12C fragmentation measurements for hadrontherapy applications

1
12C fragmentation measurements for hadrontherapy
applications

• Introduction
• Status
• French program
• Japanese-French collaboration

2
12C fragmentation in hadrontherapy
Geant4 simulations

• Fragment contribution 20 at the Bragg peak
• G4 precision 10 beyond Bragg peak

• High probability
• Less accurate dose
• Biological effectiveness depends on the particle
  atomic number
• Way of monitoring the energy deposited by PET
  imaging or gamma camera

Accuracy required Bragg peak position 2 mm /
Dose deposited 5
3
Current status of fragmentation studies for
hadrontherapy

• Japan Germany
• Clinical approach validation of the
  analytical codes (TPS)
• 12C depth dose measurements and fragment
  production in water (or PMMA) from 200 to 400
  MeV/u
• only few published data no data for Elt 100
  MeV/u
• For the future French hadrontherapy center
• ? necessity of fragmentation studies
• At which energies ? Elt 100 MeV/u GANIL

4
Fragmentation for hadrontherapy in France

• 2005 Creation of the join research group GDR
  MI2B (IN2P3/CEA)
• medical imagery dosimetry
• Objectives fragment production measurements
  Geant4 physics validation for hadrontherapy
• Clinical approach (water, PMMA)
• Angular distributions, energy spectra of
  fragments
• Comparisons Geant4-experimental data ? necessity
  of physical measurements ?
• fragmentation cross sections on the most
  important elements (C, O, Ca)
• Program accepted by the scientific comity of the
  GDR (April 2006)

5
Experimental set-up

• 12C at 50-90 MeV/u (at 90 MeV/u, the Bragg peak
  is at 2.1 cm of depth)
• on water or PMMA targets with various
  thicknesses
• Detection of charged particles, neutrons and
  gamma rays

• Gamma rays
• (study of dose monitoring)
• Profiles as a function of target depth of
• Prompt gamma rays
• Positron emitter production

6
Schedule
Middle of 2006
2007
2008
experiment
Simulations (charged part. ?)
Detector design
Data-simulation comparison
New experiments ? (Physical approach)
7
The french collaboration

• LPC Caen 4 researchers
• G. Ban, J. Colin, D. Cussol, J.M. Fontbonne, M.
  Labalme
• IPN Lyon 4 researchers, 1 student
• M. Chevallier, D. Dauvergne, A. Demeyer, P.
  Lautesse, C. Ray, M.C. Ricol, E. Testa
• IPHC Strasbourg 3 researchers, 1 student
• F. Hass, V. Rauch, M. Rousseau, M. D. Salsac

8
Japanese-French collaboration
9
Carbon fragmentation in nuclear emulsion

• 4? tracking detector
• (spatial resolution of 1 µm)
• Detection and identification of charged particles

density of grains along the path

• Saturation for multiple charge (3?Z)
• ? RD for charge identification (3?Z?6)
• Refreshing method
• Use of CR-39

10
RD of emulsion technology to study fragmentation

• TECHNOLOGY
• RD in progress in the university of Nagoya
  (Prof. Niwa)
• High speed systems developed both in Japan and
  France (IPN Lyon) for a future neutrino
  oscillation experiment
• FIRST RESULTS since 2003
• Fragmentation cross sections at HIMAC (Japan)
• C?Water C ? Lucite interaction for Egt150 MeV/u

11
Japanese-French collaboration

• Fragmentation measurements with emulsion
  technology at HIMAC and GANIL (10 MeV/u - 400
  MeV/u)
• At GANIL
• Complementary French and Japanese detection
  systems
• Emulsion scanning system available in Lyon