu Img Disply Fomt (,) STANDAD\, fncd Film Sssion (,5) 84 BYTES Squnc >fncd SOP Clss UID (8,5) >fncd SOP Instnc UID (8,55) Film Ointtion (,4) POTAIT Film Siz ID (,5) 4INX7IN Mgnifiction Typ (,6) NONE 69

192 Chpt 3: Infomtion tnsf Tbl SIMULATO BASIC GEYSCALE IMAGE BOX N-SET MODIFICATION LIST (Fomt divd fom DICOM Pt 4 Tbl H.4-) Attibut Nm Tg Vlu Img Position (,) Bsic Gyscl Img Squnc (,) 38,9,944 Byts >Smpls P Pixl (8,) >Photomic Intpttion (8,4) MONOCHOME >os (8,) 473 >Columns (8,) 47 >Pixl Aspct tio (8,34) / >Bits Alloctd (8,) 6 >Bits Stod (8,) >High Bit (8,) >Pixl psnttion (8,3) Unsignd Intg >Pixl Dt (7FE,) 38,9,86 Byts solution Th mnufctu of th simulto undtook to coct th simulto DICOM Pint functionlity to scl th output coctly ith th nxt soft updt. Clinicl implmnttion of th full digitl us of th simulto pogssd pidly nd th us of hdcopy imgs s outmodd bfo this chng s md. Th coct output of th DICOM Pint functionlity of th simulto ould thfo only b of potntil bnfit to oth cnts instlling simulto of th sm modl. In this pticul cs, nith DICOM ppliction s fulty. Th Simulto snt DICOM complint pint qust, nd th film pint intptd tht qust coctly in ccodnc ith th DICOM potocol. Th hdcopy film pintd s fithful psnttion of th DICOM dt snt by th Simulto. Th poblm s tht th simulto ppliction soft did not scl its img dt coctly in ccodnc ith its configution fil bfo tnsmitting it. Sinc th img dt tht s snt to th film pint s dtmind by th simulto s quid nd snt immditly ithout stoing it loclly, nd th film pint pintd ll img dt ithout stoing digitl copy, th only y to dtmin tht th simulto s t fult s to us DICOM pckt sniffing to obtin copy of th tnsmittd img nd chck it. 3.5 Discussion Th ng of pplictions fo DICOM pckt sniffing, such s Mg DPM 53, Simns obsv 54, DICOM Tool 55, nd th DVTk 56. DICOM pckt sniffing is fst nd fficint tool fo dtmining hich of to DICOM pplictions is sponsibl hn to DICOM pplictions ill not intct coctly. Th vilbility of ths tools hs no ducd th chllngs Mdicl Physicists fc ith th intoduction of n DICOM pplictions to tctbl lvl. It is no possibl to quickly nd sily ccss th infomtion tnsction tht cuss DICOM fult. This is of considbl ssistnc hn invstigting connctivity issus tht my is du to subtl os in vndos implmnttions of th DICOM stndd. 7

193 Chpt 3: Infomtion tnsf Th potntil poblms ith DICOM intction lmost infinit 57 so it is impossibl to pdict ht pticul knoldg of th DICOM stndd ill b quid to dignos poblm. Fotuntly, th lngth of th byt stm cusing th o ill in most css b mngbl, of th od of hundds of byts. At commissioning, digitl cod should b md of th DICOM byt stm fo ch intfc. If dtild ok instuctions vilbl fo th pfomnc of tsks ssocitd ith infomtion tnsf, ths should b nnottd ith th pckt numbs tht sult fom ch us stp. Such cod is invlubl hn fult is potd. It is not pcticl to nlyz vy DICOM tnsction bfo n o is found, so in pctic nlysis is unlikly to bgin until ft th fult is potd. Th fist stp should b to poduc th fult nd mk digitl cod of th DICOM byt stm communiction involvd. This n cod cn thn b vid togth ith th p-fult pot cod ith fnc to th lvnt sctions of th DICOM stndd to dtmin hich of th pplictions is DICOM confomnt. At th vy lst, th ntu of th fult cn thn b potd dictly to th vndos in tchnicl tms th thn in th lngug of th ppliction uss. Bing bl to tll th vndos tht th PACS systm tund n A7 o in ply to study oot quy qust t img lvl is mo likly to nbl th vndo to solv th o thn tlling th vndos tht th TPS potd tht it could not impot ny of th slctd imgs. This ssums tht th dvic chs vndo psnttiv ith sufficint tchnicl xptis to undstnd it, hich cn b hd to chiv thn solving th oiginl fult. As pcticl xmpl, th A7 o fom th PACS s idntifid ith ishk nd communictd to th vndo ithin dy of th poblm bing potd, hs ks lt th PACS vndo s bst ffots though onsit invstigtions fom dy on still unbl to find ny cod of th o in th PACS fils, by hich tim though DICOM pckt sniffing ll of th lvnt sctions of th DICOM stndd hd ldy bn idntifid, studid nd ssimiltd, nd th oot cus of th fult idntifid nd communictd to th vndo. It is not ncssy to hv n ncyclopdic knoldg of th DICOM potocol to dl ith ths poblms. Th 9 bs stndd hs 6 pts unning to totl lngth of 4,36 pgs. It is sufficint to us th DICOM stndd s fnc hn dcoding th DICOM byt stm. 3.6 Conclusion In this chpt, th hypothss hv bn povd ith spct to DICOM pckt sniffing. In ll th xmpls vid, it s possibl to idntify hich vndo s quid to tk ction to ctify th fult. This is sufficint to stblish tht th is clss of DICOM poblms fo hich th fist hypothsis holds. Th scond hypothsis is povd by th scond xmpl, h th CT scnn could not communict ith th TPS. It s possibl to implmnt n ltnt tnsmission mthod using only loclly vilbl soucs on th sm dy tht th fult s dtctd. Mo gnlly, it ould b xpctd tht mo sophistictd solutions might tk long to implmnt, but might still b implmntd fst thn th vndo cn implmnt n updt. Finding locl solution is not lys possibl, ttmpts to do so in th fist nd thid xmpl fild. Th thid hypothsis is povd by th thid xmpl, ith th DICOM pint. Th simply s no oth y to ccss th infomtion to dcid hth th simulto o th pint vndo s quid to implmnt coctiv ction. Th fist xmpl, ith th PACS systm, hs impotnt implictions fo th DVTk ppoch of xcising ll of DICOM ppliction s functionlity t commissioning to dtmin if it is fully DICOM complint. It is likly tht th PACS ould not hv tund n o fo img lvl quis if it s ccssing smll dtbs. Although it 7

194 Chpt 3: Infomtion tnsf might hv bn slo thn xpctd, th PACS ould pobbly hv schd th hol dtbs to tun th coct ply to n img lvl quy, but this spons ould hv bn constuctd using th ong sch lgoithm. Instd of sching only tiny subst of th dtbs in ccodnc ith th mndtd hichicl sch lgoithm, th PACS ould hv schd vy img in th smll dtbs to obtin th sm sult. Thus no mtt ho much dvlopmnt is put into DVTk, tsting ith DVTk lon ill not b bl to pov tht DICOM pplictions DICOM confomnt. Th stndd of clinicl c in diothpy is dpndnt on th continud function of DICOM communiction. Applying DICOM pckt sniffing to oking intfc is th bst y to ln bout ho th DICOM stndd oks, nd cod of th ntok tffic is n invlubl fnc if intopbility suddnly fils. Commissioning of DICOM cpbl diothpy units should idlly includ coding th DICOM ntok infomtion tnsf fo futu fnc. DICOM pckt sniffing is th bst mthod to dtmin hich ppliction is sponsibl fo th filu of DICOM communiction. Hving dlt in this chpt ith th poblm of infomtion tnsf fom functionl imging modlitis to diothpy pplictions, mov in th nxt chpt to consid th sptil gisttion of functionl imging to th diothpy ttmnt isocnt in th ttmnt oom t th tim of ttmnt. 7

195 Chpt 3: Infomtion tnsf Appndix A OFFIS DCMTK FINDSCU QUEIES GEPACS Q Pliminy tst of FINDSCU connction ith GEPACS findscu -S -k 8, -k 8,3 -k 8,5 -k 8,5STUDY -k, -k,"6478" -k,d -k, -xi -v -t VDCM_E6 -c GEPACSD Motivtion: This quy s th simplst, sfst quy of th PACS, mounting to qust of th PACS to find ll studis tht mtchd th ptint ID. It is pliction of th DICOM quy snt to th PACS by th VAIAN DICOM quy/tiv ppliction t stg six of th squntil dtils psnttion in sction 3..5, to hich th PACS spons s knon. Tbl ASSOCIATED BY STUDY OOT QUEY ETIEVE TAG BYTES NAME DATA (8,) Study Dt NULL (8,3) Study Tim NULL (8,5) Acc Num NULL (8,5) 6 Q/ Lvl STUDY (,) Ptint Nm NULL (,) 8 Ptint ID XXXXXXX (,D) Study UID NULL (,) Study Num NULL Tbl PACS EPLY: Th PACS found on study. TAG BYTES NAME DATA (8,) 8 Study Dt 7 (8,3) 6 Study Tim 5433 (8,5) Acc Num M (8,5) 6 Q/ Lvl STUDY (8,54) A tiv AE GEPACSD34 (8,56) 6 Instnc ONLINE Avilbility (,) 4 Ptint Nm NNNNNNNNNNNNNN (,) 8 Ptint ID XXXXXXX (,D) 34 Study UID (,) 6 Study Num

196 Chpt 3: Infomtion tnsf Although it dos not pp so, this spons is idnticl to tht civd by th VAIAN quy. Th VAIAN quy psnts th quy s ptint oot quy, but implmnts it s study oot quy. In th gphicl us intfc, th infomtion civd tht is dditionl to th ptint nm is simply not displyd. Th cod of th DICOM dt xchng vls fom DICOM pckt sniffing vls tht th to sponss ffctivly idnticl. Q pliction of stg svn findscu -S -k 8, -k 8,3 -k 8,5 -k 8,5STUDY -k,"nnnnnn^nnnn NNNNNNN" -k,"6478" -k,d -k, -xi -v -t VDCM_E6 -c GEPACSD Motivtion: This quy s intndd to plict stg svn of th VAIAN DICOM quy/tiv pocss. Th quy mounts to qust of th PACS to find ll studis fo pticul ptint. Th ptint nm nd th ptint ID both spcifid in th quy. Th PACS is skd to povid th study dt, tim, ccssion numb, Study UID nd Study Numb fo ll studis found. Tbl ASSOCIATED BY STUDY OOT QUEY ETIEVE TAG BYTES NAME DATA (8,) Study Dt NULL (8,3) Study Tim NULL (8,5) Acc Num NULL (8,5) 6 Q/ Lvl STUDY (,) 4 Ptint Nm NNNNNNNNNNNNNN (,) 8 Ptint ID XXXXXXX (,D) Study UID NULL (,) Study Num NULL Tbl PACS EPLY: Found On Study TAG BYTES NAME DATA (8,) 8 Study Dt 7 (8,3) 6 Study Tim 5433 (8,5) Acc Num M (8,5) 6 Q/ Lvl STUDY (8,54) A tiv AE GEPACSD34 (8,56) 6 Instnc ONLINE Avilbility (,) 4 Ptint Nm NNNNNNNNNNNNNN (,) 8 Ptint ID XXXXXXX (,D) 34 Study UID (,) 6 Study Num

197 Chpt 3: Infomtion tnsf Th PACS succssfully povids ll of th infomtion qustd. In th VAIAN gphicl us intfc, only th ptint nm, ptint ID, Study Num, Study Dt nd Study Tim displyd. Th Ptint Accssion Numb, Instnc Avilbility nd Study UID not displyd by VAIAN, but thy psnt in th PACS ply. Not tht th ptint ID uniquly dfins th ptint fncd, so th is no nd fo th ptint nm to b povidd. Th sults indict tht povision of dundnt infomtion dos not cus n o, t lst t study lvl. Q3 Sch fo sis ith miniml infomtion findscu -S -k 8,5SEIES -k 8,6 -k,d k, -xi -v -t VDCM_E6 -c GEPACSD Motivtion: Th PACS is skd to find th sis numb of ll th sis in spcifid study. Th quy is diffnt fom th VAIAN quy in tht it dos not xplicitly quy th Sis UID, only th sis numb. Th intnt is to s if th PACS sponds ppopitly to th scop of th quy. Tbl ASSOCIATED BY STUDY OOT QUEY ETIEVE TAG BYTES NAME DATA (8,5) 6 Q/ Lvl SEIES (8,6) Modlity NULL (,D) 34 Study UID (,) Sis Num NULL Tbl PACS EPLY: Found Svn Sis TAG BYTES NAME DATA (8,5) 6 Q/ Lvl SEIES (8,54) A tiv GEPACSD34 AE (8,56) 6 Instnc ONLINE Avilbility (8,6) Modlity M (,) 8 Ptint ID XXXXXXX (,D) 34 Study UID (,E) 34 Sis UID (,) Sis Num 3 And th oth six sis

198 Chpt 3: Infomtion tnsf This s quy t sis lvl. Th spons of th PACS s th sm s it s to th VAIAN quy, dspit th diffnt infomtion in th qust put to th PACS. Stictly, th ptint ID nd sis UID should not hv bn indictd in th PACS spons sinc thy not quid. It is ppnt t this point tht th PACS is not implmnting DICOM confomnt quy/tiv SCP. Q4: Sch fo imgs ith xt ndom mtch dt t IMAGE lvl. findscu -S -k 8,8 -k 8,5IMAGE -k 8,5 -k 8,55 -k, -k,d k,e k,3 -k 3C,6 -xi -v -t VDCM_E6 -c GEPACSD Motivtion: Th PACS is skd to find ll of th imgs ithin pticul study, ithout ny spcifiction of th sis. This is dlibt non complint quy; th must b uniqu idntifi t ll lvls bov th quy lvl. Additionlly, th quy qust contins som non stndd itms. Th y in hich thy plid to o omittd my indict hth th PACS ctully tks ny notic of th quid itms. Tbl ASSOCIATED BY STUDY OOT QUEY ETIEVE TAG BYTES NAME DATA (8,8) Img UID NULL (8,5) 6 Q/ Lvl IMAGE (8,5) fncd NULL SOP Clss UID (8,55) fncd NULL SOP Instnc UID (,) Ptint ID NULL (,D) 34 Study UID (,E) Sis UID NULL (,3) Img NULL Num (3C,6) fncd Bm Numb NULL 76

199 Chpt 3: Infomtion tnsf Sttus xc Fild: Unbl to Pocss In this quy, n img lvl quy s md ithout sis UID. Th o s diffnt fom A7. Tchniclly, it is DICOM violtion to mk quy ithout spcifid sis UID. Th PACS spons to tun n o is th coct spons. This dos not povid much infomtion on th PACS. Q5 Fully complint, simpl img lvl quy. findscu -S -k 8,5IMAGE -k,d k,e k,3 -xi -v -t VDCM_E6 -c GEPACSD Motivtion: Th intnt of this quy is to simult th clnst possibl qust fo infomtion t img lvl. Th quy includs spcifid Study UID, nd spcifid Sis UID. Th PACS is skd to povid th img numb of ll th imgs in spcifid sis. This is fully complint quy nd th PACS should spond if it is DICOM confomnt. Tbl ASSOCIATED BY STUDY OOT QUEY ETIEVE TAG BYTES NAME DATA (8,5) 6 Q/ Lvl IMAGE (,D) 34 Study UID (,E) 34 Sis UID (,3) Img Num NULL Fild xc Fild: Unbl to Pocss Eo Commnt Unknon pocssing xcption In this quy study UID nd sis UID s povidd, mking this vlid quy. Th PACS could not spond. Th PACS quy/tiv SCP function is not DICOM confomnt. Th cus of th fult is not too much infomtion in th quy, s miniml quid infomtion img lvl quy poducs n o. Q6 Fully complint img lvl img UID quy. findscu -S -k 8,5IMAGE -k,d k,e k 8,8 -xi -v -t VDCM_E6 -c GEPACSD Motivtion: Th intnt in this quy s to tst hth th PACS could spond to n img lvl quy if both th lvls bov uniquly spcifid nd th img uniqu idntifi s quid. 77

200 Chpt 3: Infomtion tnsf Tbl ASSOCIATED BY STUDY OOT QUEY ETIEVE TAG BYTES NAME DATA (8,8) Img UID NULL (8,5) 6 Q/ Lvl IMAGE (,D) 34 Study UID (,E) 34 Sis UID Fild xc Fild: Unbl to Pocss Eo Commnt Unknon pocssing xcption In this quy study UID nd sis UID s povidd, mking this vlid quy. Th img uid s lft blnk. Essntilly th PACS s skd to pot ll th imgs in sis. Th PACS could not spond, hich is futh poof tht th PACS SCP function is not DICOM confomnt. Q7 Img lvl quy of Img UID ith Ptint ID spcifid. findscu -S -k 8,8 -k 8,5IMAGE -k,"xxxxxxx" -k,d k,e xi -v -t VDCM_E6 -c GEPACSD Tbl ASSOCIATED BY STUDY OOT QUEY ETIEVE TAG BYTES NAME DATA (8,8) Img UID NULL (8,5) 6 Q/ Lvl IMAGE (,) 8 Ptint ID XXXXXXXX (,D) 34 Study UID (,E) 34 Sis UID Fild xc Fild: Unbl to Pocss Eo Commnt Unknon pocssing xcption It s thought tht th PACS might b univslly implmnting th ptint oot infomtion modl, vn though th study oot modl s spcifid in th quy. In this quy t img lvl th ptint ID s ddd, nd th PACS still spondd ith n o. This shos tht ddition of ptint ID fild spcifiction in th quy dos not solv th o. 78

201 Chpt 3: Infomtion tnsf Q8 Quy th PACS on singl img. findscu -P -k 8,8 -k 8,5IMAGE -k,"6478" -k,d k,e xi -v -t VDCM_E6 -c GEPACSD Motivtion: Th s suggstion tht th PACS s sching too idly fo imgs, so th PACS s quid t img lvl ith uniqu spcifiction fo th study, th sis, nd th img. Tbl ASSOCIATED BY PATIENT OOT QUEY ETIEVE TAG BYTES NAME DATA (8,8) Img UID NULL (8,5) 6 Q/ Lvl IMAGE (,) 8 Ptint ID XXXXXXXX (,D) 34 Study UID (,E) 34 Sis UID Fild xc Fild: Unbl to Pocss Eo Commnt Unknon pocssing xcption Th sult fom th PACS s n o. Th DICOM potocol quis th PACS to sch hichiclly, fist mong th studis to find th uniqu study spcifid; thn mong th sis tht blong to tht study to find th uniqu sis spcifid; thn mong th imgs tht blong to tht sis to find if on pticul img is psnt. It is not possibl to constucy n img lvl quy tht should qui lss soucs. Th PACS still tuns n o, indicting tht fo htv son, th PACS is unbl to ply to study oot quy t img lvl ith nything mo thn n o. Q9 Minimum scop ptint oot quy t img lvl findscu -P -k 8, k 8,5IMAGE -k,"6478" -k,d k,e xi -v -t VDCM_E6 -c GEPACSD Motivtion: If th PACS cnnot spond coctly to n img lvl quy und th study oot modl, phps it cn spond coctly und th ptint oot modl. 79

202 Chpt 3: Infomtion tnsf Tbl ASSOCIATED BY PATIENT OOT QUEY ETIEVE TAG BYTES NAME DATA (8,8) 34 Img UID (8,5) 6 Q/ Lvl IMAGE (,) 8 Ptint ID XXXXXXXX (,D) 34 Study UID (,E) 34 Sis UID Fild xc Fild: Unbl to Pocss Eo Commnt Unknon pocssing xcption This quy s md using th ptint oot modl, nd spcifid ptint ID s ddd to povidd uniqu spcifiction t ll fou lvls of th modl. This mounts to sking th PACS if it hs th spcifid img in its dtbs. Th PACS should sch fist th ptints to find th singl mtch, thn sch th studis tht blong to th ptint to find th uniqu mtch, thn sch th sis tht blong to th study to find th uniqu sis spcifid, thn sch th imgs tht blong to th pticul uniqu sis to find th spcifid img. If th hichicl sch lgoithm spcifid by th DICOM potocol is implmntd, this sch should consum th lst soucs of ny img lvl quy. Th fct tht th PACS could not spond suggsts tht th PACS cn nv spond to n img lvl quy/tiv. Q Non complint img lvl quy und ptint oot modl. findscu -P -k 8, k 8,5IMAGE -k,d k,e xi -v -t VDCM_E6 -c GEPACSD Motivtion: Th gol h is to mk n img lvl quy und th ptint oot modl ithout ptint spcid, hich is potocol violtion fo ny quy und th ptint oot modl not t ptint lvl. Tbl ASSOCIATED BY PATIENT OOT QUEY ETIEVE TAG BYTES NAME DATA (8,8) Img UID NULL (8,5) 6 Q/ Lvl IMAGE (,D) 34 Study UID (,E) 34 Sis UID Fild xc Fild: Unbl to Pocss Eo Commnt Unknon pocssing xcption This quy omits th ptint spcifiction, hich is potocol violtion, bcus th quy is md und ptint oot. Th PACS tuns n o, hich is th coct spons. 8

203 Chpt 3: Infomtion tnsf Q Scoplss img lvl quy findscu -P -k 8, k 8,5IMAGE -xi -v - t VDCM_E6 -c GEPACSD Motivtion: This quy is intndd to dtmin if th PACS tks ny ccount of mtch dt t lvls bov th lvl of th quy to stict th scop of th sch. Tbl ASSOCIATED BY PATIENT OOT QUEY ETIEVE TAG BYTES NAME DATA (8,8) Img UID NULL (8,5) 6 Q/ Lvl IMAGE Fild xc Fild: Unbl to Pocss Eo Commnt Unknon pocssing xcption This quy is bsiclly sking th PACS to pot th UID of vy img tht it hs. Th PACS tuns n o, hich is th coct spons, but is consistnt ith th PACS ignoing sch scop instuctions nd tying to sch th hol dtbs vytim it hs n img lvl quy. Q Sis lvl quy qusting dt t img lvl und th ptint oot modl. findscu -P -k 8, k 8,5SEIES -xi -v - t VDCM_E6 -c GEPACSD Motivtion: Th im h is to tst if th psnc of n img lvl infomtion qust in sis lvl quy ill cus n o. Tbl ASSOCIATED BY PATIENT OOT QUEY ETIEVE TAG BYTES NAME DATA (8,8) 34 Img UID (8,5) 6 Q/ Lvl SEIES Th PACS plis to this quy ith Sttus A7 Cnnot Excut Quy mssg. This suggsts tht th thn jcting th quy s non complint quy und th hichicl sch lgoithm, th PACS ttmptd sch of vy img in th dtbs nd fild di to th sch scop bing to lg. This ould b ppopit bhvio if th PACS s implmnting ltionl quy. ltionl quis suppotd und DICOM, but only s sult of xtndd ngotition btn th DICOM PEES t ssocition stg, nd no such ssocition occud ith 8

204 Chpt 3: Infomtion tnsf PACS, ith ith th VAIAN o th OFFIS ppliction. Additionlly, th GE PACS confomnc sttmnt stts tht th PACS dos not suppot ltionl quis. Q3 Non complint sis lvl quy. findscu -S -k 8,5SEIES -k,e xi -v - t VDCM_E6 -c GEPACSD Motivtion: To tst if th PACS is implmnting ltionl sch lgoithm, ply is quid fom th PACS. This quy is md t sis lvl. By omitting ny spcifiction t th Study lvl, th quy is n invlid hichicl quy, but vlid ltionl quy. Th PACS is knon to hv pviously spondd coctly to sis lvl quis. Tbl ASSOCIATED BY STUDY OOT QUEY ETIEVE TAG BYTES NAME DATA (8,5) 6 Q/ Lvl SEIES (,E) 34 Sis UID Tbl PACS EPLY: Found On Sis TAG BYTES NAME DATA (8,5) 6 Q/ Lvl SEIES (8,54) A tiv GEPACSD34 AE (8,56) 6 Instnc ONLINE Avilbility (,) 8 Ptint ID XXXXXXX (,D) 34 Study UID (,E) 34 Sis UID This quy s sis lvl quy, ithout spcifid study uniquly dfind. Th PACS s skd to sch fo study tht contind spcific sis. Th PACS should tun n o if implmnting th quid hichicl sch lgoithm. Th dt tund is consistnt ith th GE PACS implmnting ltionl quy. So this is consistnt ith ltionl sch, not hichicl sch. Th inbility to pocss n img lvl quy du to lck of mmoy is lso consistnt ith th GE PACS onously xcuting ltion quy hn it should b xcuting hichicl quy. 8

205 Chpt 3: Infomtion tnsf Q4 Sis lvl quy ith Img lvl dt. findscu -S -k 8,8 -k 8,5SEIES -k,e xi -v -t VDCM_E6 -c GEPACSD Motivtion: Th ddition of th img UID to th sch list of sis lvl quy tsts hth it is th lvl of th quy o th psnc of img lvl dt tht povoks th A7 o fom th PACS. Tbl ASSOCIATED BY STUDY OOT QUEY ETIEVE TAG BYTES NAME DATA (8,8) Img NULL UID (8,5) 6 Q/ Lvl SEIES (,E) 34 Study UID Th PACS sponds ith n A7 Out of soucs o. This is futh vidnc tht th PACS is implmnting ltionl sch. Th psnc of n img lvl lmnt in th quy is sufficint to povok th PACS to tun n o, hich it dos not othis do t sis lvl. 83

206 Chpt 3: Infomtion tnsf (fncs) Amicn Assocition of Mdicl Physicists (AAPM). pot No A stndd fomt fo digitl img xchng. N Yok:, Amicn Institut of Physics Publishing, 98. Cdduck TD, Bily DL, Hutton BF, t l. A stndd potocol fo th xchng of nucl mdicin img fils. Nucl Md Commun 989;: Ntionl Elcticl Mnufctus Assocition (NEMA). Digitl Imging nd Communictions in Mdicin (DICOM). osslyn VA:NEMA, 8. 4 Oskin M, Sibt JA, Knndy L. Dignostics nd ccptnc tsting fo DICOM ntoks: Puchsing of DICOM dvics. In Sibt JS, Filipo LJ, Andiol KP. (Ed.) Pcticl digitl imging nd PACS. Mdison, WI: Mdicl Physics Publishing, 999; Dunds D. Instlltion of PACS systm. B J diol 5;78: Obugh A, Mois G, Wnick E, miz G. Ethl pckt sniffing. ocklnd, MA: Syngss; 4. 7 Bidgood WD, Hoii SC, Pio FW, Vn Syckl DE. Undstnding nd using DICOM, th Dt Intchng Stndd fo Biomdicl Engining. J Am Md Infom Assoc 997;4: Hms Mdicl Solutions [hompg on th intnt]. Stockholm, Sdn: Hms Mdicl Solutions; [citd Aug 5]. Avilbl fom 9 Güld MA, Kohnn M, Kyss D. t l. Qulity of DICOM hd infomtion fo img ctgoiztion. Poc SPIE ; 4685:8-87. Bntzn SM. Thgnostic imging fo dition oncoy: dos-pinting by numbs. Lnct Oncol 5;6:- 7. Intnt Engining Tsk Foc. FC: 793 Tnsmission contol potocol [Mmondum of th Intnt Engining Tsk Foc]. Intnt Engining Tsk Foc; [updtd 98 Sp; citd Oct 6] Avilbl fom: ftp://ftp.fc-dito.og/in-nots/fc793.txt. Intnt Engining Tsk Foc. FC: 79 Intnt potocol [Mmondum of th Intnt Engining Tsk Foc]. Intnt Engining Tsk Foc; [updtd 98 Sp; citd Oct 6] Avilbl fom: ftp://ftp.fcdito.og/in-nots/fc79.txt. 3 Cf VG, Khn E. A Potocol fo Pckt Ntok Intcommuniction. IEEE Tnsctions on Communictions. 974;: Stvns W, TCP/IP Illusttd, Volum Th Potocols. Boston:Addison Wsly, Ntok Socy Inc. Ntok Socy: Ntok communictions [hompg on th intnt]. Sn Digo, CA:Ntok Socy Inc.;[citd Jul 8]. Avilbl fom 6 ivbd Tchnoy. Wishk [hompg on th intnt]. Sn Fncisco, CA:ivbd Tchnoy;[citd Jul 8]. Avilbl fom: 7 Snds C. Pcticl Pckt Anlysis:Using Wishk to Solv l-old Ntok Poblms. Sn Fncisco CA:No Stch Pss, 7. 8 Tcpdump [hompg on th intnt]. [citd Jul 8]. Avilbl fom 9 [citd July 9] Avilbl fom: Sptmb/7.html. Intntionl Ognistion fo Stnddiztion. Intntionl stndds fo businss, govnmnt nd socity [hompg on th Intnt]. Gnv: Intntionl Ognistion fo Stnddiztion; [citd Oct 6]. Avilbl fom Cook N. Toublshooting PACS communictions. Austls Phys Eng Sci Md 8;3: Bsly JS. Ntoking, Sddl iv,nj:pson Pntic Hll, 4;47. 3 Nthn MD. PACS byond dioy. Dvloping tnd spcifictions fo cnc hospitl. Int Cong S 5;8:-4. 4 Sim LH. Budgting fo PACS. Biomd Imging Intv J [sil on th intnt].8 Aug 6 [citd Oct 6];4(4):[bout 7 pgs]. Avilbl fom 5 Fy GD. A PACS Cs Study PACS Dvlopmnt t Th Mdicl Univsity of South Colin. In Sibt JA, Filipo LJ, Andiol KP. (Ed.) Pcticl Digitl Imging nd PACS. Mdison, WI:Mdicl Physics Publishing, 999: Liu BJ, Co F, Zhou MZ, Mogl G, Documt L. Tnds in PACS img stog nd chiv. Comput Md Imging Gph 3;7: Shilds T. PACS: Pst, psnt nd futu. diol Tchnol ;8: Dptmnt of Humn Svics, Victoi, Austli. Humn Svics Ns Novmb 5 [hompg chivs on th intnt]. Mlboun, Victoi, Austli:Dptmnt of Humn Svic, Victoi, Austli; [updtd 5 Nov 8; citd Oct 6]. Avilbl fom 84

207 Chpt 3: Infomtion tnsf (fncs) 9 Hlm J, Hud W. Mdicl physicists should ssum PACS sponsibilitis. Md Phys ;9: GE Mdicl Systms Infomtion Tchnois. Cnticity TM PACS Vsion 3. DICOM CONFOMANCE STATEMENT , EV..9, 5 [hompg on th Intnt]. Gnl Elctic Compny; [updtd 5 Nov; citd Oct 6]. Avilbl fom 3 Bid LC. Th Impotnc of pictu chiving nd communictions systm (PACS) mng fo lg-scl PACS instlltions. J Digit Imging 999;: Ngy P, Bos G, in BI, Sigl EL. Dfining th PACS pofssion: n initil suvy of skills, tining nd cpbilitis fo PACS dministtos. J Digit Imging 5;8: dioicl Svic Tining Institut. Tining Indx [hompg on th intnt]. Solon, OH: dioicl Svic Tining Institut; [citd Aug 3]. Avilbl fom: 34 Chidly J. E: N GE PACS fulty [onlin]. Emil to Tvo Ackly (Tvo.ckly@bc.og.u) 7 Nov [citd Oct 7]. 35 Gytos D, Spzil J, Bmson, Tvs ST. Th PACS p-implmnttion pocss t mjo tching hospitl: A multidiscipliny ppoch. Jounl of Mdicl Imging 3;6: ddy AS, Loh S, Kn A. Budgt vinc nlysis of dptmntid implmnttion of PACS t mjo cdmic mdicl cnt. J Digit Imging 6;9: Chnnin DS, Bos G, Ngy P. Should dioy IT b Ond by th Chif Infomtion Offic?. J Digit Imging 9;: Chidly J. Q/ Vin PACS [onlin]. Emil to Tvo Ackly (Tvo.Ackly@bc.og.u) 8 Fb [citd Oct 7]. 39 Eichlbg M, ismi J, Wilkns T, Htt AJ, Bth A, Jnsch P. Tn ys of mdicl imging stnddiztion nd pototypicl implmnttion: th DICOM stndd nd th OFFIS DICOM toolkit (DCMTK). Poc SPIE 4;537: OFFIS institut fo infomtion tchnoy. DCMTK DICOM Toolkit [hompg on th Intnt]. Oldnbug, Gmny:OFFIS institut fo infomtion tchnoy; [updtd M 3; citd Oct 6]. Avilbl fom: 4 Thomson K. E Q/ Vin PACS [onlin]. Emil to Tvo Ackly (Tvo.Ackly@bc.og.u) 8 Fb 4 [citd Oct 7]. 4 ClCnvs. ClCnvs Community Foums :Foums > Us > Woksttion: Unbl to pfom DICOM tiv fom GE Cnticity PACS 3. [hompg on th Intnt]. Toonto, ON, Cnd; ClCnvs; [updtd Ap 3; citd Oct 6]. Avilbl fom: 43 Knopk A. GE Cnticity PACS 3. quy filu [hompg on th Intnt] mofl.nt:comp.potocols.dicom Digitl Imging nd Communictions in Mdicin [updtd 9 Jun 8; citd Oct 7] Avilbl fom : 44 Mill J. E: John McMhon s concns [onlin]. Emil to Tvo Ackly (Tvo.Ackly@bc.og.u) My [citd My ]. 45 ood D. Computs could cus dths, n doctos. [hompg on th intnt] Mlboun, Austli: Fifx Mdi; Jul 6 [updtd Oct 8; citd Oct 8]. Avilbl fom: 46 Ecksly N.Botchd soft upgd poducs mss X-y filu[hompg on th intnt]. Mlboun, Austli: Pivt Mdi Pty Ltd; [updtd My 8; citd Oct 7]. Avilbl fom 47 Wood, Mutic S, Hmpton C, Lo D. Img Qulity nd Dos Chctistics of N 85-cm multislic CT scnn: A compison study. Md Phys 5;3: Kibi. Fhd F hx dito [hompg on th Intnt]. Fifx, VA: Gknt Inc.; [updtd 9 Jun 5; citd Oct 8]. Avilbl fom: 49 Oskin M, Sibt JA, Knndy L. Dignostics nd Accptnc Tsting fo DICOM ntoks Expincs t th Univsity of Clifoni, Dvis Mdicl Cnt. In Sibt JA, Filipo LJ, Andiol KP. (Ed.) Pcticl Digitl Imging nd PACS. Mdison, WI:Mdicl Physics Publishing, 999: Gtly A. Philips Billinc CT [onlin]. Emil to Jim Cmb (Jim.Cmb@ptmc.og) 7 Jn 6 [citd Oct 8]. 5 Mutic A, Plt J, Butk EK, t l. Qulity ssunc fo computd-tomogphy simultos nd th computdtomogphy-simultion pocss:pot of th AAPM dition Thpy Committ Tsk Goup No. 66. Md Phys 3;3:

208 Chpt 3: Infomtion tnsf (fncs) 5 JZ Imging nd Consulting. Konic Dy Po 75 [hompg on th intnt]. Willoughby, OH: JZ Imging nd Consulting; [updtd Jul 8; citd Oct 8]. Avilbl fom: 53 Dicomnlys. Mg DPM [hompg on th intnt] UK:Dicomnlys [citd 8 Jun ]. Pviously vilbl fom: 54 Ntok Instumnts LLC. Obsv DICOM: Potocol Anlysis fo th Mdicl Industy [hompg on th Intnt] Minntonk, MN:Ntok Instumnts LLC [updtd 6 Ap 5; citd Oct 8]. Avilbl fom: 55 DICOM Tool Ltd. DICOM Tool PACS quisit [hompg on th Intnt]. Shnyng, Lioning, Chin: DICOM Tool Ltd. [citd Oct 8]. Avilbl fom 56 Pott G, Bushbidg, Tolnd M, Ngy P. Msting DICOM ith DVTk. J Digit Imging 7; Suppl : Vn Doon T. Book vi: Pcticl Digitl Imging nd PACS. Austls Phys Eng Sci Md ;3:

209 Chpt 4: gisttion to th ttmnt isocnt Chpt 4 gisttion to th ttmnt isocnt ho cn you possibly d pizs hn vybody missd th tgt? sid Alic. Wll, sid th Qun, Som missd by mo thn oths, nd hv fin noml distibution of misss, hich mns cn fogt th tgt Lis Coll, Alic s Advntus in Wondlnd Contnts 4. PET dt co-gisttion in th diothpy ttmnt oom Pticul cicumstncs in th diothpy ttmnt oom vi of ys to position th ptint Plption of bony lndmks Tttoos nd skin mks Mgvoltg Potl Imging Gnty mountd in oom kilovoltg imging In oom Mgvoltg Con bm CT In oom kv con bm CT In oom dignostic CT In oom Ultsound Implntd fiducils Implntbl dio tnsponds Msuing to ptint sufc Ptint Fixtion otting th ptint out of th hoizontl pln Summy of ptint positioning IGS (ExcTc, BinLb AG, Fldkichn, Gmny) IGS componnts IGS x-y sub systm IGS Opticl sub systm IGS clinicl pocdu IGS scintific pots Phntoms vs Ptints: Hypothss Coodint systms dfinition igid l old coodint systm otting couch bsd coodint systm ltionship btn l old nd couch bsd coodint systm l old coodint systm spcifiction of kv bm ointtions Dfinition of igid coodint systm lignd to th kv bm gomty Soft output

210 Chpt 4: gisttion to th ttmnt isocnt OTATION Th mthod of infnc Clinicl Ttmnt gim Clinicl Dt St sults of Infnc Vition of ccucy ith pss conditions Filting th clinicl dt, scop, nd ssumptions Vition of pss tio ith pss conditions Vition of mximum pss tio ith pss conditions Estimt pss t using post coctionl pss t Dtmining th pss t fo lxd pss citi Vition of sigm fo tightnd pss citi Vition in sptil ccucy ith tightnd pss citi Vition of ccucy ith numb of coctions Bsic pss t Pobbility distibution cuvs fo initil stups Pobbility distibution cuvs fo post ottionl subgoups Clinicl modifictions indictd by obsvd vition Concluding mks on multipl coctions Vition ith distnc movd ST vition ith distnc movd SS Gphs Lg distnc tnsltion in ST Compison of long nd shot coctions Tbultion of lin fits Null sult Fction vition solution of mbiguous fction numbs Vition of sigm ith fction numb Vition of significnc nd diffnc ith fction split Vition of sptil ccucy btn fist to fctions nd globl ST vg Atfcts of msumnt Couch ottion dpndnt fctos: ffct of couch offst Couch ottion dpndnt fctos: initil gdint mthod Automtd optimiztion mthods Optimiztion sults Dict msumnt of offsts Couch ottion indpndnt fctos: nlysis of tipls nd qudupls Expctd sults fom pfct dtmintion of IGS ccucy Angl slf consistncy Conclusion Fist hypothsis: IGS hs dqut sptil ccucy Scond hypothsis: IGS clinicl ccucy cn b infd Thid hypothsis: Clinicl infnc vls mo thn phntoms Fouth hypothsis: Chngs in Clinicl Tchniqu Fifth hypothsis: Diminishing tuns fom tightnd pss citi Sixth hypothsis: Effct of coction distnc on ccucy Svnth hypothsis: Effct of numb of coctions on ccucy Eighth Hypothsis: Effct of fction numb on ccucy

211 Chpt 4: gisttion to th ttmnt isocnt Ninth hypothsis: Angul ccucy cn b infd Tnth hypothsis: Estimtion of tfcts flction Appndix A Th stndd dvition of λ MAX Appndix A MATLAB TEST OF COVAIANCE FOMULA Appndix A Exct binomil tst... 9 Appndix A Mont Clo clcultion mthod fo o bs Appndix A Mtlb cod: figu Appndix A Mtlb cod: figu Appndix A Mtlb cod: figu Appndix A.4..- Mtlb cod: figu Appndix A.4..- Mtlb cod: figu Appndix A Mtlb cod: figu Appndix A Mtlb cod: figu Appndix A Mtlb cod: figu Appndix A Mtlb cod: figu Appndix A Mtlb cod: figu Appndix A Mtlb cod: figu Appndix A Fction numb nomly solution Appndix A Lin ng optimiztion... 3 Appndix A To pmt sch... 3 Appndix A Mont Clo optimiztion fncs PET dt co-gisttion in th diothpy ttmnt oom. W s in chpt on th mgnc of th cunt thms of functionl imging in chin of dpndnc in diothpy;. Th s contovsy ov th thshold of significnc to us in sgmnting tumous using functionl imging.. Th is poblm ith th communiction of functionl imging dt in timly, pcticl nd usful y fo us in dition Oncoy 3. Th is n mging nss of th poblm ith th cogisttion of functionl imging dt to th diothpy ttmnt isocnt in th ttmnt oom. In this chpt consid th thid of ths chllngs, th poblm of cogisttion to th ttmnt isocnt. All th of ths poblms vitl, th is no point to th us of functionl imging fo tumou volum mking if do not kno th thshold of significnc to us to sgmnt tumou, but hving th cpbility to libly sgmnt th tumou volum is of no us unlss cn communict tht infomtion, o th img dt quid to obtin it, 89

212 Chpt 4: gisttion to th ttmnt isocnt into diothpy ttmnt plnning systms. Evn givn ths to ccomplishmnts, still qui confidntly to b bl to position n isocnt ithin ptint t th diothpy ttmnt oom in gisttion ith th functionl imging in od to b bl to utiliz th infomtion tht hv obtind nd intptd fo th dvntg of th ptint s ttmnt. W bgin by xploing th nvionmnt in hich th solution must b implmntd, th diothpy ttmnt oom. Thn vi th diffnt mthods vilbl to position th ptint ttmnt isocnt und img guidnc. Thn no ou focus to pticul img guidnc systm (IGS) implmnttion tht offs ffodbl spd nd ccucy in th plcmnt of th isocnt (ExcTc, BinLb AG, Fldkichn, Gmny). W -xmin th quimnts of th gisttion poblm in th contxt of th IGS, nd stt th hypothss ill pov in spct of it. W continu ith som pptoy dsciptions of coodint systms. Thn stblish th mthod of sttisticl infnc tht ill us to pov th ccucy of th IGS in clinicl pctic. W dscib in tun th clinicl ttmnt pocdus implmntd ith this systm, nd th clinicl dt st colltd fom th implmnttion of th gim. Ou sults commnc ith th gnl sults of infnc on th full dt st, nd pogss to xmin in tun th ffcts of th pss conditions st, th numb of ittiv isocnt coctions pplid ith th systm, th distnc movd in thos coctions, th numb of idnticl ttmnt sssions th ptint hs, nd tifcts of th mthod of infnc. Fo compltnss, xmin th sults of dtmintion of th ccucy of th ointtion ptint. W conclud by viing th sults stblishd ginst th hypothss povd, nd xploing th implictions of th poof of thos hypothss. W do not in this chpt consid th poblm of spitoy motion compnstion. It is n ctiv of sch tht civs substntil ttntion fom oth invstigtos. It is bnficil fo som ttmnts, but not fo ll, nd it lis outsid th scop of this ok. 4. Pticul cicumstncs in th diothpy ttmnt oom. Incsingly, functionl imging fo diothpy involvs hybid imging, ith CT/PET combind scnn, o CT-SPECT 3 combind scnn. In this cicumstnc, much ffot hs bn xpndd to povid gisttion of functionl nd ntomicl imging 4 vn to th xtnt of compnsting fo spitoy motion 5,6. This gisttion of th functionl imging to th dignostic CT scn is of limitd us fo diothpy ttmnt unlss infomtion fom th dignostic CT scn cn b usd to ccutly position th dition ttmnt isocnt. Th is ly CT scnn vilbl in th ttmnt oom to tst th lignmnt of th ptint, nd lthough pototyp 7 nd commcil 8 in oom CT scnns xist, th povision of such quipmnt is xpnsiv. Whn th lin cclto is usd fo ttmnt th CT is idl, hn th CT is usd to chck positioning th lin cclto is idl. diothpy ttmnt of on ptint cn involv 3 spt dily visits o fctions, nd th vilbility of diothpy ttmnt units is th citicl souc in diothpy ttmnt cpcity. Th ptint must b positiond quickly, ccutly, nd conomiclly. It is impotnt to undstnd th son fo th nd to position th ptint ccutly in th diothpy ttmnt contxt. Th diothpy ttmnt units thmslvs cpbl of dliving mo ccut nd confoml 9

213 Chpt 4: gisttion to th ttmnt isocnt ttmnts though th us of multilf collimtos 9 implmnting IMT. A limiting sptil solution of btn.5-3 mm pplis to th bm dg, but th tchnicl poblms lting to sub millimt plcmnt nd dynmic contol of th fild dg, shp nd intnsity hv ll bn solvd. Th cunt limiting fcto in diothpy is thus th bility to dtmin nd mintin th ptint nd tumou position 3,4. 4. vi of ys to position th ptint. Th bility to position th ptint nd th tumou hs lys bn fundmntl undpinning cpbility of diothpy 5. W no vi th volution of th vious mthods of positioning th ptint. 4.. Plption of bony lndmks. Pio to th vilbility of in oom imging, ptints positiond by dition thpists fling ith thi fings th position of, fo xmpl, th stnl notch, s lndmk fo positioning ptints 6. Fo som diothpy ttmnts fo hich this mthod s usd os of gt thn mm occud fo 45% of th ptints 7, bcus no llonc fo intnl position vition could b md. 4.. Tttoos nd skin mks Skin mks md t th tim nd plc of th dignostic CT cquisition. Just s fo plption, this mthod md no llonc fo intnl motion, nd ccucy could b futh dgdd by motion of th skin ltiv to bon 8. dundncy of mks nt som y to ducing this ffct; if th ptint hd to ltl skin mks subsqunt disgmnt t th ttmnt oom s gnlly solvd by positioning to th vg position Mgvoltg Potl Imging Mgvoltg potl imging uss th ttmnt bm itslf to tk n img of th ptint fom th diction of ttmnt to vify tht th ptint is in th coct ttmnt position. Th mgvoltg bm intcts pimily by th compton ffct, nd in consqunc th img qulity is poo 9, gnlly only i cvitis cn b visulizd ith dignostic imging clity. Bon shdos my b pooly dfind but sufficintly visibl to llo vifiction of ccut bm lignmnt. Doubl xposu pot films cn b usd ith th ttmnt potl nd lg fild bing usd, this hs th dvntg of imging th ttmnt bm outlin nd bony lndmks tht outsid th ttmnt fild. Th min disdvntgs th poo img qulity nd th xt dos to th ptint. Whn film is usd s th img mdium, th dly fo dvlopmnt of th film is mjo disdvntg tht tds ptint thoughput nd dgds ccucy s th ptint ill mov hil th film is bing dvlopd. Evn ith th us of lctonic potl imging nd utomtic mtching, mny cnts still choos to implmnt offlin vi 3 ; h th mgvoltg potl imgs not usd to coct ptint position immditly pio to ttmnt, but potntilly to djust th spcifiction of coct ptint position pio to th nxt ptint ttmnt. Anoth disdvntg is tht tking on o mo lctonic potl imgs dds significntly to th fction ttmnt tim. 4 Th vi of potl imgs my nd to b pfomd by dition oncoist, nd this cn dly ttmnt significntly if on is not vilbl 5. 9

214 Chpt 4: gisttion to th ttmnt isocnt 4..4 Gnty mountd in oom kilovoltg imging. Kilovoltg x-ys poduc supio img qulity, but on must hv souc of kilovoltg x-ys to cqui such imgs. Th id is not n: on of th fist thpy lin ccltos instlld t Stnfod Univsity hd dignostic souc tht could b divn in nd out of th bm 5 cm blo th mgvoltg tgt 6,7. Th id s vivd in non commcil implmnttion of kv souc mountd on th gnty of lin cclto t n ngl of 37 dgs fom th mgvoltg ttmnt hd 8. Commcil implmnttions 9,3 us gnty mountd kv soucs nd dtctos tht othogonl to th Mgvoltg bm. Th dtcto is gnlly tctbl o dtchbl, but sfty nd clnc 3 is n issu. 3D locliztion by kv imging quis tht th gnty b ottd by 9 dgs. Th is mximum spd of ottion fo th gnty of 5 sconds fo 9 dgs 3, so this involvs minimum 5 scond dly in cquiing th scond img. This dgds fficincy though th dly nd ccucy though th ptint movmnt 33. Th qulity of isocntic ottion is lso n impotnt fcto In oom Mgvoltg Con bm CT By otting th gnty hil th MV bm is on, on cn cqui id bm CT scn ith singl ottion of th gnty. This tks ith 3 sconds o full minut to cqui, dpnding on hth full o hlf ottion is utilizd. Th dvntg of this tchniqu is 3D img cquisition. Th MV imgs cn b mo usful fo imging ptints ith hip posthss. Disdvntgs th high dos to th ptint, suscptibility to motion tifct du to th long cquisition tim 33, nd th intinsiclly bd img qulity 9. Th 3D imging cn b s much cus s blssing. Contouing th tumou tks tim 4, nd my qui dition oncoist 5. This hs bn mitigtd by th us of img fusion, nd th dvnt of dptiv diothpy 35, h th 3D img is usd to slct btn numb of p ppd plns. Som of ths dcisions could b md just s sily using pln kv o MV imging In oom kv con bm CT A gnty mountd kv souc nd dtcto cn b usd to obtin kv con bm CT. Th img qulity is supio to th MV con bm CT, nd th dos is dcsd, but th poblms of cquisition tim motion tifcts 33, fficincy 5 nd intpttion min 4. Although th dos is dcsd, it is not insignificnt compd to th thpy dos; dily con bm CT imging thoughout fctiontd ttmnt, up to. Gy fom imging compd to 64 Gy fom thpy in til of img guidd diothpy 36. Th dcision s to hth to tk th imging dos into ccount s pt of th ttmnt plnning pocss 58, nd th tchnicl qustion of ho this my b chivd 37, s ll s th diobioy of imging vsus thpy dos 58, ll cunt s of invstigtion. Th limiting fcto fo gisttion ccucy fo 3D-3D mtching is th con bm CT slic thicknss 38. Fo pcticl sons, th con bm CT cn only b cquid t couch zo, so non copln bm gisttion cnnot b vifid immditly pio to ttmnt In oom dignostic CT A boutiqu solution is dignostic CT scnn mountd on ils in th ttmnt oom. Th loction of th CT gnty cnt of constuction to th isocnt is chivd to ithin n ccucy of bout 3 mm. Th most significnt poblm is th movmnt of th ptint hn bing movd btn th ttmnt position nd th 9

215 Chpt 4: gisttion to th ttmnt isocnt imging position compd to s singl isocnt systm 39. Economic limittions tht th dignostic qulity CT scnn cnnot b usd fo CT scns hil th Lin Acclto is bing usd fo ttmnt, nd vic vs In oom Ultsound Th is commcil systm (BAT, Nomos, Sickly, PA, USA) tht uss ultsound in th ttmnt oom 4. A poblm s tht th pssu of th tnsduc on th bdomn movd th postt 4,4,43. Clinicl compison suggsts postt locliztion ithin 4 mm, compd to -3 mm ith CT on ils 44. Th ultsound imgs cn b difficult to intpt coctly 45. Tns cnil ultsound in dults psnts tchnicl difficultis in dults bcus of th skull bi to sound tnsmission, but hs bn shon to hv som ppliction to Gliom tgt volum mking fo diothpy Implntd fiducils th thn gist to bony ntomy, fiducils cn b implntd in th tumou nd imgd diogphiclly 45. Th pimy dvntg is tht locliztion is dict to tumou, lthough hth this cn b compomisd by migting fiducils 47 is disputd 48. Th pimy disdvntg is tht th pocdu is invsiv. Implntd fiducils not suitbl fo ll ptints. Th fiducils must b imgd, nd th is som unctinty ov th bst y to ccomplish this Implntbl dio tnsponds A systm of implntd dio-tnsponding fiducils (Clypso, Clypso Mdicl Tchnois, Sttl, WA, USA) is commcilly vilbl. Th ccucy chivd in phntom msumnts is sub millimt 49, nd th dvics cn b implntd dictly ithin th tumou. Sinc th is no dioicl budn to dtmining th position of th mks, thy idlly suitd to continuous l tim tcking. 5 Th disdvntg is tht th dvics hv to implntd, hich is invsiv. It is contndd tht th tnsponds do not migt Msuing to ptint sufc. Stndd diothpy fquntly uss singl point pob of distnc, ith ith physicl o n opticl chck. Th us of bckpoints, nd pin nd c tchniqus in th ly dys of diothpy ith non isocntic mchins libl, pcticl solutions to th poblm of ptint positioning. Th dionics dpth hlmt usd in stotctic diosugy to chck th plcmnt of nuosugicl fm to th skull is th ultimt us of physicl pob to chck position 5. A commcilly vilbl 3D sufc img gisttion systm (Align T, Vision T, London, UK) uss stoscopic cms nd sophistictd sufc mtching lgoithms to position th ptint ith stndd dvition of.75 mm 53. Th dvntgs th pcticlity, nd tht ths tchniqus not invsiv. Th disdvntgs th tim tkn, nd tht th gisttion is dtmind fom th ptint skin sufc. If th tgt is loctd ithin th ptint, ny intnl motion ltiv to th ptint skin cnnot b ccountd fo. 93

216 Chpt 4: gisttion to th ttmnt isocnt 4.. Ptint Fixtion Bit blocks, vcuum bgs nd oth mthods of ptint fixtion cn b usd to hlp th ptint tin position fo ttmnt ft th initil positioning is chivd. Som fixtion is lso usd to stblish th ptint position. Th lst sophistictd ppoch is n lignmnt mk on th fixtion to indict th isocnt if th ptint is positiond coctly ithin th ptint fixtion dvic. Th ultimt sophistiction of this tchniqu is th nuosugicl fm, hich is kpt in plc fom imging to ttmnt to stblish ptint positioning to th isocnt to sufficint ccucy fo stotctic ttmnt to b chivd. Th disdvntg is th invsivnss. Th ptint hd lso movs ithin th fm hn th ptint lis don. It is ncssy to nsthtiz young childn ho qui this locliztion otting th ptint out of th hoizontl pln. All of th pvious mthods hv limittions compnsting fo ptint ottion. Although th ptint suppot systm nbls ottion of th ptint in th hoizontl pln, ottion out of th pln idlly quis tiltbl couch, hich is no commcilly vilbl (Hxpod 54, Mdicl Intllignc, Schbmünchn, Gmny). Th is contovsy ov th y to chiv optiml lignmnt ith pln imging in th bsnc of cpcity to ott th ptint in th dimnsions 89,9,9. Coct ointtion of th ptint to th lvl of ccucy quid fo pln img mtching is not quid fo diothpy ttmnt p s. Angls of lss thn.5 dgs ccptbl in stndd pctic Summy of ptint positioning. A id vity of mthods hv bn usd to position ptints in diothpy, but ll of thm suff fom limittions. Not ll of thm stblish gisttion to th 3D ttmnt plnning CT scn. Som of thm only pcticl to us fo offlin vi, o qui gisttion btn kv nd Mgvoltg imging. Som invsiv, nd som lt only to th ptint sufc. An idl ptint positioning systm must b fficint, ccut nd conomic. On systm tht povids ths th fundmntl dvntgs ithout ny of th bov limittions is th BinLb ExcTc systm, hich is th subjct of th nxt sction. 4.3 IGS (ExcTc, BinLb AG, Fldkichn, Gmny). Th IGS is n fficint, ccut nd conomic systm fo positioning th ptint ithin th diothpy ttmnt oom to position dtmind by CT imging pfomd motly fom th ttmnt oom. This 3D imging could b CT scn fom CT PET scnn, so th poblm of cogisting functionl imging to th ttmnt isocnt in th ttmnt oom cn b solvd by th IGS. Th nvisiond co-gisttion chin fo functionl imging to th ttmnt isocnt is: fom th PET scn to th intinsiclly gistd CT scn of th PET-CT; Ds clcultd fom th CT thn gistd to pln imgs in th ttmnt oom to chiv gisttion of th skull. Fo th intcnil lsions considd, gisttion of th skull mounts to gisttion of th tumou. Th IGS uss kv imging in th ttmnt oom, but it is not gnty mountd. Instd, to x-y tubs, tht cssd into th floo of th ttmnt oom, point t to kv digitl dtcto pnls mountd on th ciling. Th IGS is modul, nd cn b put to mny uss fo diffnt clinicl sits, nging fom fmlss intcnil stotctic ttmnts to postt 94

217 Chpt 4: gisttion to th ttmnt isocnt ttmnts using implntd fiducils. Compd to in oom con bm CT, th IGS offs fst img cquisition nd pocssing, lo dos, supio sptil ccucy, nd th bility to img immditly bfo ttmnt t ny couch ngl. Con bm CT povids 3D imging, hich th IGS cnnot. This cn b mitigtd by th us of implntd fiducils, but tht is topic outsid th scop of this thsis. Th dsciption givn h fo componnts nd pocdu lts to th IGS s implmntd fo fmlss int cnil stotctic ttmnts, hich is th ppliction ith th most stingnt sptil ccucy quimnt. Th dtmintion of th sptil ccucy of this systm in clinicl pctic is th mjo thm of this chpt IGS componnts. Th IGS consists of hd nd soft dployd t th CT scnn nd t th ttmnt unit. At th CT scnn, ll of th dditionl IGS quipmnt is dmountbl. A cbon fib bs (mkd by n A in Figu 4.3.-) locts on top of th flt CT couch. Th bs dpts thin, lightight mount (mkd by C in Figu 4.3.-) fo msk bsd individul ptint hd immobiliz. A tgt positionl locliz (TAPO-mkd by D in Figu 4.3.-) is mountd to th bs, ov th ptint hd, duing CT imging nd cis fiducils tht povid stotctic locliztion to th CT dt st. At th ttmnt oom, th IGS is pmnnt instlltion, consisting of th floo cssd x-y units (mkd by to Cs in Figu 4.3.-), th oof mountd cms (Mkd by to As in Figu 4.3.-), n infd pojction nd dtction systm mountd on th oof btn th to kv x-y flt pnl dtctos (Mkd by B in Figu 4.3.-), nd tiltbl couch top, tmd th obotic couch mountd pmnntly in plc of th stndd couch top (mkd by D in Figu 4.3.-). Th couch top dpts pojcting ttchmnt (Mkd by n F in Figu 4.3.-) tht holds thin lightight mount fo msk bsd immoblis idnticl to tht mountd on th CT couch. This ttchmnt cn lso dpt th TAPO o n y of six inf d flctiv sphs ov th top of th ptint hd. Th contol oom of th ttmnt unit hs n xt kybod nd scn fo th IGS soft (mkd s A in Figu ), s ll s joint kilovoltg x-y contol unit (mkd s B in Figu ). Th soft is lso ccssibl in th ttmnt oom fo p-positioning contol puposs though touch scn. A kv gnto unit (mkd s A in Figu ) nd th pimy IGS comput systm (mkd s B in Figu ) lso loctd in th ttmnt oom bhind th ttmnt unit. 95

218 Chpt 4: gisttion to th ttmnt isocnt Fig Th IGS ttmnt oom nd CT quipmnt plcd sid by sid. Sinc th CT quipmnt is ntily dmountbl, it is possibl to tnspot it to th ttmnt oom nd sho th to systms sid by sid. Th CT quipmnt includs dmountbl cbon fib bsbod (A) hich is lignd to th CT couch top by to univsl loctos (B). Th bsbod suppots msk hold xtnsion (C) tht is idnticl to tht on th lin cclto. Th TAPO (D) mounts to th msk hold xtnsion nd cis th fiducils tht povid th 3D stotctic locliztion function of th CT Th systm on th lin cclto cn mount n y of opticl mk sphs (E). Sinc th gomty of th TAPO nd th y knon, th stotctic coodints of th ttmnt tgt, dtmind by fnc to th fiducils visibl on th CT scn, cn lso b usd in th ttmnt to plc tht tgt t th linc ttmnt isocnt by moving th bd until th y is in th quid position. In clinicl pctic th ptints hd is ly in th sm position ltiv to th msk xtnsion t ttmnt nd imging, so this p-positioning lmost lys (99.5% of th tim und WBC stndd ttmnt pss conditions s tbl 4..-) quis coction. Fig Th IGS quipmnt in th lin cclto ttmnt unit oom. A- oof mountd kv dtcto pnls, B- oof mountd opticl dtction systm. C- Floo cssd kv x-y tubs D- IGS obotic Couch top poviding pitch nd oll djustmnt of th couch top. E- obotic couch blu tooth communiction modul. F- Msk hold xtnsion. 96

219 Chpt 4: gisttion to th ttmnt isocnt Fig Linc contol oom IGS hd. Th contol oom contins n xt comput scn (A) nd kybod fo th IGS soft. Th scn is shon h in p-positioning mod, ith Antio- Postio nd Ltl Digitlly constuctd diogphs clcultd fom th stotctic plnning CT scn shoing th xpctd position of th ptint bsd on th position of th opticl mk sph y. A joint kilovoltg x-y contol unit (B) is usd to st x-y tub sttings (kv, ma) nd initit kv xposus. Fig IGS ttmnt oom uxiliy instlltions. Th ttmnt oom lso contins th shd gnto unit fo th to kv x-y tubs (A) nd th cntl contol comput fo th IGS (B). Ths instlltions povid kv po nd computing po/stog. Dict us intction ith ths units is limitd IGS x-y sub systm Th IGS x-y sub systm is md up of pi of kv x-y tubs mountd cssd into th floo, ch imd t oof mountd dtcto, pod by shd gnto nd contolld by mnul contol unit linkd to th IGS soft. On of th kv x-y tubs (Vin -: Vin Mdicl Systms, Plo Alto, CA USA) cn b sn in its floo css ith th cov movd in Figu A clos up of on of th oof mountd kv x-y dtctos is sn in Figu Th dtctos hv pixl siz of.4 mm ith snsitiv of.5 x.5 cm (modl XD 5-4 AL:Pkin Elm, Wlthm, MA). 55 Th dtcto citicl fquncy, f 5, (th point t hich th spons fquncy is 5% of th mximum ltiv modultion tnsf function) is.7-.9 lin pis p mm. 55 Th fild of vi of th dtctos is 3 mm by 3 mm t th isocnt, th nominl pixl siz is.54 mm by.54 mm t isocnt (s Figus nd ). Th uniqu chctistic of th IGS x-y sub systm is its us of non othogonl pid kv img cquisition t ltivly lg souc isocnt (.4 m) nd souc-dtcto distncs (3.6 m). 55 Th systm hs th dvntg of igidity compd to gnty mountd systms, but th systm is 97

220 Chpt 4: gisttion to th ttmnt isocnt gistd to th isocnt by fqunt (dily o kly) to stp dily clibtion pocss. 55,56 (S Figus , , nd ). Th systm llos vibl sttings of kv nd ma nd ms, but in pctic fo intcnil ok it is gnlly sufficint to us fo th mjoity of ptints xposu sttings of 8 kvp, 6 ma, 8 ms,.8 mas, ith occsionl us of hd hd stting of kvp, ma, 3 ms, 3. mas nd th dos quid to obtin on cnil img s found t WBC to b. mgy 57, hich is in gmnt ith publishd msumnts 58. Fig On of th floo css mountd kv x-y tubs of th IGS, shon ith th floo cov movd. Th mnully djustbl collimto housing (Lin MC-5-C) collimto housing is st to squ fild siz of ppoximtly.5 cm t 8 cm FID, hich cosponds to 5.5 cm t isocnt, givn souc to isocnt distnc of.4 m. Th x-y tub hs mximum kvp of. Fig On of th oof mountd kv x-y img systms in clos up. Th dtcto hs pixl siz of.4 mm ith snsitiv of.5 x.5 cm (modl XD 5-4 AL:Pkin Elm, Wlthm, MA). Fig Img of cm dio-opqu ul insid th IGS soft. Th objct bing imgd s st up t th isocnt ppndicul to th kv bm xis. Dspit th utmost c in th st up, th objct s still imgd ith smll ngl. This indicts tht th on scn disply is th dt, bfo th gomty is coctd by tnsfomtion divd fom th clibtion of th kv systm. Th blu coss in th cnt of th img indicts th position of th isocnt divd fom th clibtion. Not lso tht th soft is qusting noth img to b tkn. If th is not sufficint ttnution in th 98

221 Chpt 4: gisttion to th ttmnt isocnt cquid kv img th systm ill not pocd to gisttion. This fustts ttmpts to do phntom xpimnts ith simpl bll bing phntoms in i. Fig High Dos t (HD) chck position souc ul tht s imgd in Figu Dspit mticulous stup of th phntom, th img still hd visibl ngl, lding to th conclusion tht th physicl lignmnt of th x- y dtctos is only ppoximt; fctos dtmind though clibtion usd to coct th img gomty to obtin infomtion gistd to th isocnt IGS Opticl sub systm Th pupos of th IGS opticl sub systm is to ccutly dtmin th ltiv position of th ptint fom th position of th opticl mk sphs. Th IGS opticl sub systm is quid bcus th point t hich th couch pivots is mot fom th isocnt, to th xtnt tht it is impcticl to dtmin th position of th ptint to th lvl of ccucy quid fo stotctic ttmnt fom th physicl ngl of th IGS obotic couch. Th IGS opticl sub systm is md up of oof mountd inf d pojction nd dtction systm. Th systm lis on stoscopic dtction of infd (I) flctiv mk sphs. Th IGS opticl sub systm is dscibd by Wgn t l 59. It includs stoscopic infd cms on singl oof mountd ssmbly (s Figu ). Th opticl systm povids l tim tcking of sphicl I flctos t fquncy of ppoximtly tims p scond. Th clibtion of th opticl systm is chivd ltiv to th ttmnt oom isocnt lss using phntom (s Figu nd ). Onc th opticl systm is clibtd it is usd in tun to position kv imging phntom t th isocnt to clibt th IGS kv imging sub systm. Adjusting th pitch of th couch s pt of th clinicl pocdu quis th couch to tilt bout point bout.7 mts fom th isocnt. Although th ngul dout is ccut to. dgs, t this distnc pitch of. dg ill chng th hight of th ptint ltiv to th isocnt by bout 3 mm. Achiving stotctic ccucy by stting th couch pitch ngl ould thus b xtmly chllnging nd xpnsiv to chiv, if it could b don t ll. Th opticl tcking systm llos ltiv movmnts nd ottions of th ptint to b chivd to sufficint ccucy to llo th kv imging systm to dliv finl confimtion of ptint positioning to ithin th ccucy quid fo stotctic ttmnts. Fig IGS opticl sub systm oof mountd infd pojction/dtction systm. Th infd light is sn in this img s to blu ings composd of smll disct blu dots. Th inf d light is visibl to th digitl cm usd to obtin this img, but is not nomlly visibl to th nkd y. 99

222 Chpt 4: gisttion to th ttmnt isocnt Fig Th IGS opticl sub systm clibtion phntom. It is ssntilly tblt tht hs th othogonl lins tht mtchd by y to th ttmnt lss tht indict th isocnt. Th fiv flctiv mk sphs on top of th tblt thn loclizd by th opticl tcking sub systm, nd this infomtion, togth ith th knon gomty of th tblt, is usd to clibt th opticl tcking sub systm to th lin cclto ttmnt isocnt. Th mk sph y is symmtic, nd th tblt must b positiond in th ointtion shon on th upp sufc of th tblt to coctly clibt th ointtion of th opticl systm to th linc coodint systm. Fig Th IGS opticl sub systm clibtion phntom, shon lignd to th ttmnt oom lss tht indict th isocnt. Fig Clibtion of th IGS x-y sub systm. Onc th IGS opticl sub systm hs bn clibtd, it is usd in tun to position kv imging phntom t th isocnt of th lin cclto. This phntom contins fiducils tht imgd in tun by th kv units, to clibt th IGS kv sub systm to th isocnt. Th o mkd C indicts th instion point fo fiducil. Th o mkd B indicts on of fou I flctiv cicul sufcs tht nbl th I sub systm to position th phntom ccutly. Th o mkd A shos th light fild fo ptint spcific mini-multilf collimto fild. Th light fild hs bn tund on ith th gnty t zo dgs (bming vticlly donds) to povid n ointtion of th img.

223 Chpt 4: gisttion to th ttmnt isocnt IGS clinicl pocdu A bochuil dsciption of th IGS fmlss intcnil stotctic clinicl ttmnt pocdu cn b found in th littu. 6 Th lvnt pts of th IGS clinicl ttmnt pocdu fo fmlss intcnil stotctic ttmnt fo th puposs of this ok bst xplind by folloing th hiddn tgt tst ith n ANTHOP hd phntom. Th hiddn tgt tst ttmpts to tst th full imging nd ttmnt pocss ith phntom ith n mbddd fiducil. Figus to illustt th pocdu. Th finl stp of th hiddn tgt tst is Winston Lutz tst 6 of th position of th hiddn tgt, but th finl stg fo ptint is fo th ttmnt bms t tht couch ngl to b givn. Th clinicl dcision pocss is shon in Figu Th clinicl pocdu povids fou nvloping lys of ptint positioning ccucy: Ly Initil Linc ptint p positioning t couch zo. (s Figu ) Ly TAPO chck. (s Figu ) Ly 3 kv imgs nd uto fusion (s Figu ) Ly 4 vi of img fusion. (s Figu ) Th nvloping lys of ccucy povid potction fom dvs clinicl sults tht might b cusd by th filu of singl componnt of th pocdu. Fo th pupos of this sch ok it is impotnt to not tht in th stndd clinicl pocdu t WBC, hn th couch is ottd to n ngl, if th position is found to b out of opticl tolnc, this is coctd by unlocking th bd nd mnully djusting its position in th longitudinl nd ltl dictions to chiv opticl tolnc t th n couch ngl. (Th systm displys th dvition fom isocnt dtctd by th opticl systm on comput scn in th ttmnt oom; th opto cn vi this in l tim s thy mnully djust th bd.) It is tht th motoizd vticl motion of th bd is quid to gin position ithin opticl tolnc. In Figu , this is summizd simply s ott ttmnt couch to nxt ngl und I guidnc. Fig Stp of th hiddn tgt tst. Th ANTHOP hd phntom ith n instd bll bing is plcd on th CT scnn in custom md msk. Th msk mounts to th msk hold to position th phntom igidly. Th msk hold is mountd on cbon fib bs tht is loctd on th ttmnt couch by univsl loctos, on of hich cn just b sn in position t th top of th CT couch. (s Figu fo n xplntion of th IGS CT quipmnt.)

224 Chpt 4: gisttion to th ttmnt isocnt Fig Stg of th hiddn tgt tst. Th TAPO is ttchd nd stotctic CT dt st is cquid. Fig A clos up of th TAPO, shoing th V pttn fiducils usd to stblish th stotctic coodints. Fig Stg 3 of th hiddn tgt tst, th CT scn is impotd into th IGS TPS nd th stotctic fiducils (th six hit dots in th img) uto-dtctd.

225 Chpt 4: gisttion to th ttmnt isocnt Fig Stg 4 of th hiddn tgt tst, Th isocnt is plcd on th fiducil imgd in th stotctic CT scn, fom hich th IGS TPS is bl to dtmin th stotctic coodints, sn on th bottom ight of th scn. Fo ptint, th isocnt ould b plcd insid mkd tumou volum. Fig Stg 5 of th hiddn tgt tst, xpot of dt to th IGS. Th CT dt st nd th isocnt coodints xpotd fom th IGS TPS to th IGS. This concluds th plnning pt of th clinicl pocss. Fig Stg 6 of th hiddn tgt tst. In th ttmnt oom, th ptint/phntom is ppositiond to isocnt und opticl guidnc. Th initil positioning is pu tnsltion ith lvl couch. If th phntom/ptint is positiond in n idnticl position in th msk t imging nd ttmnt, th isocnt is no in th coct position. In pctic this dos not hppn, but this supplis th fist of fou lys of positioning. 3

226 Chpt 4: gisttion to th ttmnt isocnt Fig Stg 7 of th hiddn tgt tst. Whil th couch is lvl, th TAPO is dptd to th ttmnt couch (th TAPO dpts to both th ttmnt nd imging couch). IGS TPS isocnt nd fild outlins cn b ovlid to chck ginst lss nd light bm. This supplis scond ly of positioning. Fig Stg 8 of th hiddn tgt tst. Pid kv imgs cquid nd fusd ith digitlly constuctd diogphs (Ds) clcultd fom th CT scn ithin th IGS soft. If th coction quid is ithin tolnc, this supplis th thid ly of positioning. If th coction is outsid tolnc fo position o ottion, coction is md to ngl nd position. Opto vi of th img fusion is th fouth ly of positioning. Fig Fmlss stotctic ttmnt dcision pth. 4

227 Chpt 4: gisttion to th ttmnt isocnt IGS scintific pots A sch of th littu givs ov 45 fncs tht dl ith th IGS. Th IGS cn b usd fo mny diffnt clinicl sits, fo xmpl ttmnt of liv mtstss 6, spinl tumous 63, postt cnc 64, nd gtd ttmnt of lung cnc 65, but th pimy intst in this ok is in intcnil ttmnts. Extcnil ttmnts involv dditionl ptint positioning considtions, not dlt ith in this thsis, tht duc th chivbl sptil ccucy. This thsis concntts on intcnil ttmnts bcus thy hv th most dmnding clinicl quimnt fo mximl sptil ccucy. Th clinicl sptil ccucy of th IGS is thus most impotnt hn it is usd fo intcnil ttmnts. Th IGS hs volvd ov tim, bginning s simply n opticl systm 66, nd volving to includ pln kv imging. Although th motivtion to intoduc th kv systm is not ll documntd in th littu, Vlln 67 cdits Mitsubishi Elctonics Co. in collbotion ith th Hokkido Univsity ith pioning th oom mountd kv imging ppoch 68,69, follod by UZ Bussl in collbotion ith th IGS vndo to poduc n ly vsion of th IGS ith kv x-y concpt 7, ith oof mountd x-y tubs nd singl couch mountd kv imging dvic. Th focus in this ok is on th contmpoy vsion of th IGS, ith pid floo cssd x-y tubs nd oof mountd kv dtctos. pots in th littu on th quivlnc of clinicl sults btn fm bsd intcnil stotctic ttmnts nd fmlss intcnil stotctic ttmnts ith th IGS 7, hil of gt comfot to clinicl pctitions, not pticully usful in dtmining hth th systm ill b dqut fo gisttion of functionl imging to th ttmnt isocnt, nd so only of pssing intst to this ok. Similly th ng of studis tht us th IGS to t th ffctivnss of vious ptint immobiliztion sttgis, 7,93 but th focus in this ok is on th ccucy tht th IGS itslf cn chiv in clinicl pctic, not th us of th IGS to t oth systms tht infio to th IGS. Sophistictd xpimntl studis tht stblish th dosimtic consquncs of mislignmnt in vious pcticl ST plnning scnios 73, 74 vitl indictos of th quimnt of sptil ccucy fo gnl stotctic pctic, but piphl to th point of intst in this ok. Th mny pots in th littu of phntom bsd msumnts of th ccucy of th IGS fmlss intcnil stotctic systm. 75,76,77,78 Although msuing th ccucy ith hich phntom hs bn plcd to th od of mm is chllng fo most mdicl physics dptmnts, som of th phntom msumnts sufficintly ccut to b bl to discimint btn th sults obtind ith sgmntd nd igid phntoms. 7 Th justifiction fo xtnding ths findings to clinicl pctic is gnlly on of ncssity. Clinicl vifictions of th ccucy of th IGS fmlss intcnil stotctic systm f nd mo vid. On mthod is to chck IGS positioning ith Con Bm CT; Wlls t l. 79 found gmnt ithin. mm. M t l. 8 usd ssntilly th sm mthod nd plcd limit of.5 mm fo phntoms, nd.5 mm fo ptints, on th clinicl ccucy of th IGS fo intcnil fmlss stotxy. Jin t l 88 ingniously mskd diffnt s of th kv x- y imgs s mthod of dtmining th ccucy of th 6D fusion lgoithm. Vbkl t l 8 usd pt IGS kv imgs duing ttmnt to ssss ptint motion. Th IGS implmnts tnsltion in nd ottion bout ll th xs. Most oth pln ptint lignmnt systms implmnt only tnsltions. Th hs bn thoticl discussion in th littu bout hth coction by tnsltion lon is dqut 89,9,9. Th xpcttion is tht tnsltion is sufficint fo implntd fiducils, but suscptibl to o hn bony ntomy mot fom th tumou is usd fo locliztion. This is xctly th clinicl 5

228 Chpt 4: gisttion to th ttmnt isocnt scnio fo cntl intcnil lsions loclizd using pln kv imgs of th skull. Msumnts ith th IGS shod tht coction by combind ottion nd tnsltion povidd supio locliztion to coction by tnsltion lon. 83 It hs bn dtmind tht th slic thicknss of th stotctic CT scn hs stong influnc on th ccucy of pln diogphic ptint positioning fo diosugy. 8 Msumnts ith th IGS hv lso dmonsttd th dpndncy of ccucy on CT slic thicknss Phntoms vs Ptints: Hypothss Bfo stting th hypothss it is usful to summiz th contxt in hich th hypothss is. Th nd fo functionl imging gisttion to th ttmnt oom isocnt hs bn stblishd. Th quimnts fo such gisttion hv bn outlind (sction 4.); cost, ccucy, fficincy. Cuntly vilbl mthods fo positioning th ptint hv bn vid (sction 4.), nd it hs bn shon tht th IGS my b suitbl systm fo chiving gisttion of functionl imging in th ttmnt oom (sction 4.3). IGS clinicl pocdu hs bn dscibd nd th littu poting it hs bn vid (sction 4.3.5). Wht mins is th qustion of hth th IGS ill b sufficintly ccut in clinicl pctic. Th IGS output ill lys vntully pot tht th ptint is coctly positiond ithin th spcifid tolnc, nd phntom msumnts suppot this, but phntom msumnts not xctly th sm s ptint ttmnts. A pimy mining concn is ho clinicl diothpy dptmnt might vify th clinicl ccucy of n IGS. Publishd studis fom oth goups of som utility, but not in thmslvs sufficint. To b vlid, such dtmintion must b spcific to th pocdus nd tchniqus usd in th dptmnt, nd fo th ptints ttd in tht dptmnt. A ltd concn is hth th pocdus usd by th dptmnt stisfctoy, o if thy should b modifid. An ns to this qustion should b povidd by vifiction of th clinicl ccucy of th IGS spcific to th dptmnt s tchniqus nd ptints. In th mind of this chpt tn ltd hypothss ith spct to th ccucy of IGS in clinicl pctic fo fmlss intcnil SS nd ST ill b tstd. Th fist hypothsis is tht th IGS cn b usd in clinicl pctic ith sufficint sptil ccucy fo fmlss intcnil stotctic diosugy (SS) nd fmlss intcnil stotctic diothpy (ST). Th quid ccucy is to som xtnt dpndnt on vilbl tchnoy, nd climd ccucy cn vy fom dptmnt to dptmnt, but in gnl it is usul to f to th AAPM guidlins 84 fo spcifiction of th sptil ccucy quid fo stotctic ttmnt. Th scond hypothsis is tht th clinicl ccucy of th IGS cn b dtmind fom vi of sults obtind fom th IGS itslf in stndd clinicl pctic. Th thid hypothsis is tht th ill b spcts of th clinicl ccucy of th IGS tht cn b dtmind fom vi of IGS ttmnt dt tht cnnot b dmonsttd by phntom xpimnts. Th fouth hypothsis is tht vi of th sults obtind ith th IGS in clinicl pctic cn b usd to guid chngs in ttmnt tchniqu, if quid, to impov ccucy. Th fifth hypothsis is tht vi of th sults obtind ith th IGS in clinicl pctic cn sho tht tightning th pss citi povids diminishing tuns in tms of clinicl ccucy. Th sixth hypothsis is tht th lg th distnc tnsltd by th lst coction, th lss ccut th ptint positioning ith th IGS ill b in clinicl pctic. 6

229 Chpt 4: gisttion to th ttmnt isocnt Th svnth hypothsis is tht th ccucy of th IGS positioning in clinicl pctic ill b dpndnt on th numb of ittiv 6D coctions it took to chiv tht positioning. Th ighth hypothsis is tht th ccucy of positioning ith th IGS in clinicl pctic ill impov ft th fist to fctions of stotctic diothpy (ST). Th ninth hypothsis is tht th ngl coctions dtmind by th IGS cn b dtmind to b coct by viing th sults obtind ith th IGS in stndd clinicl pctic. Th tnth nd finl hypothsis is tht it ill b possibl to stimt th influnc of tifcts of th mthod usd to dtmin th clinicl ccucy of th IGS, pdoxiclly gin by viing th IGS sults fom stndd clinicl us of th IGS. Th fist stp in th invstigtion nd nlysis is to fomlly dfin coodint systm. 4.5 Coodint systms dfinition. Th IGS pots tnsltions nd ottions s thy pply to ptint in th hd fist supin (HFS, ptint sting on thi bck, ith thi fc to th ciling, hd clos thn ft to th ttmnt unit) ointtion on th ttmnt couch. Sinc this coodint systm is ltiv to th ptint, it otts hn th ttmnt couch is ottd. Th to icl choics fo th lignmnt of fixd coodint systm in hich to intpt ths sults, lignmnt to th xis of ottion of th couch, nd lignmnt to th pln contining th xs of th non othogonl kv imging bms. This givs th spt coodint systms, nd it is ncssy to dscib thm fully bfo pocding to us thm fo nlysis igid l old coodint systm. It is ncssy to dfin th folloing ight hndd th dimnsionl ctilin coodint systm tht is indpndnt of couch ottion nd lignd to th xis of ottion of th ttmnt couch. i f is unit vcto in th x_zo xis, th supio (SUP) diction (ith th ptint in th hd fist supin ointtion) zo t isocnt, positiv tods th gnty. j f is unit vcto in th y_zo xis, th ptint IGHT diction (ith th ptint in th hd fist supin ointtion) zo t isocnt, positiv y fom th mz ntnc. k f is unit vcto in th z_zo xis, ptint ntio (ANT) diction (ith th ptint in th hd fist supin ointtion) zo t isocnt, positiv vticlly bov th isocnt. W cll this coodint systm th l old coodint systm, s illusttd in Figu

230 Chpt 4: gisttion to th ttmnt isocnt Fig Th l old coodint systm. Th d o mkd x indicts th x_zo xis. i f is unit vcto in th fixd x_zo xis, th SUP diction (ith th ptint in th hd fist supin ointtion) positiv tods th gnty. Th gn o mkd y indicts th y_zo xis. j f is unit vcto in th fixd y_zo xis, th ptint IGHT diction. Th blu o mkd z indicts th z_zo xis. k f is unit vcto in th fixd z_zo xis, th ptint ANT diction. Th oigin is t th isocnt. To lins of sting hv bn un to indict th kv bm xs, ths un fom th kv x-y soucs in th floo (on visibl, on off scn blo scn ight), to th kv x-y cms on th oof (on visibl, on off scn bov scn). Th to lins of sting sn to intsct t th isocnt otting couch bsd coodint systm. It is ncssy to dfin ight hndd th dimnsionl ctilin coodint systm dpndnt on couch ottion. i θ, o simply i h th couch ngl is not quid, is unit vcto in th couch longitudinl xis, zo t isocnt, positiv byond th isocnt y fom couch suppot. j θ, o simply j h th couch ngl is not quid, is unit vcto in th couch ltl xis, zo t isocnt, positiv byond th isocnt tods th ptint ight in HFS ointtion. k θ, o simply k h th couch ngl is not quid, is unit vcto in th vticl diction, zo t isocnt, positiv vticlly bov th isocnt. W cll this coodint systm th couch bsd coodint systm ltionship btn l old nd couch bsd coodint systm. W cn stngthn ou dfinition of th l old nd couch bsd coodint systms by dtmining th tnsfomtions tht mp btn th to coodint systms. Sinc th couch bsd systm otts ith th ttmnt couch, nd th l old coodint systm dos not, tnsfomtions tht mp btn th to systms dpnd on th couch ottion ngl, θ. At th WBC, θ is zo hn th long xis of th couch is lignd to th xis of ottion of th ttmnt gnty. Th couch ottion ngl incss hn th couch is ottd tods th ptint s ight in th HFS ointtion. 8

231 Chpt 4: gisttion to th ttmnt isocnt Th tnsfomtion fom th l old coodint systm to th couch bsd coodint systm is givn by qution iθ cosθ sinθ i f j θ sinθ cosθ j f Eqution k θ k f Th vs tnsfomtion fom th couch bsd coodint systm to th l old coodint systm is givn by qution i f cosθ sinθ iθ j f sinθ cosθ jθ Eqution k k f θ l old coodint systm spcifiction of kv bm ointtions. To dfin igid coodint systm lignd to th pln contining th to kv img bms, nd its ltionship to th l old coodint systm, th diction of th kv bms must b dfind in th l old coodint systm. Instlltions of th IGS vy fom cnt to cnt, nd th hv bn dsign ittions in th stup of th kv x-y bm gomty. Wht is dscibd h is th gomty of th kv bms s instlld t WBC. Th kv x-y tubs loctd in th floo t n ngl of 45 dgs ith sid of th gnty. On n ovhd vi, s instlld, th lins fom th kv soucs to th kv imgs thus mk n ngl of 9 dgs ith ch oth vid fom bov th isocnt, s shon in Figu Fig Th lins fom th kv soucs to th kv imgs mk n ngl of 9 dgs ith ch oth vid fom bov th isocnt. Th sting lins visibl in th img mk th kv bm xs. Th img is tkn fom bov th isocnt. Th ngl mkings on th tuntbl thus function s potcto. Th cms mountd in th oof such tht th lins fom th kv soucs to th kv imgs mk mximum ngl of 45 dgs ith th hoizontl pln. Both lins pss though th isocnt. Fom th bov configution it cn b dtmind tht th to unit vctos plll to th lins fom th kv soucs to th kv imgs ˆ i f j f k f Eqution

232 Chpt 4: gisttion to th ttmnt isocnt b ˆ i f j f k f Eqution This implis tht th ngl α btn th to bms is 6 dgs, s ˆ ˆ cosα b i f j f k f i f j f k f Eqution And this cn b obsvd in pctic s shon in Figu Fig Th to kv bms not othogonl, but mk n ngl of 6 dgs. This iss fom simpl gomty but is h dmonsttd visully. As in th pvious figus, sting lins indict th kv bm lins. A lg, cudly fshiond potcto is hld in th pln of th kv bm xs to sho tht th bm xs mk n ngl of 6 dgs in th pln. Thus, th kv bms non-othogonl, hich hs implictions fo th ccucy of locliztion chivd ith th systm. So th to kv bms not othogonl. Th ccucy of th locliztion povidd by non othogonl bms in pticul xis is not isotopic but dpnds upon th ointtion of th vcto ltiv to th bms. To dscib this xpcttion poply quis th dfinition of igid coodint systm lignd to th gomty of th kv imging systm, hich pocd to dfin in th nxt sction Dfinition of igid coodint systm lignd to th kv bm gomty. Fom th ointtion of th kv bms dfind in th pvious sction, cn pocd to dfin igid coodint systm lignd to th gomty of th kv imging systm. A vcto ppndicul to both kv bm xs is givn by qution N ˆ bˆ i f k f Eqution A unit vcto ppndicul to both kv bm xs is givn by qution N ˆ N i f k f Eqution N 3 3 A unit vcto tht biscts th ngl btn th to kv bm xs is givn by qution ˆ bˆ i f k f 3 3 B ˆ Eqution ˆ bˆ

233 Chpt 4: gisttion to th ttmnt isocnt Sinc th biscto is copln ith â nd bˆ, thid unit vcto ppndicul to both Nˆ nd Bˆ is givn by f j B N L ˆ ˆ ˆ Eqution Th th unit vctos Nˆ, Bˆ nd Lˆ fom ight hndd coodint systm lignd to th kv bm gomty. As th kv bms not othogonl, it is xpctd tht th isocnt ill b btt loclisd in th Lˆ xis thn th Bˆ xis, du to th foshotning of ny locliztion o in th Bˆ xis. Loclistion ccucy in th Nˆ xis is xpctd to b intmdit. This tnd should mg ov lg nough smpl. A compting ffct is xpctd du to th non-isotopic sptil solution of th 3D CT scn usd to constuct th Ds to hich th kv imgs fusd. Th sptil solution of th CT scn is os (.5 mm) in th f i xis compd to th f j nd th f k xis (Both.9375 mm) hn th couch ngl is zo. Th igid coodint systm lignd to th kv bm systm cn b xpssd in tms of th coodint systm dpndnt on th couch ottion systm s follos in qutions , , nd sin 3 cos 3 ˆ θ θ θ θ θ k j i N Eqution sin 3 cos 3 ˆ θ θ θ θ θ k j i B Eqution θ θ θ θ cos sin ˆ j i L Eqution So th convsion fom th igid coodint systm, f i, f j, f k to th igid coodint systm n,b,l, is givn by f f f k j i l b n Eqution Th vs tnsfomtion, fom th igid coodint systm n,b,l to th igid coodint systm f i, f j, f k is givn by l b n k j i f f f Eqution Th ltiv ointtion of th to igid coodint systms nd th kv bms is shon in Figu

234 Chpt 4: gisttion to th ttmnt isocnt Fig Th lin cclto usd fo stotctic ttmnts shoing th ointtion of th fixd coodint systms nd th kv bm xs. Lins of sting hv bn tid fom th kv soucs to th imgs s visul cu to indict th kv img pln Soft output. Th IGS dfins th coodints in tms of HFS ptint, nd it is ncssy to dfin ho this output mps to th coodint systms stblishd. Aft n utomtic img fusion, th IGS pots commndd igid body tnsltion, fd to s 6D coction tht involvs six pmts, th tnsltions nd th ottions. Thy listd nd dfind in tun blo:. A Vticl (VET) tnsltion: th positiv diction is ANT, sm s k θ. A Longitudinl (LONG) tnsltion: th positiv diction is SUP, sm s i θ 3. A Ltl (LAT) tnsltion: th positiv diction is ptint lft, opposit of j θ 4. A ottion bout th Ltl xis: positiv ottion is fo th ft to mov don nd th hd to is. It is tmd pitch by th IGS documnttion. 85 Th quivlnt is to ott ound j θ in th opposit diction. 5. A ottion bout th longitudinl xis: positiv ottion is fo th ptint lft to mov don nd th ptint ight to mov up. It is tmd oll by th IGS documnttion. 85 Th quivlnt is to ott ound i θ in th sm diction.