[Gate-users] use of doseactor, voxelized phantom and source to generate dose and edep map

Eng. M Pharaon pharaon_m at hotmail.com
Sun May 31 14:04:36 CEST 2020


Dear Park
It seems that something is weird in the final results or there is something that I didn’t  fully understand in Gate code . me too am not having a good results all the time
I'm facing a problem with dose by region actor and my whole project is depending on solving this problem so I could have accurate results .
When I use this actor on low energies, such as 0.01 Mev , the deposited energy results are good and I could confirm from mhd output file that all the energy has been located in the source origin.
But when I use energies for example from 0.3 to 2 Mev, I get results lower than they should be compared to the same voxel phantom results that has been simulated using mcnp code,
Could that be the same problem you faced?
Below you can check the macrofiles I am using
#/control/execute verbose.mac
#/control/execute ../mac/visu.mac


#==============================
# GEOMETRY
#==============================
/gate/geometry/setMaterialDatabase ../data/GateMaterials.db
#----------------------
# World
#----------------------
/gate/world/geometry/setXLength 300 cm
/gate/world/geometry/setYLength 300 cm
/gate/world/geometry/setZLength 300 cm
/gate/world/setMaterial Air
/gate/world/vis/setVisible 0
# Body
/gate/world/daughters/name phantom
/gate/world/daughters/insert ImageNestedParametrisedVolume
/gate/phantom/geometry/setImage ../data/Segm.mhd
/gate/phantom/geometry/setRangeToMaterialFile ../data/range_geo.dat
#==============================
# PHYSICS
#==============================
#----------------------
# Physics List
#----------------------
/gate/physics/addPhysicsList emlivermore

#----------------------
# Cuts and Step limiters
#----------------------
/gate/physics/Electron/SetCutInRegion world 0.01 mm
/gate/physics/Gamma/SetCutInRegion world 0.01 mm
/gate/physics/Electron/SetCutInRegion phantom 0.001 mm
/gate/physics/Gamma/SetCutInRegion phantom 0.001 mm
/gate/physics/SetMaxStepSizeInRegion phantom 0.001 mm
/gate/physics/ActivateStepLimiter e-
/gate/physics/displayCuts

#########/gate/physics/addPhysicsList                                      emlivermore
#########/gate/physics/Gamma/SetCutInRegion                                world 10.0 mm
##########/gate/physics/Electron/SetCutInRegion                             world 10.0 mm
##########/gate/physics/Positron/SetCutInRegion                             world 10.0 mm
##########/gate/physics/Gamma/SetCutInRegion                                phantom 0.1 mm
##########/gate/physics/Electron/SetCutInRegion                             phantom 0.1 mm
##########/gate/physics/Positron/SetCutInRegion                             phantom 0.1 mm

#==============================
# DETECTORS
#==============================
# It is possible to save a DoseActor as a 3D matrix.
/gate/actor/addActor                                              DoseActor  dose3D
/gate/actor/dose3D/attachTo                                       phantom
/gate/actor/dose3D/stepHitType                                    random
/gate/actor/dose3D/setResolution                                  1346 693 147
/gate/actor/dose3D/enableDose                                     true
/gate/actor/dose3D/save                                           ../output/output.mhd
/gate/actor/dose3D/inputDoseByRegions                             ../data/Segm.mhd
/gate/actor/dose3D/outputDoseByRegions                            ../output/DoseByRegions.txt
#==============================
# INITIALISATION
#==============================
/gate/run/initialize
#==============================
# BEAM
#==============================
# Source
/gate/source/addSource                                            phantom voxel
# DECLARATION THAT THE VOXELIZED SOURCE WILL BE ENTERED USING IMAGE DATA
/gate/source/phantom/reader/insert                              image
/gate/source/phantom/imageReader/translator/insert              range
/gate/source/phantom/imageReader/rangeTranslator/readTable      ../data/ActivityRange.dat
/gate/source/phantom/imageReader/rangeTranslator/describe       1
# THE FOLLOWING LINE ALLOWS YOU TO INSERT THE IMAGE DATA USING THE APPROPRIATE EXTENSION FILE
/gate/source/phantom/imageReader/readFile                       ../data/Segm.mhd
# THE DEFAULT POSITION OF THE VOXELIZED SOURCE IS IN THE 1ST QUARTER
# SO THE VOXELIZED SOURCE HAS TO BE SHIFTED OVER HALF ITS DIMENSION IN THE NEGATIVE DIRECTION ON EACH AXIS
/gate/source/phantom/setPosition                                 -673  -346.5  -73.5 mm

# THE FOLLOWING LINES CHARACTERIZE THE SIZE (NO DIFFERENCE WITH AN ANALYTICAL SOURCE)
/gate/source/phantom/gps/particle gamma
/gate/source/phantom/gps/energytype Mono
/gate/source/phantom/gps/monoenergy 0.1 MeV
/gate/source/phantom/gps/angtype iso
#==============================
#==============================
# START SIMULATION
#==============================
/gate/random/setEngineName MersenneTwister
/gate/random/setEngineSeed auto

/gate/application/setTotalNumberOfPrimaries 1000
/gate/application/start
==============================================================
#activity range file
1
135   135   1
Best Regards
Eng. Pharaon


From: Gate-users <gate-users-bounces at lists.opengatecollaboration.org> On Behalf Of Hyun Soo Park
Sent: Saturday, May 30, 2020 5:43 AM
To: gate-users at lists.opengatecollaboration.org
Subject: [Gate-users] use of doseactor, voxelized phantom and source to generate dose and edep map

Hello, Gate users,

We just have a  relatively simple task of estimating internal radiation dosimetry of 18F-labeled PET tracer using doseactor, voxelized phantom and source. However, me and my colleagues are struggling with this beautiful research tool because of lack of experiences and not enough understandings about it.

We acquired PET/CT images using the radiotracer at varying time points to describe the biodistribution of the tracer. CT images were the voxelized phantom and PET images were the matched voxelized source.

By following to many contributors’ exercices and examples, we’ve finally generated following macro that returns common outputs of internal dosimetry by GATE (i.e., Dose and Edep, etc).

Our questions are obvious:

1) is the following macro defined well to generate Dose and Edep map for given voxelized phantom and source?

2) definition of the fluorine-18 was appropriate?

3) how could we measure dose of a specific organ, such as kidney, using dose map? Could it be done by common VOI analysis measuring voxel mean value?

4) the latest simulation gave us non-sense results of showing continuously increasing dose in a organ, while the radioactivity is apparently decreasing as time. how could it be explained?

Best wishes, and have a great weekend!

Park

#=====================================================
# VEROBOSITY
#=====================================================

/control/execute  mac/verbose.mac

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

/control/execute mac/visu.mac

#=====================================================
# GEOMETRY
#=====================================================

/gate/geometry/setMaterialDatabase                                                    data/GateMaterials.db

# World
/gate/world/geometry/setXLength                                                          10 cm
/gate/world/geometry/setYLength                                                          10 cm
/gate/world/geometry/setZLength                                                          10 cm
/gate/world/setMaterial                                                                                               Air
/gate/world/vis/setVisible                                                                                           1
/gate/world/vis/forceWireframe

# Voxel phantom
/gate/world/daughters/name                      ct
/gate/world/daughters/insert                    ImageRegularParametrisedVolume
/gate/ct/geometry/setRangeToMaterialFile         data/range_geo.dat
/gate/ct/geometry/setImage                   data/ct-gate.mhd
/gate/ct/setSkipEqualMaterials                                                                 1
/gate/ct/vis/setVisible                                                                                   1
# /gate/ct/vis/setColor                                                                                                  blue
/gate/ct/vis/forceWireframe

# /gate/geometry/rebuild

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

/gate/physics/addPhysicsList                                                                                      emstandard_opt3
/gate/physics/addProcess                                                                                                            RadioactiveDecay #to generate decay process of F-18

#=====================================================
# DETECTORS
#=====================================================

/gate/actor/addActor                                DoseActor  doseDistribution
/gate/actor/doseDistribution/attachTo                                                 ct
/gate/actor/doseDistribution/stepHitType            random
/gate/actor/doseDistribution/setSize                30 28.8 99 mm #Size in mm
/gate/actor/doseDistribution/setPosition            0 0 0 cm # Origin
/gate/actor/doseDistribution/setResolution          58 48 165 #Size (pixel)
/gate/actor/doseDistribution/enableEdep             true
/gate/actor/doseDistribution/enableUncertaintyEdep  true
/gate/actor/doseDistribution/enableSquaredEdep      false
/gate/actor/doseDistribution/enableDose             true #from true
/gate/actor/doseDistribution/setDoseAlgorithm                                VolumeWeighting
# /gate/actor/doseDistribution/enableDoseToWater      true #new set
/gate/actor/doseDistribution/enableUncertaintyDose  true #from true
/gate/actor/doseDistribution/enableSquaredDose      false
/gate/actor/doseDistribution/enableNumberOfHits     true
/gate/actor/doseDistribution/save                   output/output.mhd

/gate/actor/addActor                                                                                   SimulationStatisticActor stat
/gate/actor/stat/save                                                                                   output/stat.txt
/gate/actor/stat/saveEveryNSeconds                                                                      60

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

/gate/run/initialize

#=====================================================
# SOURCE :
#=====================================================

#Description

#Ion
/gate/source/addSource                                                                                                                                                                              ion                voxel
/gate/source/ion/reader/insert                                                                                                                                 image
/gate/source/ion/imageReader/translator/insert                                                                              linear
/gate/source/ion/imageReader/linearTranslator/setScale                                             1. Bq
/gate/source/ion/imageReader/readFile                                                                                                               data/pt-gate.mhd
/gate/source/ion/imageReader/verbose                                                                                                               1
/gate/source/ion/setPosition                                                                                                                                     -15.0 -14.4 -49.5 mm

/gate/source/ion/gps/particle                                                                                                                                    ion
/gate/source/ion/gps/ion                                                                                                                                                            9 18 0 0 #F-18
/gate/source/ion/gps/energytype                                                                                                                            Mono
/gate/source/ion/gps/monoenergy                                                                                                                         0. keV
/gate/source/ion/gps/angtype                                                                                                                                   iso
/gate/source/ion/setForcedUnstableFlag                                                                                                              true
/gate/source/ion/useDefaultHalfLife                                                                                                                      6586 s


/gate/source/ion/dump                                                             1

# /gate/source/list

#=====================================================
# RANDOM
#=====================================================
/gate/random/setEngineName MersenneTwister
/gate/random/setEngineSeed auto

#=====================================================
# START
#=====================================================

/gate/application/noGlobalOutput
/vis/enable
/gate/application/setTotalNumberOfPrimaries                                                                   500000 #acceptable uncertainty is at 500000
/gate/application/start

--
연구중점교수, 분당서울대학교병원
전화번호:
(사무실) +82-31-787-2936
(휴대전화) +82-10-8833-2806
팩스: +82-31-787-4018
이메일: hyuns at snu.ac.kr
<mailto:hyuns at snu.ac.kr>

Hyun Soo Park, PhD
--
Research professor
Department of Nuclear Medicine
Seoul National University Bundang Hospital, Seongnam, Korea
Telephone:
(Office) +82-31-787-2936
(Mobile) +82-10-8833-2806
Fax: +82-31-787-4018
email: hyuns at snu.ac.kr<mailto:hyuns at snu.ac.kr>
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