The Hadrontherapy Geant4 advanced example by X0Nn69I


									         The Hadrontherapy Geant4
             advanced example
          P. Cirrone, G. Cuttone, F. Di Rosa, S.
              Guatelli, M. G. Pia, G. Russo
          4th Workshop on Geant4 Bio-medical Developments,
                       Geant4 Physics Validation
                     INF Genova, 13-20 July 2005

Susanna Guatelli
Scope of the hadrontherapy Geant4 application
•   Model a hadrontherapy beam line,
                                                            Modulator &
     – Donated by CATANA                      Ligth
     – Based on the CATANA beam line at       field
       INFN LNS                                             shifter    Scattering
                                          Laser                         system
•   Calculate the energy deposit in a

•   Dosimetry study

     Susanna Guatelli
                     Software process
• The development of the hadrontherapy Geant4
  application follows an iterative-incremental

• Software process products:
  – User Requirements document
  – Design
  – Documentation about the implementation is regularly

  Susanna Guatelli
          The Hadrontherapy advanced

• Documentation of the example:

• Code review of the example in occasion of
  the last Geant4 public release (7.1)

• Other changes: functionality added

Susanna Guatelli
         Primary particle


    Physics List

Susanna Guatelli   Analysis
               Simulation components
•   Primary particles
•   Physics List
•   Detector Construction
•   Energy deposit
•   Stepping action
•   Analysis

Susanna Guatelli
      Primary particles
  • The primary particles are protons generated with
    initial energy, position and direction described by
    Gaussian distributions
Particle     Proton
                                                                   • The primary particle
              Mean position    (x = -3428.59 mm, y = 0., y = 0.)   component is provided
              Sigma position   (0., 1. mm, 1. mm)                  of a messenger
Direction     Mean direction   (1., 0., 0.)
                                                                   • It is possible to
              Sigma position   (0., 0.0001, 0.0001)
                                                                   change these
Energy        Mean energy      63.45 MeV                           parameters interactively
              Sigma energy     400 keV

      Susanna Guatelli

The user can choose:
• to activate EM
  physics only
• to add on top the
  hadronic physics
• to activate
  alternative models
  for both EM and
  hadronic physics                    Modularised physics component

        Particles: p, d, t, α, ions, e-, e+, pions, neutrons, muons
    Susanna Guatelli
                     EM Physics models
• The user can choose to activate for protons the following
  alternative models:
   –   Low Energy - ICRU 49,
   –   Low Energy - Ziegler77,
   –   Low Energy - Ziegler85,
   –   Low Energy Ziegler 2000,
   –   Standard

• The user can choose for d, t, α, ions the alternative models:
   – Low Energy ICRU,
   – Standard

• In the case of Low Energy Physics, also the nuclear
  stopping power is active
  Susanna Guatelli
                   EM Physics models
 • The user can choose to activate for e-:
       – LowEnergy EEDL,
       – LowEnergy Penelope,
       – Standard

 • The user can choose to activate for e+:
       – LowEnergy Penelope,
       – Standard

 • The user can choose to activate for gamma:
       – LowEnergy EPDL,
       – LowEnergy Penelope,
       – Standard
Susanna Guatelli
                   Hadronic physics
• Elastic scattering

• Inelastic scattering
      – Alternative approaches for p, n, pions
      – LEP ( E < 100 MeV) and Binary Ion model ( E >
        80 MeV) for d, t, α

• Neutron fission and capture

Susanna Guatelli
                        Hadronic physics list
   The user can select alternative hadronic physics lists for
                 protons, pions and neutrons
                               + default evaporation
                               + GEM evaporation
• Precompound model            + default evaporation + Fermi Break-up
                               + GEM evaporation + Fermi Break-up

• Binary model + Precompound model ( with all the option showed
  above )

• Bertini model

     Susanna Guatelli
  Detector Construction
• Detailed description of the hadrontherapy beam line in terms
  of geometrical components and materials

                        The user can change geometrical parameters
                        of the beam line through interactive

                                 • The modulator is modeled
                                 • The user can rotate it between
                                 different runs

     Susanna Guatelli
   Calculation of the energy deposit
• The energy deposit is calculated inside a water
  phantom (size: 20 mm) set in front of the
  hadrontherapy beam line

• The phantom is gridded in 80 x 80 x 80 voxels
  along x, y, z axis

• The energy deposit of both primary and secondary
  particles is collected in the voxels

  Susanna Guatelli
• Threshold of production of secondary
  particles: 10 * mm

• Cut per region fixed in the sensitive detector:
  0.001 mm for all the particles involved
      – More accurate calculation of the energy deposit

• Max step fixed for all the particles in the
  sensitive detector = 0.02 cm

Susanna Guatelli
                  Result of the simulation
• Energy deposit in the phantom

• Bragg Peak along the axis parallel to the beam line (x axis)

•   Energy deposit of:
     –   secondary protons
     –   Electrons
     –   Gamma
     –   Neutrons
     –   Alpha
                             Proton beam
     –   He3
     –   Tritium
     –   Deuterium
along the x axis                                         x
    Susanna Guatelli
                     Stepping action
The user can retrieve useful information at the level of the
  stepping action:

• The total number of hadronic interactions of primary
  protons in the phantom as respect to the electromagnetic

• Which and how many secondary ions are produced in the

• The energy distribution of the secondary particles produced
  in the phantom is retrieved

  Susanna Guatelli
• Analysis tools: AIDA 3.2 and PI 1.3.3

• The output of the simulation is a .hbk file with
  ntuples and histograms containing the results
  of the simulation:
      – Energy deposit in the phantom
      – Energy deposit of secondary particles in the
      – Energy distributions of secondary particles
        originated in the phantom

Susanna Guatelli
  Future developments of the Geant4
   hadrontherapy advanced example

• Design iteration
      – How to model more efficiently the geometry of the
        beam line

• Code review

Susanna Guatelli
• The project of the hadrontherapy Geant4 simulation
  is important for
      – Precise dosimetry for hadrontherapy
      – Geant4 Physics validation

• Comparison of the CATANA Bragg peak
  experimental measurements with simulation results
      – Validation of alternative Geant4 e.m. and hadronic physics
      – Talk on Monday

Susanna Guatelli

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