[Gate-users] Positron range simulation - inconsistency between GATE 8.0/ 9.0 and between source types

Fri Dec 4 14:43:55 CET 2020

Hi David,

Thanks for your message. I have just tried emstandard_opt4.
I also have previously tried all the different physics lists builder
mentioned in the GATE documentation. Still, the obtained position range is
shorter than expected.

emstandard
emstandard_opt1
emstandard_opt2
emstandard_opt3
emlivermore
emlivermore_polar
empenelope

Following your advice, I opened an issue on Github:
https://github.com/OpenGATE/Gate/issues/379.
There, I have more details and also the macro that I use for simulation.
Hopefully, you can look at it in the monthly meeting.

Thank you.
Kind regards,
Minh

On Fri, Dec 4, 2020 at 7:42 AM David Sarrut <david.sarrut at gmail.com> wrote:

> Hello,
>>
>> maybe just an idea: can you try with
>> /gate/physics/addPhysicsList emstandard_opt4
>> instead of emstandard
>>
>> thanks
>> David
>>
>
>
>
>>
>> On Tue, Nov 17, 2020 at 8:29 AM David Sarrut <
>> David.Sarrut at creatis.insa-lyon.fr> wrote:
>>
>>> Hi !
>>>
>>> thanks for reporting on that. Could you please add a summary of your
>>> findings as an issued in the github, please? (you can copy parts of the
>>> emails of course). It helps us a lot to keep track and correct issues.
>>>
>>> We run a monthly meeting to discuss issues, maintenance and new
>>> features. Hopefully, someone will look at this soon.
>>>
>>> Note also, that we will probably start a new (open) action, in the
>>> following month, dedicated to radionuclide therapy simulations. Your report
>>> will be very helpful.
>>>
>>> thanks again for reporting,
>>> David
>>>
>>> On Tue, Nov 10, 2020 at 12:49 PM Minh Phuong Nguyen <mipbkhn at gmail.com>
>>> wrote:
>>>
>>>> Hi Cassandra,
>>>>
>>>> Thank you for your reply. I use the following standard definition for
>>>> the physics list. I also put the definition of the I-124 point source below.
>>>> How do you set the energy cuts? Do you mean the production threshold:
>>>> https://opengate.readthedocs.io/en/latest/cut_and_variance_reduction_technics.html?highlight=range%20cut#production-threshold
>>>>
>>>> #  P H Y S I C S
>>>> /gate/physics/addPhysicsList emstandard
>>>> /gate/physics/addProcess RadioactiveDecay
>>>> /gate/physics/processList Enabled
>>>> /gate/physics/processList Initialized
>>>>
>>>> # S O U R C E:  I-124
>>>> /gate/source/addSource pointsource
>>>> /gate/source/pointsource/gps/particle ion
>>>> /gate/source/pointsource/gps/ion 53 124 0 0
>>>> /gate/source/pointsource/gps/monoenergy 0. keV
>>>> /gate/source/pointsource/gps/angtype iso
>>>> /gate/source/pointsource/gps/mintheta 0 deg
>>>> /gate/source/pointsource/gps/maxtheta 180 deg
>>>> /gate/source/pointsource/gps/minphi -180 deg
>>>> /gate/source/pointsource/gps/maxphi 180 deg
>>>> /gate/source/pointsource/gps/centre 0 0 0 mm
>>>> /gate/source/pointsource/setActivity 30000000 Bq
>>>>
>>>> Best,
>>>> Minh
>>>>
>>>> On Mon, Nov 9, 2020 at 11:21 PM Cassandra Miller <
>>>> cassandramiller at phas.ubc.ca> wrote:
>>>>
>>>>> Hi Minh,
>>>>>
>>>>> I don't have a solution to your problem, but is it possible that your
>>>>> energy cuts are too high and hence your positrons are stopping too
>>>>> early
>>>>> and depositing all of their energy? Also, what physics list are you
>>>>> using?
>>>>>
>>>>> Best,
>>>>> Cassandra
>>>>>
>>>>> On 2020-11-09 07:27, Minh Phuong Nguyen wrote:
>>>>> > Can anyone help me with this?
>>>>> >  The inconsistency in the positron range simulation with GATE appears
>>>>> > to be an existing problem.
>>>>> > Several related posts in the gate-user archive have not received a
>>>>> > final answer either.
>>>>> >
>>>>> > Minh
>>>>> >
>>>>> > On Thu, Nov 5, 2020 at 10:29 AM Minh Phuong Nguyen <
>>>>> mipbkhn at gmail.com>
>>>>> > wrote:
>>>>> >
>>>>> >> Dear GATErs,
>>>>> >>
>>>>> >> I simulated positron ranges for several isotopes such as F-18 and
>>>>> >> I-124 with GATE. The setup was very simple with a point source at
>>>>> >> the centre of a water environment (20-cm-radius sphere). The sphere
>>>>> >> was that large to make sure that the positrons do not escape the
>>>>> >> water volume.
>>>>> >>
>>>>> >> The obtained mean/max positron range from this simulation was
>>>>> >> shorter than what I found in literature. Then I tested with
>>>>> >> different GATE versions (8.0/ 9.0 with corresponding GEANT4 versions
>>>>> >> as stated in the GATE documentation), and different ways of defining
>>>>> >> the source (ion, e+, fastI124). I observed that the positron range
>>>>> >> result was not consistent when changing these parameters (attached
>>>>> >> figures).
>>>>> >>
>>>>> >> Looking at the range distributions (attached figures), GATE 8.0 with
>>>>> >> ion source produced a lot of annihilations near the decay locations
>>>>> >> (range ~ 0 mm). This was not the case with GATE 9.0 and e+ or
>>>>> >> fastI124 sources.
>>>>> >>
>>>>> >> Does anybody know:
>>>>> >> - why positron range from GATE is shorter than in literature?
>>>>> >>
>>>>> >> - which changes in the new GATE version makes the discrepancy in
>>>>> >> positron range simulation result?
>>>>> >> - what makes the difference in positron range between the ion source
>>>>> >> and other type sources?
>>>>> >>
>>>>> >> Thank you.
>>>>> >> Kind regards,
>>>>> >> Minh Phuong Nguyen
>>>>> > _______________________________________________
>>>>> > Gate-users mailing list
>>>>> > Gate-users at lists.opengatecollaboration.org
>>>>> > http://lists.opengatecollaboration.org/mailman/listinfo/gate-users
>>>>>
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>>>
>>>
>>>
>>> --
>>> David Sarrut, Phd
>>> Directeur de recherche CNRS
>>> CREATIS, UMR CNRS 5220, Inserm U1206
>>> Centre de lutte contre le cancer Léon Bérard
>>> 28 rue Laënnec, 69373 Lyon cedex 08
>>> Tel : 04 78 78 51 51 / 06 74 72 05 42
>>> http://www.creatis.insa-lyon.fr/~dsarrut
>>> _________________________________
>>>  "2 + 2 = 5,  for extremely large values of 2"
>>> _________________________________
>>>
>>
>>
>> --
>> David Sarrut, Phd
>> Directeur de recherche CNRS
>> CREATIS, UMR CNRS 5220, Inserm U1206
>> Centre de lutte contre le cancer Léon Bérard
>> 28 rue Laënnec, 69373 Lyon cedex 08
>> Tel : 04 78 78 51 51 / 06 74 72 05 42
>> http://www.creatis.insa-lyon.fr/~dsarrut
>> _________________________________
>>  "2 + 2 = 5,  for extremely large values of 2"
>> _________________________________
>>
>
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