[Gate-users] Gate dose to water problem

[Grevillot Loic]

Hello,

Currently the DoseToWater part is incomplete and should contain other particles, e.g. carbon ions, helium, etc.
The else part only means at the moment that if the system encounter another type of particle, it will calculate the dose to water assuming this particle is equivalent to a proton with an energy of 100 MeV.
If we would remove the if (which could also be an option), then the dose to water would be equal to the dose, as it would not be rescaled by the stopping power ratio.

So currently the DoseToWater works for electrons, photons and proton beams as far as I know.
I have in my to do list to upgrade it for particles up to carbon ions, but did not have time yet, that being said it should not be very difficult, just require a bit of time and also to find out the correct naming convention used in Geant4 for the different particles that can be generated.

Hope this help!

Best,
Loïc



From: Manuel Bardiès [mailto:manuel.bardies at inserm.fr]
Sent: Thursday, February 02, 2017 5:27 PM
To: Luc SIMON
Cc: Grevillot Loic; gate-users at lists.opengatecollaboration.org
Subject: Re: [Gate-users] Gate dose to water problem

And thanks to Andreas as well (Luc missed his mail ;-)

Le 2 févr. 2017 à 17:23, Luc SIMON <uhqd75 at gmail.com<mailto:uhqd75 at gmail.com>> a écrit :

Dear all and in particular:
david.sarrut at creatis.insa-lyon.fr<mailto:david.sarrut at creatis.insa-lyon.fr>
gergely.patay at gmail.com<mailto:gergely.patay at gmail.com>
alexvergaragil at gmail.com<mailto:alexvergaragil at gmail.com>
thomas at deschler.fr<mailto:thomas at deschler.fr>
and all the authors of DoseActor.cc<http://doseactor.cc> ...

Following the mail of Tony Younes we investigated this bug.
We found that the NaN values seem to come from DoseToActor.cc<http://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<mailto:loic.grevillot at medaustron.at>>:
Hi,
Could you send macros and output files?
Best,
Loïc



From: tony youness [mailto:tony_youness at live.com<mailto:tony_youness at live.com>]
Sent: Tuesday, January 31, 2017 3:14 PM
To: Grevillot Loic; gate-users at lists.opengatecollaboration.org<mailto: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] On Behalf Of tony youness
Sent: Monday, January 30, 2017 1:04 PM
To: gate-users at lists.opengatecollaboration.org<mailto: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<mailto: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
_______________________________________________
Gate-users mailing list
Gate-users at lists.opengatecollaboration.org<mailto:Gate-users at lists.opengatecollaboration.org>
http://lists.opengatecollaboration.org/mailman/listinfo/gate-users

Disclaimer:
Please notice our E-Mail Disclaimer http://www.medaustron.at/email-disclaimer/

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.opengatecollaboration.org/mailman/private/gate-users/attachments/20170202/07e881e7/attachment-0001.html>