Development of beam delivery systems for proton (ion) therapy

Transcription

1 7th 28th of July 213, JINR Dubna, Russia Development of beam delivery systems for proton (ion) therapy S t u d e n t : J o z e f B o k o r S u p e r v i s o r : D r. A l e x a n d e r M o l o k a n o v jozef.bokor@stuba.sk Dzhelepov Laboratory of Nuclear Problems

2 CONTENT PART I F u l l y a c t i v e b e a m d e l i v e r y s y s t e m s i n ion t h e r a p y M o d e r n i o n t h e r a p y F u l l y A c t i v e S y s t e m s + R o t a t i n g G a n t r y PART II R o t a t o r m e t h o d S i m u l a t i o n s o f t h e r o t a t o r l a t t i c e s 1

3 Fully active beam delivery systems! a pencil-like beam! an accelerator a treatment room over the whole PTV PTV divided in layers with the equal beam energy layer covered by a grid of picture points (voxels) delivering the dose sequentially to voxels PART I (reproduced from [2]) 2

4 Current development of beam delivery systems in modern proton (ion) therapy Fully Active Systems + ROTATING GANTRY + BM bending magnet, Q - quadrupole an ambition to irradiate the tumor from any side a suitable size at the treatment point: typically 4 1 mm still not standard devices for hospital-based ion therapy (size, weight,...) PART I 3

5 The aim of the project the ion-therapy beams symmetric assymmetric slow resonant extraction Assymetric ion-therapy beams from the medical synchrotrons! the input beam parameters at the gantry entrance as a function of the gantry rotation Angular dependance Input beam parameters PART I Output beam parameters 4

6 ROTATOR METHOD ROTATOR - a dispersion-free straight-section - between the exit of the fixed beam-line and the gantry entrance - compact structure the shorter, the better a set of symmetrically grouped quadrupole magnets PART II 5

7 set of symmetrically grouped quadrupoles M ROT r11 r12 r21 r22 M the most preferable r 11 r12 r21 r22 x M x rotated by a half of the gantry angle the most preferable two co-ordinate system rotations REMOVING OF THE ANGULAR DEPENDANCE PART II the beam parameters at the entrance to the gantry follow the gantry rotation 6

8 FIRST rotator: 215 MedAUSTRON, Wiener Neustadt (Austria) 7 quadrupoles (45 cm) a total length - 11 m Simulations of my project: the most preferable TRANSFER MATRIX WinAGILE software changing of the rotator desing changing of the length of quadrupoles decrease the number of quadrupoles Optimize and design the ROTATOR lattices PART II 7

9 8 PART II MY RESULTS seven 45 cm long quadrupoles 4 quadrupole families (Q1=Q7, Q2=Q6, Q3=Q5 and Q4) M ROT_1 and M ROT_ M ROT _1 ] 1/ 3 [m 3 [m] ] 1/ 3 [m 3 [m] 1 1 M ROT _ 2 A POINT-TO-POINT IMAGING LATTICE A PARALLEL-TO-POINT IMAGING LATTICE MedAUSTRON, Wiener Neustadt

10 M ROT1 POINT-TO-POINT IMAGING LATTICE the length of rotator 1,15 m triplet singlet - triplet (simulated in WinAGILE) M ROT2 PARALLEL-TO-POINT IMAGING LATTICE the length of rotator 7,25 m doublet triplet - doublet (simulated in WinAGILE) PART II 9

11 D r. A l e x a n d e r M o l o k a n o v T h e U n i v e r s i t y C e n t e r a n d J I N R D o r o t a B o r o w i c z a n d M a g d a l e n a M a z u r Reference: [1] CHU, W.T., LUDEWIGT, B.A., RENNER, T.R.: Instrumentation for Treatment of Cancer Using Proton and Light-Ion Beams [2] SCHARDT, D., ELSÄSSER, T., SCHULZ-ERTNER, D.: Heavy-ion tumor therapy: Physical and radiobiological benefits 1

12 7th 28th of July 213, JINR Dubna, Russia Thank you for your attention.

13 PART II 3

14 PART II 3

15 Point-to-point imaging lattice

16 Parallel-to-point imaging lattice:

17 Beam delivery systems in ion therapy a dose-to-tumor conformity non irradiated any surrounding healthy tissue never possible a technological development in beam-delivery systems transport and distribution of the beam over the planned target volume (PTV) fully passive systems fully active systems other solutions in between these two extremes ([1] Chu et al.) PART I 3

18 Fully passive systems passive field shaping material elements scatterers > range modulator > range shifter > collimator > compensator (bolus) drawbacks: multiple scattering, range straggling, limitations of SOBP width, PART I (reproduced from [2]) 3

19 The important parameters of ion-therapy beams: 1. the ion-beam range the kinetic energy: the shorter ranges, the lower energies ranges in tissue up to 3 cm 22 MeV/u (protons, He ions) 43 MeV/u (carbon ions) 2. the ion-beam intensity: PART I 1 8 to 1 1 particles/s the dose-rate of few Gy/min

20 Real space 3 coordinates [x, s, z] Phase space 6 coordinates 3 coordinates position [x, s, z] 3 coordinates momentum [p x, p s, p z ] Trajectory of single paerticle in vertical plane in real space Trajectory of single particle in vertical plane in phase space A Emmitance of ion-beam cross section of the whole ionbeam in vertical plane in phase space

21 f ( 11 s 22 f ( s) ) - dimension of ion-beam parameter - divergence of ion-beam parameter σ v σ v SIGMA MATRIX f ( 11 s ) Emmitance Twiss parameters

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23 ION THERAPY treatment of localized deep-seated tumors photons (X-rays or gamma), electrons, protons, heavy ions ION THERAPY vs. CONVENTIONAL THERAPY ions (1 Z 6) vs. photons, electrons The 5th years (proton therapy) Up to now (carbon therapy) European pioneering ion-therapy facilities: Paul-Scherrer-Institute Villingen (PSI) in Switzerland Gessellschaft für Schwerionenforschung Darmstadt (GSI) in Germany Future facility (215): MedAustron in Wiener Neustadt, Austria PART I

24 How can we get the therapy beams? 1. Conventional radiotherapy: electron LINACs Linear Accelerators linear resonance accelerating structure electron or X-ray beam ( modified from [2] ) 2. Ion therapy: Circular Accelerators Cyclotrons Synchrotrons PART I

25 Cyclotron: static magnetic field an opened spiral-like desing orbit the higher kinetic energy, the larger radius of trajectory energies up to 1 MeV/u proton therapy Synchrotron: heavier ions higher energies time-varying magnetic field a closed desing orbit carbon-ions therapy PART I

26 Physical principles of ion therapy interaction of ionizing radiation (protons and heavier ions) with cancer cells damage of DNA- structure in the cancer cells STOP growing and dividing a big advantage using heavy charged particles a favorable Bragg curve What s the BRAGG CURVE? PART I 2

27 PART I Depth-dose profiles of 6 Co γ-radiation, megavolt photons, and 12 C ions in water (reproduced from [1]). 3