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Monte Carlo simulation for treatment planning in conventional radiotherapy and in hadrontherapy

Monte Carlo simulation for treatment planning in conventional radiotherapy and in hadrontherapy. Faiza Bourhaleb Dipartimento di fisica sperimentale Università degli studi di Torino. index. General description of a Monte Carlo for Treatment Planning Monte Carlo validations.

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Monte Carlo simulation for treatment planning in conventional radiotherapy and in hadrontherapy

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

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

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

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

  6. Particle transport modeling • 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) 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 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici

  8. Beam Line Modeling Primary Source • 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 ) Secondary Source Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici

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

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

  11. Fragmentation of light ion • 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 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici

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

  13. Codes handling fragmentation • 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 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici

  14. depth Test 1 • 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) Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici

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

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

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

  18. Test 2 C12 46% Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici

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

  20. Test 3 DE-E detector Target 3m C12 200 MeV/u BaF2 t=14.5cm NE102 t=9mm Water t=13 cm Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici

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

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

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

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

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

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

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

  29. Treatment planning verification • 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 Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici

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

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

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

  33. Alpha Carbon ions Radiobiology and Monte Carlo simulation 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: Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici

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

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

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

  37. Conclusion 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)!? 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. Marchetto2, Iwan Cornellius, Andrea Attili2, Roberto Cirio2, Cristiana Peroni1 1 Dipartimento di fisica sperimentale, Università di Torino 2 Istituto Nazionale di Fisica Nucleare (INFN), Torino. Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici

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

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

  43. Schall et.al. 1996 • Beam : C-12 676 AMeV • Target : H2O (variable thickness, t) • Detection system : Ionisation Chamber f(DE) • Information : N(Z,t) /No Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici

  44. 1. Results & Discussion Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici

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