Development of New Carbon Therapy Facility and Future Plan of HIMAC

Transcription

1 Development of New Carbon Therapy Facility and Future Plan of Koji Noda Research Center for Charged Particle Therapy National Institute of Radiological Sciences

2 1. Introduction Contents 2. New Carbon-Therapy Facility (Compact Facility) 3. Future Plan of 4. Summary

3 Motivation of Compact Facility Patients Number of Carbon Therapy (June 94 Feb. 5) Highly Advanced Medical Therapy from Nov Since 1994, Cancer treatment with has been successfully progressed. Owing to accumulation of treatment number and good result of the clinical trials, the Japanese government approved the treatment as the highly advanced medical therapy in Nov

4 Design Consideration for Compact Facility How high Energy? How large Irradiation-Field Size? How much Intensity delivered? How large Facility? Based on experience at, the specification is determined!!

5 How high beam energy? ~2 8~1 16~18 24~26 Residual Range (mm) Head&Neck Brain Lacrimal gland Esophagus Lung Linver Pancreas Bone&SoftTissu Prostate Uterus Digestive duct Others Residual range of 25 mm covers almost all treatments at. Required energy: 4 MeV/n, under range loss of 25 mm due to scatterer etc.

6 How large field size? ~1 6~7 12~13 18~19 Field Diameter (mm) Head&Neck Brain Lacrimal gland Esophagus Lung Linver Pancreas Bone&SoftTissu Prostate Uterus Digestive duct Others ~2 6~7 11~12 SOBP Size (mm) Head&Neck Brain Lacrimal gland Esophagus Lung Linver Pancreas Bone&SoftTissu Prostate Uterus Digestive duct Others The field diameter more than 2 mm is large enough to cover almost all treatments in. The SOBP more than 15 mm covers treatments more than 95%.

7 How much intensity? Synchrotron 2μA ppp 22μA 163μA 181μA LINAC η=.9 η=.9 η=.7 ECR 258μA@C ppp η inj =.4 η cap η acc =.8.8=.64 η ext = pps HEBT Irra.-Port 5GyE/min/l η= pps η= pps

8 Specification 1. Ion species: high LET (1keV/μm) charged particle - Carbon 2. Range: Max. 25cm in water 3. Maximum irradiation area: 15cm square 4. Dose rate: 5GyE/min/l pps (C ions) 5. Irradiation direction : horizontal, vertical 6. Treatment rooms: 3 (H&V, H, V) 7. Irradiation technique: gating & layer stacking irradiation

9 Design and R&D for Compact Facility Beam Study Compact RF-cavity Compact Injector RFQ + APF-IH Development Irrad. Tech. Intensity (1 1 ppp) Intensity (1 1 ppp) Veritcal tune Vertical tune High-Precision MLC

10 Compact Injector Linac Cascade 1.4MW 36kW 11kW 36kW The injector linac cascade consists of RFQ and APH-IH linac. The RFQ accelerates C 4+ ions from 1 to 6 kev/n. The APF-IH accelerates them to 4 MeV/n. Both the operation frequencies are 2 MHz.

11 ECR NIRS RFQ APF-IH Analyzer Beam Test of Compact Injector Y. Iwata et al., WEPCH169 FCN2 (eμa) FC2 Transmission (%) Pick-up voltage for IH-DTL (V) Kinetic energy distribution for 12 C Transmission (%) di/de (arb. units) E (MeV/u)

12 Synchrotron Main parameters of the synchrotron. Lattice Type Maximum intensity of C 6+ Cell number Long straight section Circumference Injection energy Extraction energy Revolution frequency Emittance and Δp/p of injection beam Acceptance (after COD correction) Momentum acceptance Qx /Qy Maximum β function transition gamma ξx/ξy FODO pps 6 3.m m 4 MeV/u 14-4 MeV/u MHz 1 π mm mrad ±.2% 24/3 π mm mrad ±.4% / / /-1.5 BMP1 H-CR 2 SXF H-CR 1 V-CR 2 SXFr1 DCCT BMPf2 BMP2 ESD QDS1 V-CR 1 SXD V-CR 3 SPRN SXD H-CR 3 ESI SXDr1 SM1 SM SXDr2 BMP3 SM2 QF H-CR 6 T. Furukawa et al., NIM A562 (6) 15. Beta & Dispersion function [m] Injection BM s [m] QD V-CR 4 V-CR 6 BMPf1 Extraction FCN QDS2 RF-Cavity SXD SXFr2 RF-KO SXF H-CR 4 H-CR 5 V-CR 5 BM filling factor of 43% is much larger than that of 31% in, which brings a compact synchrotron.

13 Compact RF Cavity Un-tuned RF cavity with Co-based MA Comparison between cavity Frequency [MHz] Voltage [kv] Power [kw] Cavity size [cm] Size of PS etc M. Kanazawa et al., TUOCFI3 A. Sugiuraet al., TUPCH124 1 ~ Amp. with Tetrode Bias PS New cavity.4 ~ Transister Amp

14 Intensity Modulation f k Function Generators Voltage Controlled Amplifier VCA V AM RF Switch Circulating beam RF Amp. Kicker Electrode S. Sato et al., WEPCH17 AM Function controller Spill Beam gate Intensity Current Amp 1-6 A/V, 1kHz Extracted Beam I Ionization Chanber T Scanning Irradiation System Scanning Magnets Range Shifter I Intensity T The spot scanning and layer stacking methods require an intensity modulation. Therefore, we have studied the dynamically intensity control. This figure shows three intensity steps during 5 ms. This figure shows sinusoidal intensity wave.

15 Beam Delivery System Main monitor Scatterer Sub monitor Wobbler magnet Ridge filterflatness monitor Multi-leaf collimator Range shifter Bolus Iso-center 7265 Komori M. et al; J Jpn Appl Phys.

16 Spiral Wobbler & Raster Scanning The spiral wobbler and raster scanning method can form the irradiation field by thin scatterer compared with the conventional one. This brings the longer residual range in patient. Conventional Wobbler Spiral Wobbler Raster Scanning The spiral wobbler and raster scanning can be available a larger field even under thin scatterer. Longer residual range

17 Beam-Test Result Dose normalized by the maximum Dose normalized by the maximum.8.6 Method.4 Residual Range.2 Port Length Distance from the center [mm] Forming Time Beam Efficiency Field Shape.8.6 Power supply Wobbler Distance from the center [mm] Dose normalized by the maximum Dose normalized by the maximum Spiral Distance from the center [mm] Spiral Wobbler Raster Distance from the center [mm] Raster Scann Dose normalized by the maximum Dose normalized by the maximum Meas. Calc Meas. Calc. Distance from the center (x-axis) [mm] Distance from the center [mm]

18 Future Plan of (1) For High Accurate Treatment 3D scanning on a moving target for reducing the margin of 5-1 mm Repainting with Raster Scan & Layer Stacking Method 3D scanning on a fixed target for fitting irregular shape Spot Scanning or Raster Scanning Method For Flexible Treatment and One-day Treatment Rotating Gantry Repainting with Raster Scan & Layer Stacking Method

19 Future Plan of (2) 2 treatment rooms (H&V) with both broad beam & 3D scanning system 1 gantry room New Treatment Facility y-scan Scat/IC RGF UM 354 T. Furukawa et al., WEPCH167 Broad-beam Raster & Layer Stacking Spot Scanning Iso-Cent Broad-beam Raster & Layer Stacking

20 Summary Compact carbon-therapy facility was initiated at Gunma University from April 26: 3 years project New treatment facility with was also initiated at NIRS from April 26: 7 years project Thank you for your attention!!

21 Future Plan of (3) deg. 45 deg. y-scan Scat/IC RGF UM Iso-Cent m 7.1 m T. Furukawa et al., WEPCH167 Without Scatterer With Scatterer y [mm] y [mm] x [mm] y [mm] y [mm] x [mm] 4 MeV/n Rotating Gantry Field size: 15cm x 15cm SOBP : 15cm Range : 25cm Repainting raster scan with layer stacking x [mm] x [mm] Compensation of asymmetry distribution

22 Future Plan of (2) Experiment of spot scan for irregular shape target

23 One fraction irradiation on lung cancer The treatment period and the number of fractions have been successively reduced from 18 fractions over 6 weeks to 9 fractions over 3 weeks and further 4 fractions over one week. The end-point is single fraction. It has been carried out since April GyE (18 fraction) 94/1 ~ 97/ GyE (4 fraction) /12 ~ 3/ GyE (9 fraction) 97/9 ~ / GyE (1 fraction) 3/4 ~ 6/3

24 Gated irradiation with respiration - Irradiation system of coincident with a patient s respiratory motion - Accelerator Interlock system Gated beam extraction system (RF knockout method) Treatment control Watch & record system Gate signal generator Beam monitor Ion beam PSD Respiration waveform Reference Image Compare Positioning Image Planning simulation Positioning area Irradiation room X-ray TV Positioning system using x-ray TV images

25 Layer stacking irradiation Improvement of the irradiation accuracy Procedure 1. Mini SOBP is produced by ridge filter. 2. The target volume is longitudinally divided into slices. 3. The mini SOBP is longitudinally scanned over the target volume in stepwise manner by using range shifter. 4. At same time, the lateral field is shaped by MLC in each slice. Ridge Filter Wobbler Magnets and Scatterer Dose monitor Range shifter Multi-leaf Collimator Compensator