[Gate-users] Problem recreating results from published paper

[Hermann Fuchs]

Hello

I was trying to recreate the results from the recent GATE paper
concerning the validation of a proton beam.

"GATE V6: a major enhancement of the GATE
simulation platform enabling modelling of CT and
radiotherapy",Phys. Med. Biol. 56 (2011) 881–901

In the paper a 150 MeV proton beam directed at a 40x40x40cm water
phantom using the hadrontherapyStandardPhys.mac physics list
and additional StepLimiter of 1 mm and production
thresholds 1 mm range cut for electrons, positrons and photons were
used.
A proton range of 158 mm was determined.

However, using the same setup (and GATE v6.1) I measure only a proton
range of 156 mm, which is quite a discrepancy.
I modified the radiotherapy benchmark included with Gate. I have
attached the script below.
I would be grateful for any suggestion.

Yours,
Hermann Fuchs


#=====================================================
# GEOMETRY
#=====================================================
/gate/geometry/setMaterialDatabase GateMaterials.db

# World
/gate/world/geometry/setXLength 5 m
/gate/world/geometry/setYLength 5 m
/gate/world/geometry/setZLength 5 m
/gate/world/setMaterial Air


# Global Box
/gate/world/daughters/name             mainbox1
/gate/world/daughters/insert           box
/gate/mainbox1/geometry/setXLength 40 cm
/gate/mainbox1/geometry/setYLength 40 cm
/gate/mainbox1/geometry/setZLength 40 cm
/gate/mainbox1/placement/setTranslation 0.0 0.0 20 cm
/gate/mainbox1/setMaterial Water
/gate/mainbox1/vis/setVisible 1
/gate/mainbox1/vis/setColor blue


/gate/geometry/setIonisationPotential Water 75 eV
/gate/geometry/setIonisationPotential Air 85.7 eV


#=====================================================
# PHYSICS
#=====================================================

/control/execute hadrontherapyStandardPhys.mac

/gate/physics/Gamma/SetCutInRegion      world 1 mm
/gate/physics/Electron/SetCutInRegion   world 1 mm
/gate/physics/Positron/SetCutInRegion   world 1 mm

/gate/physics/Gamma/SetCutInRegion      mainbox1 1 mm
/gate/physics/Electron/SetCutInRegion   mainbox1 1 mm
/gate/physics/Positron/SetCutInRegion   mainbox1 1 mm

/gate/physics/SetMaxStepSizeInRegion world 1 mm
/gate/physics/ActivateStepLimiter proton       
/gate/physics/ActivateStepLimiter deuteron     
/gate/physics/ActivateStepLimiter triton       
/gate/physics/ActivateStepLimiter alpha        
/gate/physics/ActivateStepLimiter GenericIon   

/gate/physics/displayCuts


#=====================================================
# MATRIX FOR DOSE MAP OUTPUT
#=====================================================

#Energydeposition along z Axes (Beam direction)
/gate/actor/addActor  DoseActor  enerDepZaxes

/gate/actor/enerDepZaxes/save output/protonWater150MeV-OneDimZ.txt
/gate/actor/enerDepZaxes/attachTo    	   mainbox1
/gate/actor/enerDepZaxes/stepHitType           random
#50 mu resolution in z direction
/gate/actor/enerDepZaxes/setResolution         1 1 8000 
/gate/actor/enerDepZaxes/enableEdep            true
/gate/actor/enerDepZaxes/enableUncertaintyEdep false
/gate/actor/enerDepZaxes/enableDose            false
/gate/actor/enerDepZaxes/enableUncertaintyDose false
/gate/actor/enerDepZaxes/enableNumberOfHits    false


#=====================================================
# INITIALISATION
#=====================================================

/gate/run/initialize
# Enable the following lines to display available and enabled processes
# /gate/physics/processList Available
# /gate/physics/processList Enabled


#=====================================================
# BEAMS
#=====================================================

/gate/source/addSource mybeam gps

/gate/source/mybeam/gps/particle proton
/gate/source/mybeam/gps/pos/type Beam
/gate/source/mybeam/gps/pos/rot1 0 1 0
/gate/source/mybeam/gps/pos/rot2 1 0 0
/gate/source/mybeam/gps/pos/shape Circle
/gate/source/mybeam/gps/pos/centre 0 0 0 mm
/gate/source/mybeam/gps/pos/sigma_x 3 mm
/gate/source/mybeam/gps/pos/sigma_y 3 mm
/gate/source/mybeam/gps/ene/mono 150 MeV
#/gate/source/mybeam/gps/ene/type Gauss
#/gate/source/mybeam/gps/ene/sigma 2.0 MeV
/gate/source/mybeam/gps/direction 0 0 1


#=====================================================
# VISUALISATION
#=====================================================

#/control/execute visu.mac

#=====================================================
# START BEAMS
#=====================================================

# JamesRandom Ranlux64 MersenneTwister
/gate/random/setEngineName MersenneTwister
/gate/random/setEngineSeed 1021

# /gate/random/verbose 1
# /gate/source/verbose 0

/gate/application/noGlobalOutput
/gate/application/setTotalNumberOfPrimaries 1000000
/gate/application/start

exit