A retrospective pilot study of the performance of mammographers in interpreting screening mammograms

Transcription

1 Ausralian Insiue of Radiography The Radiographer 21; 57 (1): Original research A rerospecive pilo sudy of he performance of mammographers in inerpreing screening mammograms S Moran and H Warren-Forward Discipline of Medical Radiaion Sciences, Faculy of Healh Sciences, Callaghan Campus, Universiy of Newcasle, New Souh Wales 238, Ausralia. Correspondence sheila.moran@uon.edu.au Absrac Purpose: This paper provides pilo daa from one Breas Screening Program on wheher mammographers have he abiliy o review mammograms wih similar accuracy o screen readers. Mehods: The paricipan group consised of 11 mammographers (experienced in assessing images for echnical adequacy, bu no specialised raining for deecing abnormaliies) and hree curren screen readers employed a Huner BreasScreen. Fify ses of mammograms performed during 23 were used in he rerospecive sudy. The mammograms were chosen o represen a range of review oucomes. Each paricipan reviewed each se of mammograms using he BreasScreen Ausralia assessmen scale; hese resuls were hen caegorised ino wo groups Rescreen or Recall. The consensus review oucome of he original screen readers was used as he Gold Sandard. Paien oucome was assessed by following up on he resuls of any hisology or pahology ess in 23 or he 26 screening resuls. Resuls: Compared wih he Gold Sandard oucomes, he hree curren screen reader paricipans had sensiiviy values of 67%, 83% and 94%; mammographer sensiiviy values ranged from 61% o 89%. Specificiy for he screen reader paricipans was 81%, 84% and 87% and mammographers ranged from 45% o 97%. Accuracy for he hree screen readers was 76%, 84% and 9% while he mammographers aained beween 55% and 86%. Conclusion: Wihou any raining, he sensiiviy obained by hree mammographers and he specificiy obained by six mammographers were similar o hose of he curren screen reader paricipans. Accuracy raes of he mammographers indicae ha screen reading by seleced and appropriaely rained mammographers may be feasible. Inroducion More han 1.3 million women worldwide are diagnosed wih breas cancer every year. This accouns for 28% of all female cancer cases and 13.5% of all new cancers. 1 In Ausralia, breas cancer is he second mos common invasive cancer diagnosed in females; 2 i is also a leading cause of cancer deah in females. 3,4 Breas cancer deahs declined significanly in he 199s, largely due o mammographic screening (earlier deecion) and more effecive reamens. 5 Mammography is he mos common modaliy for deecion of early breas cancer and is he Gold Sandard o which oher imaging modaliies are compared. Screening mammography has been proven in clinical rials o reduce moraliy from breas cancer by a leas 3% in he over 5 age group. 6,7,8 There have been many aricles wrien over he las few years abou he need o expand he roles of radiographers in Ausralia. 9,1 There are a number of reasons for his suppor for changes o he career pahways open o radiographers. Firs here is a known shorage of radiologiss whose workloads are increasing wih new echnological advances 11,12,13 and he supply and demand of radiologiss in he fuure will be a complex issue o address. 14,15 Making use of some of he experienced radiographers in cerain specialies cerainly makes sense. Second, here are very few opporuniies for experienced radiographers o expand heir skills and pu hem ino pracice, hereby mainaining an enhusiasm for heir work. As Smih and Lewis have saed, 1 he majoriy of radiographers have few prospecs of increasing heir responsibiliy in he clinical field. There are many radiographers who do no wan o go down he pah of managemen roles, and who are frusraed a having clinical skills ha hey are no allowed o use. The shorage of radiologiss is very eviden in he field of breas imaging, mainly due o he percepion of mammography as having a high risk of liigaion, high sress levels, low re-imbursemen and o he difficulies associaed wih reading mammogram images. 16,17,18,19 Mammography is a highly specialised area: he deecion of abnormaliies on breas images is difficul because of he subley of changes in breas issue and every radiologis is likely o periodically overlook a cancer or o misinerpre a finding, paricularly if he image qualiy is no opimal. 2 Screening programmes have qualified mammographers who produce mammograms every day. Some have many years of experience of criiquing images, and may be proficien a deecing abnormaliies. Radiographer reporing has been underaken in oher counries for wo decades. Van den Biggelaar, e al. underook a review of six sudies focusing on he performance of mammographers inerpreing mammograms beween 1987 and Three sudies were from he UK and he oher hree from he USA. All he sudies were conduced in a screening seing and hree of hem measured he effec of raining on he mammographers. The resuls showed a sensiiviy range of 73% o 86% for he radiologiss and 73% o 9% for he mammographers. Specificiy for he radiologiss was 81% o 95% and he mammographers achieved 64% o 91%. I was indicaed ha raining programmes could improve he mammographers performance no only o increase cancer deecion, bu o idenify benign lesions, which would increase specificiy and keep recall raes low. 21

2 A rerospecive pilo sudy of he performance of mammographers in inerpreing screening mammograms The Radiographer 13 Table 1: BreasScreen Ausralia resuls sysem. BreasScreen Ausralia In he UK Wivell, e al. documened a rial in 22 by wo formally rained mammographers (pos-graduae cerificae in Image Inerpreaion and Analysis). The rerospecive rial showed he mammographers recalled all 59 cancers and also recalled 32 of 9 inerval cancers. The mammographers recall rae was 3.9% higher han he radiologiss. 22 The mammographers hen became prospecive second readers for 54 screening mammograms and here was no significan difference beween he radiologis readers and hese mammographers in he recall rae (4%) or cancer deecion rae (84%). 22 There has been cauious suppor for changes o Ausralian radiographers duies and responsibiliies from boh he Ausralian Insiue of Radiographers (AIR) 23 and he Royal Ausralian and New Zealand College of Radiologiss (RANZCR). 24 Ausralian evidence is needed o highligh he abiliies of radiographers and heir willingness o develop heir roles, no only for career advancemen, bu in order o provide more efficien services. This research aims o assess wheher mammographers are capable of reading screening mammograms as accuraely as screen readers. Maerials and mehods Descripion 1 Normal/No significan finding 2 Benign 3 Probably benign/indeerminae 4 Suspicious for malignancy 5 Malignan 6 Technical faul 7 Clinical recall (sympom) Ehics and recruimen Ehics approval was obained from he Universiy of Newcasle and Huner New England ehics commiees. Paricipans were issued wih a sudy idenificaion number, which was unknown o he suden researcher; however, informaion has been provided o idenify he group of screen readers (R3, R6, R1), o allow for meaningful resuls in his paper. Mammographic images The mammograms chosen were from women who aended he Huner BreasScreen programme in 23 and who had eiher received a follow-up mammogram in 25/26 or who had been diagnosed wih breas cancer in 23. Unlike a normal bach of screening mammograms, hese ses were chosen o incorporae differen caegories of lesions and differing degrees of agreemen beween he original screen readers. Of he 5 cases in he sudy, 26 women were rescreened in he normal inerval, 24 women were recalled o assessmen and 18 of hose recalled women were diagnosed wih breas cancer. All he mammograms o be read were se up on he same viewing carousels ha screen readers normally use. The carousels used were RADX Coolbrie High Inensiy Illuminaors (45 6 cd. m 2 ) wih dimmer and masking capabiliies o eliminae exraneous ligh. The viewing carousels are in a darkened room (background lighing 5 2 lux) which is away from he main horoughfare and herefore quieer and less disracing. Each carousel can hold approximaely 1 ses of mammograms. Table 2: Example of Gold Sandard calls. Radiologis 1 Radiologis 2 Radiologis 3 Gold Sandard 1 2 Rescreen 1 4 RECALL Rescreen RECALL Normal procedure was followed, so ha if any of he women had been idenified as having breas sympoms a he ime of screening (e.g. unusual pain, a lump, nipple discharge) hen he fron regisraion shee for ha episode was pu up alongside he curren sudy images. This enabled he readers o be aware of any clinical issues associaed wih ha mammogram. Any prior recall images were hung wih he previous mammogram; paricipans were no able o access he packes for heir own informaion as hese conained he 23 paien oucomes. Assessmen of screening mammograms In Ausralia, mammographic images are reviewed independenly by a leas wo screen readers who provide resuls according o he sysem used in BreasScreen Ausralia (Table 1). Each screen reader allocaes a number (#1 7) o he mammogram. The resuls from he wo screen readers are combined ino a single recommendaion. A echnical faul (#6) is usually no a full repea mammogram bu simply one or wo views ha were no of opimal qualiy. A clinical recall (#7) may resul in recall o assessmen or a leer o he woman s docor recommending furher invesigaion. Gold Sandard When boh screen readers provide a resul of #1 and/or #2 (Table 2), he woman will receive a leer recommending rouine rescreen in wo years. If boh readers allocae a value of #3, #4 or #5, he woman is recalled for furher invesigaion. If one reader indicaes a rouine rescreen and he second reader indicaes a recall, hen a hird reader is asked o review he mammogram. This hird reader is expeced o be an experienced senior breas radiologis. If eiher reader indicaes a #4 or #5, he woman is auomaically recalled wihou a hird read. The erm Gold Sandard in his conex is defined as he single recommendaion oucome afer combining he resuls of all readers (Table 2). Mehods This rerospecive sudy was underaken o allow he researchers o pilo he research mehodology and associaed daa collecion proocol. The normal resul shee was modified in order o allow readers more space o wrie commens or ask quesions as hey read each se of mammograms. This was imporan as i allowed each reader o hink ou loud and would remind hem of heir hough process when hey laer aended a review meeing. There was also space o record he lengh of ime i ook o read he mammograms (Table 3). Each reader was required o idenify he corresponding deails on he daa shee wih he correc mammogram images on he carousel. For each mammogram, he reader gave a resul code (#1 7) and for resuls ha were 3 or higher, idenified he side (L or R), he sie (#1 5) and gave a reason for he recall (#1 7). In he case of a resul of #6 (Technical recall) he readers were also required o give anoher resul as hese mammograms had already been repored on wih he available images. A sealed box was available for he readers o inser heir compleed resul shees.

3 14 The Radiographer S Moran and H Warren-Forward Table 3: Modified resul shee. Approximae ime aken Dae. Reader code Bay NAME P.I.D Uni Resul Side Sie Reason Commens Confidence Jones L 1 1 Probably cys VC/FC/NC Righ breas 5 5 Lef breas Resul Codes Reason for Recall 1 Normal 1 Circumscribed lesion 2 Benign 2 Sellae lesion 3 Probably benign 3 Lesion/mass NOS (no oherwise specified) 4 Probably malignan 4 Asymmery 5 Malignan 5 Calcificaion granular/casing 6 Technical recall 6 Calcificaion lobular 7 Clinical recall (sympoms) 7 Calcificaion oher/nos 2 Time aken (in minues) R1 R2 R3 R4 R5 R6 R7 R8 R9 R1 R11 R12 R13 R14 R: Paricipans Screen Readers Figure 1: Reading imes for 5 mammograms. The firs sep in a diagnosis of breas cancer is he percepion of an abnormaliy on he mammogram images, which resuls in a recall o assessmen. A breas cancer canno be diagnosed from a mammographic image; lesions can appear o be malignan on imaging, bu only cyology or hisopahology can provide proof of diagnosis. 25 The researcher accessed follow-up records of he women o ascerain wheher he recall had resuled in a definiive diagnosis of breas cancer via a pahologic repor. In he cases where he women had been reurned o rouine rescreen in 23, he researcher accessed he records from each woman s reurn screening episode (25 or 26) o ascerain he oucome of hose calls. Daa The informaion was enered ino an Excel spreadshee. The sensiiviy, specificiy and accuracy were calculaed and graphed. Sensiiviy Sensiiviy is a measure of he probabiliy of deecing an abnormaliy when i is presen in he woman. I is also known as he rue-posiive fracion. 26 Specificiy Specificiy is a measure of he probabiliy of a normal inerpreaion of an image when no abnormaliy exiss. This is also known as he rue-negaive fracion. 26 Accuracy Diagnosic accuracy is he number of women correcly diagnosed (rue posiives and rue negaives) compared wih he oal number of women examined. The diagnosic accuracy of he imaging sysem depends upon a number of facors including he densiy of he breas issue, he qualiy of he mammogram, he viewing condiions and he raining and experience of he reader o correcly inerpre any abnormaliy on he image. 27 Accuracy is a combinaion of sensiiviy and specificiy and provides a ruer raing of a reader s abiliies. The sensiiviy of a reader would be 1% if hey deeced every cancer presen, and heir specificiy would be 1% if hey recalled o assessmen only hose women

4 A rerospecive pilo sudy of he performance of mammographers in inerpreing screening mammograms The Radiographer 15 Table 4: Variaion of codes given for mammogram #49. Reader Side Sie Reason Resul 1 R R 2/4 1/5 4 R4 R 5 3,4 5 R5 R 1/3 3 7 R9 R 2/5 3 3 : Original readers (23) R: Paricipans Figure 2: Righ mammogram (#49) wih obvious area of ineres. 1 Sensiiviy (%) : Original readers (23) R: Paricipans GS: Gold sandard 1 2 GS R1 R2 R3 R4 R5 R6 R7 R8 R9 R1 R11 R12 R13 R14 89% 94% 1% 67% 61% 94% 72% 61% 67% 67% 72% 89% 83% 78% 72% 83% 72% Readers Figure 3: Sensiiviy in reading 5 mammograms (screen reader paricipans denoed by arrows). wih cancer presen. A good diagnosic imaging sysem is a compromise beween no missing cancers (sensiiviy) and no recalling oo many women unnecessarily (specificiy). Review The mammograms wih lower han 5% agreemen beween paricipans and he Gold Sandard, and all 18 diagnosed cancers, were criically reviewed a a meeing wih a radiologis and breas physician in aendance. Resuls Time of reading Varying degrees of experience can be assumed o resul in a wide variaion in he ime aken o read he mammograms. The imes ranged from 35 minues o 18 minues, wih a mean ime of 9 minues (Figure 1). The ages of he mammographer paricipans ranged from 25 o 29 (one only) o 5 o 59 (five paricipans). The demographic informaion included age, experience and iniial confidence levels none of which had any relaionship o he ime aken o assess he images. Measure of agreemen When reporing on a mammogram, he reader is required o provide more deailed informaion for each woman hey wish o recall for furher assessmen. This informaion consiss of which breas, he sie of he lesion and a descripion of he abnormaliy noed. Readers percepions of exacly wha and where a lesion/abnormaliy is, varies grealy. The illusraed mammogram images of a righ breas (Figure 2) show a lesion behind he nipple and slighly medial on he CC view. These images show nohing else of any ineres, and ye he resuling recall codes given for sie and reason covered almos he enire range (Table 4). Alhough he level of agreemen of classificaion varied considerably, he area of he breas issue in quesion was considered o be he same area for all paricipans. While all readers should endeavour o sandardise heir classificaions, he overall benefi o he women screened always resuls in one of wo choices Rescreen or Recall. The final level of agreemen decided on by he researchers was herefore resriced o agreemen wih he Gold Sandard only for Rescreen or Recall and he correc side. Sensiiviy The Gold Sandard used in he pilo sudy has an inheren sensiiviy of 1%; i is assumed ha he Gold Sandard deeced all he cancers. The original screen readers in 23 had sensiiviies of 89% and 94% whereas he range for he paricipan screen readers in he sudy was 67%, 83% and 94%, which indicaes here were beween 1 and 6 cancers missed ou of a oal of 18 (Figure 3). The mammographers varied from 61% o 89%, wih a median of 72%; wih beween 2 and 7 missed cancers. Remember, he mammographer paricipans have had no raining in he diagnosic assessmen of mammograms.

5 16 The Radiographer S Moran and H Warren-Forward 1 8 Accuracy (%) Specificiy (%) GS R1 R2 R3 R4 R5 R6 R7 R8 R9 R1 R11 R12 R13 R14 81% 81% 81% 97% 81% 87% 45% 78% 81% 78% 59% 65% 84% 69% 78% 84% 63% Figure 4: Specificiy in reading 5 mammograms (screen reader paricipans denoed by arrow). : Original readers (23) R: Paricipans GS: Gold sandard : Original readers (23) R: Paricipans GS: Gold sandard 2 Accuracy GS R1 R2 R3 R4 R5 R6 R7 R8 R9 R1 R11 R12 R13 R14 84% 86% 88% 86% 74% 9% 55% 72% 76% 74% 64% 73% 84% 72% 76% 84% 66% Reader Figure 5: Accuracy of reading 5 mammograms (screen reader paricipans denoed by arrow). 12 Pariipans in agreemen wih GS % Film number Figure 6: Agreemen per mammogram.

6 A rerospecive pilo sudy of he performance of mammographers in inerpreing screening mammograms The Radiographer 17 Table 5: Paricipans in agreemen wih GS (RC = Recall: RS = Rescreen). Film numbers #2 #13 #16 #22 #24 #29 #43 #44 #46 #47 23 GS resul RC RC RS RS RS RC RS RS RC RC Mammographers agree wih GS (n = 11) Screen readers agree wih GS (n = 3) resul Cancer N N N N Y 26 resul Cancer N N Y N Y N Y Y N n/a Commens? new cancer? new cancer Incorrec Side? new? missed in 23 Mos paricipans missed his Table 6: Reasons for missed cancers. Mammogram #6 #12 #17 #2 #21 #23 #26 #27 #35 #41 #47 #48 #49 Coun Circumscribed lesion (1) 7 Sellae (2) 3 Lesion NOS (3) 3 Asymmery (4) 2 Micro-calcificaions (5,6,7) 4 Mammographers who missed (n) Specificiy The Gold Sandard specificiy was 81% (Figure 4). The paricipan screen readers had specificiies of 81%, 84% and 87% and he mammographers a range of 45% o 97% (median of 78%). The mammographer wih he lowes specificiy recalled 14 of he 26 women who had no cancer. Accuracy In his pilo sudy, a reader would have o have recalled only hose 18 women who had a diagnosis of cancer o aain a 1% accuracy raing. The Gold Sandard accuracy rae was 88% (Figure 5), which is a correc diagnosis for 44 of he 5 women in he sudy. The screen reader paricipans scored 76%, 84% and 9% accuracy, while he range for he mammographers was beween 55% and 86%. Three mammographers aained equal or higher accuracy han he lowes scoring screen reader. Accuracy provides a reading of how efficien he reader is overall and while some mammographers are lagging behind he experienced screen readers, i appears ha ohers have he abiliy o deec cancers wihou excessive recalls. Agreemen per film All paricipans agreed wih he Gold Sandard on he oucome of nine ses of mammogram images, five of which were cancers (Figure 6). There were seven ses of mammograms (#2, 13, 22, 29, 43, 46 and 47) where he agreemen was less han 5%, of which one was a cancer deeced in 23 (#47). Mammograms # 2, 13, 29 and 46 were all recalled in 23; more han 5% of paricipan readers repored hese mammograms as normal or benign. No cancer was deeced a recall assessmen and all had a normal rescreen in 26 (Table 5). Mammogram #47 was also recalled in 23 and a cancer was deeced; his was missed by all he mammographers in he sudy and by one of he hree screen readers (Table 5). Mammograms #22 and 43 were boh considered normal in 23. The majoriy of paricipans disagreed wih he Gold Sandard; mammogram #22 proved o be a normal rescreen in 26. Mammogram #43 had hree screen readers and five mammographers recommend recall for he righ breas; when he woman reurned in 26 a cancer was deeced bu in he lef breas (Table 5). 26 cancers There were four women who had a cancer deeced when hey reurned in 26. Mammogram #43 has been discussed; he ohers were mammograms #16, 24 and 44. For wo of hese women (mammograms #16, 24), almos all of he paricipans agreed wih he Gold Sandard in 23; however for mammogram #16 here were wo mammographers who noed on he resul shee, he exac side and sie of he cancer deeced in 26; one of hese mammographers failed o recognise i as a cancer, and did no recommend a recall. Mammogram #24 had one mammographer who deeced an abnormaliy a he sie of he 26 cancer. These were hree differen mammographers and hese wo 26 cancers have been considered new cancers (Table 5). Mammogram #44 had wo screen readers and wo mammographers who recommended recall; wo more mammographers commened on he abnormaliy, bu failed o recognise i as malignan. These six paricipans noed he exac side and sie of he cancer deeced in 26; his could be classified as a missed cancer, which for he purpose of his research, can be defined as a falsenegaive resul wih he cancer visible in rerospec (Table 5).

7 18 The Radiographer S Moran and H Warren-Forward Discussion When conducing his rerospecive rial, he sandard achieved by he paricipans has been compared o he Gold Sandard resul in 23. This implies ha he Gold Sandard is 1% correc; however, he fac is ha no screening programme will deec 1% of he cancers 28,29,3 because all readers will, a some sage, fail o deec an abnormaliy. 17,31 This psychovisual phenomenon is one of he main reasons for he inroducion of double reading in mammography o improve he cancer deecion rae and reduce he error rae. 32,33 The advanage of employing wo or more readers has been he subjec of many papers and rials 34,35,36 and in BreasScreen Ausralia, double reading is acceped as he benchmark, where specifically rained non-radiologis readers can be employed. 29 Missed cancers Two major causes of missed cancers are inerpreaion and percepion. 37 Inerpreaion errors may be explained by readers who see he abnormaliy, bu fail o recognise i as a malignancy. The percepual error is when a lesion is eviden in he field of view, ye is overlooked by he reader, mos ofen due o busy or dense parenchyma. 37,38 The majoriy of cancers missed by he mammographers fell ino wo caegories circumscribed lesions and micro-calcificaions (Table 6), boh of which can be difficul o deec when heir densiy is similar or lower han he surrounding issue. 37,38 A rial in London in 1996 which involved over 17 mammograms 39 showed ha seven radiographers who had undergone a course in mammogram inerpreaion a a Naional Healh Service Breas Screen Training Cenre, aained sensiiviy equivalen o a single radiologis reader (73%) bu 9% lower (86%) specificiy, and ha excess recall could be limied by radiologis review of radiographer repors of poenial findings.this curren pilo sudy shows nearly 1% lower mean sensiiviy by he (unrained) mammographers compared o he paricipan screen readers; however, he loss of specificiy was equivalen o ha of he sudy by Pauli, e al. In 23 in Pisburgh, USA, Jules Sumkin and co-workers invesigaed he possibiliy of echnologiss reading screening mammograms. In a prospecive sudy, 33 echnologiss over six faciliies were required o assess over 3 mammograms in oal. They were o provide eiher a negaive resul or an indicaion ha furher procedures were necessary, and hese resuls were compared wih he radiologiss inerpreaions (82% agreemen). Tha rial showed ha, even wihou any addiional raining, hey could perform a reasonable levels of accuracy, and furher exploraion of ha concep was suggesed. 4 Disagreemen beween he echnologiss and radiologiss was greaes in cases for which he reason given by he radiologis was asymmery or archiecural disorion. Failed percepion is ofen associaed wih parenchymal disorion and high-densiy breas issue. 37,38 The mammographers in his curren pilo sudy seemed o have mos difficuly perceiving lesions ha were circumscribed; his correlaes wih percepion of masses and archiecural disorion described by Bird, e al. 37 I is widely acknowledged ha screening programmes will no deec every cancer presen, and in he UK and Ausralia, sensiiviy has been esimaed o range from 68 9%. 28,29,3 There are no Naional Accrediaion sandards for sensiiviy; however mos screening programmes aim for levels of 8 85%. 28,29,3 This curren research showed ha wo mammographers demonsraed sensiiviy of over 8%, and five oher mammographers were beween 72 8%. To he women who are screened, sensiiviy is he mos imporan aspec of heir visi if hey have a cancer, hey expec i o be deeced. If rue cancers are being missed, he screening programme is no being effecive. If any cancers were missed by he original screen readers, i would no be apparen unil he women reurned for heir nex screening or if hey were diagnosed wih an inerval cancer. Breas screening programmes in he UK have repored specificiy values of beween 82% and 97% 3 and in Ausralia, he Ausralian Insiue of Healh and Welfare (AIHW) repored similar specificiy of 8 o 95%. 28,41 Three mammographers aained over 8% wih hree ohers a 78%. If he specificiy is low, oo many women are being recalled unnecessarily. This is no only expensive bu i also can increase anxiey in he women. 42 Resuls of he curren sudy show ha seven mammographers scored over 72% sensiiviy and six obained higher han 78% specificiy; hough only wo mammographers aained boh a high sensiiviy and specificiy. The majoriy (eigh) of mammographer paricipans were somewha successful in aaining a balance beween cancer deecion and recognising a normal mammogram by achieving over 7% accuracy. All he mammographers would benefi from specialised raining o develop heir skills o discriminae beween significan and insignifican abnormaliies. The researcher has developed a raining package specifically for mammographers o assess screening mammograms. 43 This package demonsraes examples of benign and malignan lesions, and also provides guidance on how o approach assessmen in a mehodical manner. During review of he pilo sudy, i was apparen ha he majoriy of mammographers had acquired a greaer appreciaion of he difficulies of he screen reader s work and he imporance of high qualiy mammograms for accurae assessmen; his may encourage a higher sandard of image qualiy in he screening seing. The small number of mammograms in his pilo sudy may have skewed he resuls o some exen. The relaively large number of cancers may have encouraged he mammographers o deec somehing in every mammogram (more False Posiives) and for he screen readers i may have had he opposie effec (increased False Negaives) as his is no a usual screening scenario. I is noed ha he resuls of his sudy only concenraed on one BreasScreen programme and he resuls canno be generalised o oher programmes. All paricipan reader resuls were analysed on an individual basis. If he paricipans had been paired wih anoher paricipan (as is sandard pracice wih screen readers) i may have improved he oucome as compared wih he consensus Gold Sandard. Conclusion Due o a shorage of radiologiss and possible increased role expansion of mammographers, his research looked a he suiabiliy of mammographers o read screening mammograms. This could help o provide he flexibiliy when he need arises recommended in he NAS which enables oher medical personnel o repor on mammograms providing hey have he necessary raining and experience. 44 Experienced mammographers, because hey are looking a mammographic images every day, become familiar wih normal and abnormal findings. They are also involved in he recall clinics every week, where hey locae lesions by doing exra views. The fac ha some experienced mammographers may be capable of assessing breas images should encourage us o consider wheher hey could enhance he service provided by a breas screening programme. This sudy has shown ha, wihou any formal raining, some

8 A rerospecive pilo sudy of he performance of mammographers in inerpreing screening mammograms The Radiographer 19 mammographers have shown promise of being able o read mammograms wih accuracy equivalen o ha of curren screen readers. Since compleion of he pilo, a full rerospecive sudy has been compleed, wih measuremen of iner and inra consisency of reader accuracy. The raining package will be expanded and will possibly be offered o mammographers hroughou Ausralia. This research projec will also conduc a prospecive sage, which will consis of seleced mammographers assessing curren mammograms under he same condiions as he radiologiss. This sudy will concurrenly examine he differences beween analogue and digial images and he difficulies of changing modaliies. There is no poin in pursuing his expansion of roles if mammographers are no ineresed; herefore, a quesionnaire has been disribued Ausralia wide, o ascerain he houghs and opinions of mammographers currenly working. I is imporan o discover in which direcion hey have mos ineres. Acknowledgemens I would like o exend my hearfel hanks o my colleagues a Huner Breas Screen (now known as BreasScreen New Souh Wales Huner New England) who enhusiasically paricipaed in his rial and donaed heir ime and effor. My hanks also go o he Ausralian Insiue of Radiography for he 27 Diagnosic Research Scholarship award. This enabled me o presen he findings from his pilo sudy a he 5h ASMMIRT conference in Melbourne in April 28. The auhors Sheila Moran MRS Associae Professor Helen Warren-Forward (Supervisor) BSc, PhD References 1 Inernaional Agency for Research on Cancer. New European cancer figures. 27 Available online a: [verified 28]. 2 BreasScreen Ausralia. Available online a: [verified February 21]. 3 AIHW. Breas cancer in Ausralia: an overview, 26: Ausralian Insiue of Healh & Welfare and Naional Breas Cancer Cenre AIHW. Cancer in Ausralia: an overview, 28. Canberra Imaginis. Breas cancer cases/deahs per year. 27. 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