Look! Borg get upgrade already!

Transcription

1 Cancer, Partikel Terapi and PT accelerators Look! Borg get upgrade already! 1 Cancer, Partikel Terapi and PT accelerators Basic requirements to PT accelerator Accelerators for PT Siemens PT maskinen Alternativer: Kirurgi Chemo-terapi 2 1

2 Fractionated treatment Why fractionation of the treatment? For a high abrupt dose the healthy tissue is not able to repair the radiation damage (both cancer cells and healthy cells die). Cancer cells are only more sensitive to radiation at small doses (~2 Gy and less) After ~6 hours the healthy tissue have repaired most of the radiation damage. A curative treatment is divided into fractions of ~2 Gy with typically one day between subsequent treatments (5 days per week). 3 Therapeutic window Therapeutic window for curative treatment: Dose: Compromise between cure and toxicity to healthy tissue 4 2

3 Hardware for photon radiotherapy Proton therapy Bragg peak for protoner Photons ENERGY 3

4 Radiation cancer therapy Photons IMRT protons 7 Linear Energy Transfer Stopping Power 8 4

5 Dose deposition profiles Linear Energy Transfer Stopping Power 6 2 =36! 10 5

6 SpreadOutBraggPeak tumor raster scan treatment 6

7 Raster scanning 13 C therapy Heavy Ion Therapy Advantages (relative to protons): Higher LET -> larger RBE (and lower OER). Monitoring of dose deposition via PET (2 mm accuracy) Better conformity due to less radial straggling Slightly improved dose deposition for SOBP 7

8 Relative Biological Efficiency γ, p Biologisk effekt af stråling 8

9 PR 17 Comments about particle cancer therapy deposit dose in tumor but spare surrounding healthy tissue with photons, the maximal dose (determined by the surrounding tissue) is given in many (10 s of) fractions cancer cells are less resistant to radiation than normal cells with (high RBE) particles, few (1?!) fractions are sufficient with particles, additional treatment is possible IMRT redistribuerer dosis til det raske væv, men reducerer ikke integral dosis. Protoner kan halvere integral dosis Reducere risiko for sekundær cancer (BØRN) Potentiale for dosiseskalation C(p)-boost? Hypoxiske tumorer 9

10 Dose and intensity Range of Proton energy: Carbon energy: 30 cm (50-)250 MeV (100-)430 MeV/u=5GeV Dose of 2 Gy (=J/kg) in 2(10) l in 2 min. Particle intensity p in 2 min or C in 2 min Acceleratorer til PT Lineær accelerator Synkrotron Cyclotron 20 10

11 LINAC Too expensive; still? Little flexibility CERN Energy variation difficult No linacs for PT has been built Though: energy variation by LINAC 21 Varian proton facilitet ~7 facilities 11

12 IBA cyclotron facility ~30 ordrer! 23 Energy degradation Carbon? 24 12

13 OPTIVUS proton synchrotron 10m 25 Mitsubishi Electric proton synchrotron 26 13

14 HIT (Heidelberg) 27 HIT gantry 28 14

15 HIT gantry 29 Preassembly of structure in Egypt 15

16 SAG patient treatment room 31 Gantries vs. fixed beamlines Beamlines: horisontal semi-vertikal vertical 32 16

17 #=59 33 #=

18 #=16 35 Partikel terapi i DK I forbindelse med eksperimenter med cancer terapi med antiprotoner er der ved Århus Universitet lavet eksperimenter specielt med dosimetri af partikelbeams Kanon kampen! 18

19 Initial tests with 70 MeV p in Århus 37 Tests ved ASTRID Injektion af H - ved 150 kev Acceleration til MeV Stripning i elektronkøler H - + e H 0 + e + e Max strøm: få 10 6 per cycle 38 19

20 Kampen om kanonen 39 STRÅLEBEHANDLING AF PATIENT Mere end 1000 patienter/år, især børn og sværttilgængelige tumorer 20

21 DET NY UNIVERSITETSHOSPITAL I SKEJBY LAYOUT AF PARTIKELTERAPICENTER 21

22 DNCPT 43 DNCPT 22

23 Advanced pt accelerators Still River Tomotherapy 45 23