Cancer Treatment by Charged Particles - Carbon Ion Radiotherapy Part 2

Transcription

1 NIRS Cancer Treatment by Charged Particles - Carbon Ion Radiotherapy Part 2 Takeshi Murakami Research Center of Charged Particle Therapy National Institute of Radiological Sciences

2 Medical application of accelerators Requirements 1. Stable, reliable, easy operation and maintenance Ion source, injector, main ring, irradiation system etc. (same way as water from a faucet ) 2. Precise irradiation system Patient positioning Respiration motion compensation Satisfied! 3. Small inexpensive facility! accelerators Irradiation system???

3 Design Consideration for Compact Facility What Ion Species? Carbon! 1. Scanning or Broadbeam? 2. How high the Energy? 3. How large the Irradiation-Field Size? 4. How high the Intensity? 5. Consequently, how large the Facility? Based on experience at, the specification is determined!!

4 How high a beam energy should be? ~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, with an additional range of 25 mm required for the scatterer etc.

5 How large a field size should be? ~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 of 2 mm in diameter is large enough to cover almost all treatments in. The SOBP with a depth of 15 mm covers treatments more than 95%.

6 Specification of the Compact Carbon- Therapy Facility 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: 5Gy/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 1. Accelerator systems and Irradiation systems : High reliability, stability, reproducibility, easy operation, easy maintenance and absolute safety 2. The other requirements : - Precise beam delivering - Easy beam tuning in a short time within a few minutes - Accurate dose measurement and control - Fail-safe system Optimize for Carbon beams Furthermore how can we reduce the size?

7 Compact Therapy Facility Detailed design and R&D was completed in FY 5. Its size is downsized to 1/3 compared with. Train

8 Compact Injector Linac Cascade APF IH-DTL An ECR ion source employs permanent magnets. The injector linac cascade consists of RFQ and APF-IH linac. The RFQ accelerates C 4+ ions from 1 to 6 kev/n. The IH linac accelerates them to 4 MeV/n. The operation frequency is 2 MHz for both linacs.

9 Development of ECR source Compact ECR ion source with all permanent magnets 1. Mirror magnetic field was copied from NIRS-ECR 2. Traveling-Wave-Tube amp. was chosen for fixed magnetic field 3. Enough insulation for carbon ion production Diameter Mirror field Permanent magnet Max. surface field Microwave 3mm.87,.25,.59 T NdFeB 1.1 T 8-1 GHz, 3 W M. Muramatsu will contribute in ICIS5!

10 di/de (arb. units) FCN2 (eμa) Transmission (%) NIRS Beam Test of Compact Injector 45 1 ECR RFQ APF-IH Analyzer FC2 Transmission (%) Pick-up voltage for IH-DTL (V) 45 Kinetic energy distribution for 12 C m E (MeV/u)

11 Lattice Type Maximum intensity of C 6+ FODO pps Cell number 6 Long straight section 3.m 6 Circumference 61.5m Injection energy Extraction energy Revolution frequency Emittance and Δp/p of injection beam Acceptance (after COD correction) Specification 4 MeV/u 14-4 MeV/u MHz 1 π mm mrad ±.2% 24/3 π mm mrad Momentum acceptance ±.4% Qx /Qy /1.23 Maximum β function 11.5/13.4 transition gamma 1.72 ξx/ξy -.5/-1.5 Shorten the straight line. V-CR 1 H-CR 1 SXFr1 DCCT BMP1 BMPf2 V-CR 2 H-CR 2 SXF ESD BMP2 QDS1 SXD V-CR 3 SPRN ESI SXDr1 SXD Synchrotron SM H-CR 6 H-CR 3 SXDr2 BMP3 SM1 SM2 QF BM 5m Injection QD V-CR 6 BMPf1 QDS2 FCN RF-Cavity H-CR 5 V-CR 5 SXD SXFr2 RF-KO SXF H-CR 4 V-CR 4 Extraction

12 Compact RF Cavity Un-tuned RF cavity with Co-based MA Comparison between cavity New cavity Frequency [MHz] 1 ~ 8.4 ~ 7 Voltage [kv] Power [kw] 15 8 Cavity size [cm] Size of PS etc Amp. with Tetrode Bias PS Transister Amp

13 Gunma University Heavy-Ion Medical Center

14 HIMAT Tosu near to Tosu high way junction Fukuoka To Fukuoka Shin-Kansen Railway Shin-Tosu SAGA-HIMAT To Kumamoto, Kagoshima To Saga, Nagasaki Adjacent to Shin-Tosu Station

15 Facilities in Japan Gunma (21) Tosu (213) Heavy ion Heavy ion (under construction) Proton Kanagawa (214) Chiba (1994) Proton (under construction) Other plans (not funded) Hyogo (21)

16 Heavy ion radiotherapy worldwide Darmstadt Heidelberg Wiener Neustadt Lanzhou Busan Lyon Pavia Penang Gunma Chiba Hyogo Tosu Kanagawa Rochester Shanghai Heavy ion Heavy ion (under construction) Heavy ion (planning) Proton Proton (under construction) Taipei

17 Quick change of the target (a) (b) Change of target position and 84cc 69cc Large change of target size and shape during the treatment process Change the treatment planning, and bolus, collimator -> 4-5 days are necessary for machining, transport, inspection

18 Motivation of New Treatment Facility 1 day! 1 day treatment is possible Adaptive Cancer Treatment diagnosis and treatment in a short period

19 Irradiation Methods Broad beam Wobbling magnets Scanning scatterer Ridge filter Bolus Patient collimator Scanning magnets range shifter

20 Comparison of scanning and broad beam method Scanning Broad beam Dose distribution excellent good Moving target No Yes Irradiation time long short Dose control Elaborate Easy Bolus, collimator No Yes Beam position <.2mm ~ 2 mm Beam size Control No control Intensity Low High scanning long treatment time no moving target sensitive to the device error Broad beam: matured technology! New scanning system must be developed.

21 Simulation of moving tumor irradiation Irradiation on Moving Tumors Non-gating Example: Φ4mm spherical target s( t) cos t /3, 2s 4 Motion:7mm in gate -4 Gating Gating with rescanning (8 times) In order to avoid hot/cold spot due to target motion, we decided to employ gating method with rescanning

22 R&S of Fast Scanning System Scanning R&D port SB course 1. Fast scanning system 2. Respiratory motion New control system

23 Fast Scanning Example: FT SMx -5-5 SMy Beam 5 5

24 num. of port NIRS First half of cc Manipulate synchrotron extraction acceleration injection Operation pattern of synchrotron Fixed period time PTV (cc) extraction acceleration 1 spill (2 1 1 particles) corresponds to 15 GyE on 3cc target! injection Extension of the flat-top time -> Most of the treatments require 1 spill!

25 Beam position (mm) Beam size (mm) Intensity Extension of the flat-top Position, size, intensity -> stable? Horizontal Vertical Horizontal Vertical Time (s) Position Size Intensity

26 SMx SMy Scanning with extended Flat-Top Fluorescent screen Beam Syn. BM 1. Treatment planning for fast scanning 5 2. Modification of acc. operation 2 3. Fast scanning magnet 1 plan We can save the dead time of synchrotron operation.

27 I(BM) (A) NIRS 11-steps Energy Operation ms 6 15ms 11 4ms t (ms) step Energy: 43, 4, 38, 35, 32, 29, 26, 23, 2, 17 and 14 Tune: (Q h, Q v ) = (3.68, 3.11)

28 New Particle Therapy Research Facilities 3D Scanning with Gating (H&V): 2 rooms Rotating Gantry : 1 room Research Building for Charged Particle Therapy building Hospital New treatment facility Wall RGF QM PRN1 SMx SMy PRN2 RSF 3D Scanning 9. m Monitors 1 2m Iso-center

29 burden on patients Rotating Capsule complicated treatment planning due to deformation of organs GyE (18 fraction) 94/1 ~ 97/ GyE (4 fraction) /12 ~ 3/ GyE (9 fraction) 97/9 ~ / GyE (1 fraction) 3/4 ~ 6/3

30 Beta and dispersion function (m) Beta and dispersion function (m) Beta and dispersion function (m) NIRS Rotating Gantry with Super- Conducting Magnets (a) x y D x 3D scanning Field size: Max SOBP: 15 mm 15 mm 1 Max energy: 4 MeV/u -1 5 (b) respiratory mot.: OK 4 3 ~25 ton (c) s (m)

31 New Particle Therapy Research Facilities

32 New Particle Therapy Research Facilities 1F

33 New Particle Therapy Research Facilities 1F

34 New Particle Therapy Research Facilities 1F

35 New Treatment Couch, Robotic Arm

36 Requirements for the therapy at - Ion species: high LET (1keV/mm) charged particles He, C, Ne, Si - Range: 3cm in soft tissue 43MeV/u (C) 8MeV/u(Si) - Maximum irradiation area: 22cm in diameter - Dose rate: 5GyE/min pps - Beam direction: horizontal, vertical, etc... -> large accelerator, being rare in the world

37 Weekly Schedule Upper Ring Lower Ring Linac Mon Tue Wed Thu Fri Sat Sun Monday Maintenance Weekdays (Daytime) Therapy Weekdays (Night) and Weekends Experiments Application Therapy Biology Physics or others Maintenance (No Beams)

38 Specifications of the facility Ion source Injector PIG, 1GHz-ECR, and 18GHz-ECR 8 kev/nucleon Ion species: p He to to Xe Ar RFQ linac (.6 m f x 7.3 m long) 8 kev/ nucleon Alvarez linac (2.2 m f x 24 m long) 6 MeV/ nucleon Main accelerator Synchrotron (42 m ) 2 rings 1-8 MeV / nucleon Irradiation rooms 3 treatment rooms 4 experiment rooms 2 experiment rooms Time Sharing Acceleration + Pulse Magnets repetition rate: 3.3 seconds General-physics experiment room Secondary beam experiment room Biology experiment room Medium-energy experiment room

39 13m Pulse operation Cut-away view of Time sharing acceleration 3 ion sources Two identical rings Clinical trials using carbon beams (Heavy Ion Medical Accelerator in Chiba)

40 Experiment rooms ( B2F) Medium-energy experiment room Secondary beam experiment room General-physics experiment room

41 General-Physics Experiment Room PH2

42 Biology experiment room ( 2F) Biology experiment room

43 Biology Experiment Room samples

44 3.3sec NIRS C Ar Xe Time Sharing Acceleration Injector MEXP Direct use Upper Ring Lower Ring

45 Hours in FY211 NIRS The hours of operation, FY Linac Upper Ring Lower Ring

46 Hours in operation NIRS Beam Time for Physics and Biology Biology Physics Year Cumulative time

47 Number of proposals in each year Number of accepted proposals Medical Biology Physics Year

48 Number of Participants NIRS Number of Participants in the Basic Science Programs Outside users Foreigners Inside users