Presentation is loading. Please wait.

Presentation is loading. Please wait.

Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 1 Monte Carlo simulation for treatment planning in conventional radiotherapy.

Similar presentations


Presentation on theme: "Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 1 Monte Carlo simulation for treatment planning in conventional radiotherapy."— Presentation transcript:

1 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 1 Monte Carlo simulation for treatment planning in conventional radiotherapy and in hadrontherapy Faiza Bourhaleb Dipartimento di fisica sperimentale Università degli studi di Torino

2 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 2 index General description of a Monte Carlo for Treatment Planning Monte Carlo validations. Practical example of treatment planning with MC: modeling and verification in hadrontherapy. Radiobiology and Monte Carlo. Conclusion

3 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 3 General description of a Monte Carlo for Treatment Planning

4 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 4 Beamline modeling Patient data Optimized TP ANCOD++ Analytical TPS MC of the TP Patient modeling MC for BDL ScoringCutoffs General description of a MC for TP verification Particles Transport 1 2 3 4

5 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 5 GEANT3 / GEANT4 Fluka / Fluka++ EGS / EGS4 MCNP / MCNPX ETRAN ITS PENELOPE VMC (Voxel Monte Carlo) / VCM++ 4 Phases of a MC => Packages used for Monte Carlo use to verify the TPS

6 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 6 Electron and Photons: Physics is very similar in most MC codes for electrons and photons transport. Multiple scattering for e- is very important. Proton and Carbon ion: Physics is similar but for carbon ion the nuclear interaction and so the fragmentation are very important. (Scattering + stragling effects) Particle transport modeling

7 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 7 Read and conversion CT 3D construction  CT input HU  Density+ Tissues specification PS: beam type dependent Patient modeling

8 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 8 Primary source Upper part: components remaining Fixed (Patient not depending). It is modeled only once  Phase space file Secondary source The phase space file is used as input for the transport of patient dependent beam modifiers  Virtual Source Model (parameterization of a phase space file consisting of several sub- sources  particle generator for MC ) Primary Source Secondary Source Beam Line Modeling

9 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 9 Limitation on the voxel grid for the simulation Conversion to water-equivalent Cutoffs (Energies, histories, particles considered…..) Scoring / Cutoffs

10 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 10 Validation of the Monte Carlo simulation

11 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 11 Light ion fragmentation reactions –Attenuate the primary beam –Lead to a build up of low Z reaction products –Long range fragments deposit dose beyond maximum range of carbon beam Treatment planning –Physical beam model must consider fragmentation in addition to scattering and ionization Fragmentation of light ion

12 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 12 Analytical –Transport equation based on experimental cross sections in water (GSI) Monte Carlo –Increased interest for treatment planning exploiting parallel computing techniques Fragmentation of light ion

13 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 13 –PHITS (JAERI-Japan) (Particle and Heavy Ion Transport code System) –SHIELD-HIT (Karolinska / Russian Acad. Of Sciences) –FLUKA –GEANT4 (4.6.2) Binary cascade model of light ion fragmentation Use of GEANT4 to simulate light ion fragmentation experiments for the purpose of verification Codes handling fragmentation

14 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 14 Simulation of simple water tank Physical beam model used in treatment planning –Energy deposition w. depth for carbon beams in water –Extensively validated with experimental data (GSI) Test 1 depth

15 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 15 Test 1

16 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 16 Schall et al 1996 (GSI) –Fragmentation of light ion beams in water –Yield of fragments (Z > 4) with depth Test 2

17 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 17 Ionisation Chambers 90% Ar, 10% CH4, 1 atm t=50cm  E detector 670 MeV/u Target 1 o beam diagnostics H2O t=0-25 cm Test 2

18 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 18 C 12 46% Test 2

19 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 19 Gunzert-Marx et al 2003 (GSI) –Fragmentation of a carbon beam in water –Spectroscopy of light fragments (A < 4) Test 3

20 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 20 Water t=13 cm NE102 t=9mm BaF 2 t=14.5cm  E-E detector 3m C 12 200 MeV/u Target Test 3

21 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 21 neutrons protons deuterons Test 3 tritons

22 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 22 helium-3 alpha

23 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 23 Practical example of Monte Carlo for treatment planning in hadrontherapy: modeling and verification.

24 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 24 Hadron beams

25 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 25 Scanning magnets Synchroton Linac Carbon source Proton source Monitoring system Z Ec dE/ dz Active scan tecnique

26 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 26 Simulation with GEANT4 for the beam delivery line consisting of : – monitoring system –Ripple filter Modeling of Beam Delivery Line

27 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 27 look-up tables of the inv. PS from MC Proton beams Carbon ion beams Modeling of Beam Delivery Line

28 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 28 Patient modeling and conversion this work = Jäkel et al. Maximum number of materials are defined. PS: We usually use the CT resolution for the simulation different from the TP matrix. simulation.

29 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 29 Parameters of a specific TP optimized to use as input for the MC TP –Positions of the sources –Kinetic energies for single beams –Direction of the Field –Angles of single beams –Optimized Fluences Treatment planning verification

30 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 30 Carbon Ion beams Proton beams Treatment planning verification

31 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 31 Radiobiology and Monte Carlo simulation

32 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 32 Dose [Gy] Depth [mm] TRiP (GSI)

33 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 33 Sampling data inside a MC code using the LEM (or an hybrid) Principles of Local Effect Model (LEM) Biological effect completely determined by the local distribution of dose inside the cell nucleus Homogeneous cell nucleus with constant density and radiosensitivity Locally, the effect of ions can be evaluated using the X-ray Linear Quadratic model: Radiobiology and Monte Carlo simulation Alpha Carbon ions

34 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 34 Radiobiology and Monte Carlo simulation What we can do with MC for the Radiobiological part? N Depth [mm] Ed [keV] Depth [mm] E d [keV]

35 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 35 “Data – Flow” MC simulations (Geant) Ion tracks Kraft/Scholz model  (RBEsoft) Survival curves (α,β) Analytical functions Lookup tables TPS (Ancod++) RBE Radiobiology and Monte Carlo simulation

36 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 36 Radiobiology modeling  TP with the biological optimization how can we verify?? Radiobiology and Monte Carlo simulation

37 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 37 Conclusion

38 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 38  MC for hadron beams with Geant4 fully validated  Experiments of ion fragmentation in tissue substitutes useful for further verification studies  MC for radiobiology Biological Monte Carlo Treatment Planning (BMCTP)!?

39 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 39 References The Dosimetry of Ionizing Radiation, edited by Kase, Bjärngard, and Attix, Academic Press, 1990. Dr. Schardt and Dr. Gunzert-Marx of GSI for experimental details and data Dr. J.P. Wellisch and Dr. G. Folger of the GEANT4 hadronic physics group Sven O. Groezinger of GSI for carbon therapy images M. Kraemer et al (TRiP) M. Scholz et al for the Local effect Model (LEM) A treatment planning code for inverse planning and 3D-optimization in hadrontherapy. (F Bourhaleb et al) paper in preparation… Knowledge F. Marchetto 2, Iwan Cornellius, Andrea Attili 2, Roberto Cirio 2, Cristiana Peroni 1 1 Dipartimento di fisica sperimentale, Università di Torino 2 Istituto Nazionale di Fisica Nucleare (INFN), Torino.

40 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 40 Thanks for your attention

41 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 41 Model Verification Simulate fragmentation experiments Schall (GSI): Fragment yields (Z>4) for varying thickness water target Matsufuji (NIRS): fragment yields (Z>1) for varying thickness PMMA target Gunzert-Marx (GSI): fragment spectroscopy and angular dependence (n,p,d,t,He-3,  )

42 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 42 G4 Ion Physics G4MultipleScattering G4ionIonisation G4HadronInelasticProcess G4TripathiCrossSection G4IonsShenCrossSection G4BinaryLightIonReaction

43 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 43 Schall et.al. 1996 Beam : C-12 676 AMeV Target : H 2 O (variable thickness, t) Detection system : Ionisation Chamber f(  E) Information : N(Z,t) /N o

44 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 44 1. Results & Discussion  X peak mm  E peak %  E int % GEANT42.044.1 SHIELD-HIT2.0N/A3.0


Download ppt "Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 1 Monte Carlo simulation for treatment planning in conventional radiotherapy."

Similar presentations


Ads by Google