[Gate-users] S-values simulation
Maria Inês Ribeiro
mid.ribeiro at campus.fct.unl.pt
Wed Feb 10 17:30:37 CET 2021
Hello 陈戈飞 and Ashok,
I tried my best to implement your suggestions (thank you sooo much). I
found reasonable s-values comparing to the one indicates at medphys.it
For example, my center voxel s-value is of 4.5 mGy/(MBq s) and theirs is 3
mGy/(MBq s).
However, 2 things seem a bit strange:
1) when I load the dose map at MATLAB, I get a lot of zeros in the border
voxels of my kernel. I am using a 11x11x11 kernel, each with 2,21 mm. This
is not supposed to be happening.
2) The values are a bit different from the reference values. Do you know if
the source should have any additional spectrums that I should worry about?
anyway if I add more spectrums, the dose will only increase, which is not
good....
A simulates my source as follows:
/gate/source/addSource Y90Source
/gate/source/Y90Source/setActivity 1 MBq
/gate/source/Y90Source/gps/particle e-
/gate/source/Y90Source/gps/energytype Arb
/gate/source/Y90Source/gps/hist/type arb
/gate/source/Y90Source/gps/hist/point 0.0571 0.0426
/gate/source/Y90Source/gps/hist/point 0.1713 0.0518
/gate/source/Y90Source/gps/hist/point 0.2855 0.0594
/gate/source/Y90Source/gps/hist/point 0.3997 0.0649
/gate/source/Y90Source/gps/hist/point 0.5139 0.0686
/gate/source/Y90Source/gps/hist/point 0.6281 0.0708
/gate/source/Y90Source/gps/hist/point 0.7423 0.0717
/gate/source/Y90Source/gps/hist/point 0.8565 0.0715
/gate/source/Y90Source/gps/hist/point 0.9707 0.0704
/gate/source/Y90Source/gps/hist/point 1.0849 0.0685
/gate/source/Y90Source/gps/hist/point 1.1991 0.0657
/gate/source/Y90Source/gps/hist/point 1.3133 0.0619
/gate/source/Y90Source/gps/hist/point 1.4275 0.0569
/gate/source/Y90Source/gps/hist/point 1.5417 0.0507
/gate/source/Y90Source/gps/hist/point 1.6559 0.0430
/gate/source/Y90Source/gps/hist/point 1.7701 0.0342
/gate/source/Y90Source/gps/hist/point 1.8843 0.0246
/gate/source/Y90Source/gps/hist/point 1.9985 0.0150
/gate/source/Y90Source/gps/hist/point 2.1127 0.00643
/gate/source/Y90Source/gps/hist/point 2.2269 0.00113
/gate/source/Y90Source/gps/hist/inter Lin
/gate/source/Y90Source/gps/pos/type Point
/gate/source/Y90Source/gps/angtype iso
/gate/source/Y90Source/setForcedUnstableFlag true
/gate/source/Y90Source/setForcedHalfLife 230760. s
Thank you so much for your help again!
Maria
Ashok Tiwari <tiwarias at yahoo.com> escreveu no dia terça, 9/02/2021 à(s)
16:49:
> Hi Maria,
>
> You could start a simulation by setting a total number of primaries
> instead of time. Based on my experience with GATEv8.1, the transport of 20
> million particles was found to provide sufficient statistical precision.
> See details in: The Impact of Tissue Type and Density on Dose Point
> Kernels for Patient-Specific Voxel-Wise Dosimetry: A Monte Carlo
> Investigation | Radiation Research | Allen Press
> <https://meridian.allenpress.com/radiation-research/article-abstract/193/6/531/436368/The-Impact-of-Tissue-Type-and-Density-on-Dose?redirectedFrom=fulltext>
>
> The Impact of Tissue Type and Density on Dose Point Kernels for Patient-...
>
>
> <https://meridian.allenpress.com/radiation-research/article-abstract/193/6/531/436368/The-Impact-of-Tissue-Type-and-Density-on-Dose?redirectedFrom=fulltext>
>
> Also, I recommend using ~1 keV energy cuts in dose point kernel
> simulations. Cuts can be set by using:
>
> /gate/physics/Gamma/SetCutInRegion world ... mm
> /gate/physics/Electron/SetCutInRegion world ... mm
>
> /gate/physics/Gamma/SetCutInRegion my_phantom ... mm
> /gate/physics/Electron/SetCutInRegion my_phantom .. mm
>
> Another important thing is an steplimiter, you could set it by using:
>
> /gate/physics/SetMaxStepSizeInRegion my_phantom ... mm
> /gate/physics/ActivateStepLimiter e-
>
> All other infos are described in the paper.
>
> Regards,
> Ashok
>
> On Tuesday, 9 February 2021, 09:19:23 am GMT-6, Maria Inês Ribeiro <
> mid.ribeiro at campus.fct.unl.pt> wrote:
>
>
> Thank you so much.
>
> It was supposed to be 100000 s. I just killed the simulation because it
> was taking too long.
> I swapped to the normal ion source definition since fastY90 can't be used
> for dosimetry.
>
> Do you recommend decreasing cut energy for photons and electrons?
>
> Kind regards,
> Maria
>
> 陈戈飞 <xiaofeizaina at 126.com> escreveu no dia terça, 9/02/2021 à(s) 15:13:
>
> Hi maria
> The total time of your simulations is 10000s，right? If so, you only need
> to multiply by 1000(Gy->mGy) and divide 10000(time to 1s).
> And I recommend setting cut energy for beta and photon. Default is 10 mm.
> You'd better recheck the definition of fastY90. It can't be used for dose
> purposes.
> Thank you
>
>
> 陈戈飞
> 邮箱：xiaofeizaina at 126.com
>
> <https://maas.mail.163.com/dashi-web-extend/html/proSignature.html?iconUrl=https%3A%2F%2Fmail-online.nosdn.127.net%2Fqiyelogo%2FdefaultAvatar.png&name=%E9%99%88%E6%88%88%E9%A3%9E&uid=example%40163.com&ftlId=3&items=%5B%22%E9%82%AE%E7%AE%B1%EF%BC%9Axiaofeizaina%40126.com%22%5D>
>
> 签名由 网易邮箱大师 <https://mail.163.com/dashi/dlpro.html?from=mail88> 定制
> On 02/09/2021 22:38, Maria Inês Ribeiro <mid.ribeiro at campus.fct.unl.pt>
> wrote:
>
> Hi everyone,
>
> I am attempting to compute a dose point kernel in soft tissue for a point
> source of Y90. I am using the fastY90 with an activity of 1 MBq.
> I then ran 40.000 slices of 1 second and stored the dose.
>
> My question is how do I convert my dose map (Gy) into the s values
> (mGy/(MBq.s)) for each voxel?
>
> Here is my could in case it could help to support my question:
>
>
> #===============================================================================
> # GEOMETRY
>
> #===============================================================================
>
> /gate/geometry/setMaterialDatabase data/GateMaterials.db
>
> #WORLD ======================================
> /gate/world/setMaterial Air
> /gate/world/geometry/setXLength 50 mm
> /gate/world/geometry/setYLength 50 mm
> /gate/world/geometry/setZLength 50 mm
>
> #LIVER ======================================
> /gate/world/daughters/name liverPhantom
> /gate/world/daughters/insert box
> /gate/liverPhantom/setMaterial Liver
> /gate/liverPhantom/geometry/setXLength 24.31 mm
> /gate/liverPhantom/geometry/setYLength 24.31 mm
> /gate/liverPhantom/geometry/setZLength 24.31 mm
>
>
> #===============================================================================
> # PHYSICS
>
> #===============================================================================
>
> /gate/physics/addPhysicsList emstandard_opt3
>
>
> #===============================================================================
> # DETECTORS
>
> #===============================================================================
>
> #DOSE ACTOR ==============================
> #builds 3D images of:
> # - the energy deposited (edep in MeV)
> # - dose deposited (Gy)
> # - the number of hits in a volume
>
> /gate/actor/addActor DoseActor VSV
> /gate/actor/VSV/attachTo liverPhantom
> /gate/actor/VSV/stepHitType random
> /gate/actor/VSV/setSize 24.31 24.31 24.31 mm
> /gate/actor/VSV/setPosition 0 0 0 cm
> /gate/actor/VSV/setResolution 11 11 11
> /gate/actor/VSV/enableEdep true
> /gate/actor/VSV/enableUncertaintyEdep true
> /gate/actor/VSV/enableSquaredEdep true
> /gate/actor/VSV/enableDose true
> /gate/actor/VSV/enableUncertaintyDose true
> /gate/actor/VSV/enableSquaredDose true
> /gate/actor/VSV/enableNumberOfHits true
> /gate/actor/VSV/save output/VSV.mhd
>
> #SIMULATION STATISTIC =====================
> #this actos counts the number of steps, tracks, events, runs in the
> simulation
>
> /gate/actor/addActor
> SimulationStatisticActor stat
> /gate/actor/stat/save output/stat-VSV.txt
> /gate/actor/stat/saveEveryNSeconds 60
>
>
>
> #===============================================================================
> # INITIALISATION
>
> #===============================================================================
>
> /gate/run/initialize
>
> /gate/random/setEngineName MersenneTwister
> /gate/random/setEngineSeed auto
>
> #===========================================================
> # SOURCE
> #===========================================================
>
> # fastY90
> /gate/source/addSource y90 fastY90
> /gate/source/y90/setActivity 1. MBq
>
> #=====================================================
> # START
> #=====================================================
>
> /gate/application/setTimeSlice 1. s
> /gate/application/setTimeStart 0. s
> /gate/application/setTimeStop 1000000. s
>
> /gate/application/start
>
>
> Thanks a lot for your attention,
>
> Maria Inês
>
>
>
>
>
> _______________________________________________
> Gate-users mailing list
> Gate-users at lists.opengatecollaboration.org
> http://lists.opengatecollaboration.org/mailman/listinfo/gate-users
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.opengatecollaboration.org/pipermail/gate-users/attachments/20210210/a6ba4104/attachment-0001.html>
More information about the Gate-users
mailing list