Verification Studies of the Binary Cascade Model of Light Ion Fragmentation Used in GEANT4

1
Verification Studies of the Binary Cascade Model
of Light Ion Fragmentation Used in GEANT4

• I. M. Cornelius1, F. Bourhaleb2, R. Cirio3,
• F. Marchetto3, C. Peroni3

• Centre for Medical Radiation Physics, University
  of Wollongong, Australia
• 2. Fondazione per Adroterapia Oncologica, TERA,
  Italia
• 3. Istituto Nazionale di Fisica Nucleare, Torino,
  Italia

2
Carbon Ion Therapy
3
Carbon Ion Therapy
4
Carbon Ion Therapy
5
Fragmentation in Carbon Ion Therapy

• 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 scatter and ionisation

6
Fragmentation in Carbon Ion Therapy

• Analytical
• Transport equation based on experimental cross
  sections in water
• Implemented at GSI
• Monte Carlo
• Increased interest for treatment planning
  exploiting parallel computing techniques

7
Monte Carlo Codes With Fragmentation

• Several possibilities
• PHITS (JAERI)
• SHIELD-HIT (Karolinska / Russian Acad. Of
  Sciences)
• GEANT4 (4.6.2)
• Binary cascade model of light ion fragmentation
• Hybrid intranuclear cascade - QMD
• Need for verification w. beams and targets
  relevant to therapy
• Goal To use GEANT4 to simulate light ion
  fragmentation experiments for the purpose of
  verification

8
Methods

• Comparisons
• Physical beam model used in treatment planning
  (GSI)
• Energy deposition w. depth for carbon beams in
  water
• Extensively validated with experimental data
• Schall et al 1996 (GSI)
• Fragmentation of light ion beams in water
• Yield of fragments (Z gt 4) with depth
• Gunzert-Marx et al 2003 (GSI)
• Fragmentation of a carbon beam in water
• Spectroscopy of light fragments (A lt 4)

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1. Results
50 MeV/u
100 MeV/u
150 MeV/u
200 MeV/u
250 MeV/u
300 MeV/u
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1. Results Discussion
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Methods

• Comparisons
• Physical beam model used in treatment planning
  (GSI)
• Extensively validated with experimental data in
  water
• Energy deposition w. depth for carbon beams in
  water
• Schall et al 1996 (GSI)
• Fragmentation of light ion beams in water
• Yield of fragments (Z gt 4) with depth
• Gunzert-Marx et al 2003 (GSI)
• Fragmentation of a carbon beam in water
• Spectroscopy of light fragments (A lt 4)

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2. Geometry
DE detector
Target
1o beam diagnostics
H2O t0-25 cm
Ionisation Chambers 90 Ar, 10 CH4, 1 atm t50cm
670 MeV/u
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2. Results C12
46
14
2. Results N14
76
48.0
43.7
18.4
48.5
17.4
58
15
2. Results O16
72
45
62
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Methods

• Comparisons
• Physical beam model used in treatment planning
  (GSI)
• Extensively validated with experimental data in
  water
• Energy deposition w. depth for carbon beams in
  water
• Schall et al 1996 (GSI)
• Fragmentation of light ion beams in water
• Yield of fragments (Z gt 4) with depth
• Gunzert-Marx et al 2003 (GSI)
• Fragmentation of a carbon beam in water
• Spectroscopy of light fragments (A lt 4)

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3. Geometry
DE-E detector
Target
3m
C12 200 MeV/u
BaF2 t14.5cm
NE102 t9mm
Water t13 cm
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3. Results neutrons
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3. Results protons
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3. Results deuterons
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3. Results tritons
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3. Results helium-3
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3. Results alpha
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Conclusions

• These simulations will be useful for
  benchmarking
• Future releases of the binary cascade model
• Other models of ion fragmentation integrated into
  GEANT4 (QMD model under development)
• Experiments of ion fragmentation in tissue
  substitutes useful for further verification
  studies
• P152 experiment NIRS, Japan
• Chimera experiment INFN, Catania, Italy

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Acknowledgements

• 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