[Gate-users] Gate dose to water problem

[Luc SIMON]

Dear all and in particular:




*david.sarrut at creatis.insa-lyon.fr
<david.sarrut at creatis.insa-lyon.fr>gergely.patay at gmail.com
<gergely.patay at gmail.com>alexvergaragil at gmail.com
<alexvergaragil at gmail.com>thomas at deschler.fr <thomas at deschler.fr>*

*and all the authors of DoseActor.cc ...*



*Following the mail of Tony Younes we investigated this bug.*

*We found that the NaN values seem to come from DoseToActor.cc at this
level (l 360)*



    // Other particles should be taken into account (Helium etc), but bug ?
FIXME
    if (PartName== "proton" || PartName== "e-" || PartName== "e+" ||
PartName== "deuteron") {

      DEDX = emcalc->ComputeTotalDEDX(Energy, PartName, material, cut);
      DEDX_Water = emcalc->ComputeTotalDEDX(Energy, PartName, "G4_WATER",
cut);

doseToWater=edep/density/Volume/gray*(DEDX_Water/1.)/(DEDX/(density*e_SI));
    }
    else {
      DEDX = emcalc->ComputeTotalDEDX(100, "proton", material, cut);
      DEDX_Water = emcalc->ComputeTotalDEDX(100, "proton", "G4_WATER", cut);

doseToWater=edep/density/Volume/gray*(DEDX_Water/1.)/(DEDX/(density*e_SI));
    }



*In this "if" section sometimes DEDX and DEDX_Water are 0.0 and the
division 0 / 0 is NaN (please note that 3 / 0 is infinite, which is not a
NaN value...)*
This problem is fixed. But now another question : why in the "else" part
DEDX_water is computed for proton ????? (while proton should be considered
in the first part... )


Moreover, photons should not contribute to "dose". So why do we need this
"else" part ????

Thank you for your help.

Luc & Tony









2017-01-31 16:22 GMT+01:00 Grevillot Loic <loic.grevillot at medaustron.at>:

> Hi,
>
> Could you send macros and output files?
>
> Best,
>
> Loïc
>
>
>
>
>
>
>
> *From:* tony youness [mailto:tony_youness at live.com]
> *Sent:* Tuesday, January 31, 2017 3:14 PM
> *To:* Grevillot Loic; gate-users at lists.opengatecollaboration.org
> *Subject:* Re: Gate dose to water problem
>
>
>
> Hi,
>
> I am simulating high energy photon beams (6 and 10 MeV) for external
> radiotherapy applications.
>
> I tried both ("Water" and "G4_WATER") and I am still getting NAN values
> (only when the absorbed dose is reported as absorbed dose to water). The
> voxel values between both absorbed dose report (Dose to medium and Dose to
> water) are also different even though that the medium is WATER.
>
> Regards,
>
> Tony
>
>
>
> On 31/01/17 8:37 am, Grevillot Loic wrote:
>
> Hello,
>
>
>
> Which beam are you simulating? (photons, electrons, light ions, etc.)
>
> Which water did you define in your simulation? “Water” is different from
> “GEANT4_WATER” -> could you try using GEANT4_WATER?
>
>
>
> Best,
>
> Loïc
>
>
>
>
>
>
>
> *From:* Gate-users [mailto:gate-users-bounces at lists.opengatecollaboration.
> org <gate-users-bounces at lists.opengatecollaboration.org>] *On Behalf Of *tony
> youness
> *Sent:* Monday, January 30, 2017 1:04 PM
> *To:* gate-users at lists.opengatecollaboration.org
> *Subject:* [Gate-users] Gate dose to water problem
>
>
>
> Dear All,
>
> I am facing a problem with gate dose actor. When enabling dose to water i
> get Nan values in some of the voxels in the water region of my phantom. I
> also get different values in the water voxels between both dose reports
> (dose to medium and dose to water). It seems like there's a bug when gate
> tries to converts dose to medium into the dose to water *when in the
> water region*. Has anyone already faced this problem? Any help would be
> much appreciated.
>
> Kind Regards,
>
> Tony Younes
>
>
>
>
>
>
>
> *Disclaimer:*
> Please notice our E-Mail Disclaimer http://www.medaustron.at/email-
> disclaimer/
>
>
>
>
>
> *Disclaimer:*
> Please notice our E-Mail Disclaimer http://www.medaustron.at/email-
> disclaimer/
>
>
> _______________________________________________
> Gate-users mailing list
> Gate-users at lists.opengatecollaboration.org
> http://lists.opengatecollaboration.org/mailman/listinfo/gate-users
>



-- 
___________________

SIMON Luc, Physicien Médical, PhD
Département d'Ingénierie et de Physique Médicale - IUCT-Oncopole -
Toulouse, FRANCE
INSERM UMR 1037 (CRCT) - Equipe 15 - Toulouse, FRANCE
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.opengatecollaboration.org/mailman/private/gate-users/attachments/20170202/3f060298/attachment.html>