[Gate-users] How to simulate Lu-176 in LSO crystal

[Bryan McIntosh]

Hi Albert,

Ashok's code looks very similar to what I had sent, and it only uses the
confine command, NOT attach. The whole idea behind the way that I
implemented this method for simulating a Lu-176 ion source was to make the
source large enough to fill the entire scanner volume, then confine the
activity to the crystal only; again, I have not tested it under a newer
version of GATE to verify that it still works, and it may not.

Again, be advised that this does increase the simulation time by a
significant amount since you're adding an ion source that has a lot of beta
and gamma interactions inside the crystal volume; if you can simulate the
noise due to background Lu-176 using the "noise" modules as Emilie and
Maxime suggested earlier, I highly recommend doing that instead. I know
that computers have significantly faster single-thread performance than in
2010 and 2011, but the fewer particles that need to be simulated the better!

Best regards,

-Bryan McIntosh

On Thu, Jun 11, 2020 at 6:20 PM Albert Grace Lieu <albertnew2018 at gmail.com>
wrote:

> Hi Bryan,
>
> Thank you very much for your paper and help. I tried your code for a
> couple of times, it does not confine/attach Lu176 to the crystal. Instead,
> there is only one source showed up at the center of the world. Also, your
> code does not look like confining a source to crystals, because of the
> shape and size of the source. It is much larger than any possible detector
> crystal. My problem now is that I can only attach Lu176 to only one
> crystal, not all of them. Could you please give me any further help,
> please?
>
> Thanks a lot.
> Zhengzhi
>
> On Thu, Jun 11, 2020 at 3:02 PM Bryan McIntosh <mcintoshster at gmail.com>
> wrote:
>
>> Hello Zhengzhi,
>>
>> I wrote the second paper that you linked, and it looks like your initial
>> idea was in the right direction; I made a Lu-176 source that encompassed
>> the entire detector. The difference is that I used the "confine" command
>> for the source, not "attach;" the complete code was as follows:
>>
>> #Single intrinsic source; confined to crystal
>> /gate/source/addSource intrinsic
>> /gate/source/intrinsic/gps/particle ion
>> /gate/source/intrinsic/gps/ion 71 176 0 0
>> /gate/source/intrinsic/gps/monoenergy 0. keV #Super important!
>> /gate/source/intrinsic/gps/angtype iso
>> /gate/source/intrinsic/gps/type Volume
>> /gate/source/intrinsic/gps/shape Cylinder
>> /gate/source/intrinsic/gps/radius 14.5 cm
>> /gate/source/intrinsic/gps/halfz 70.1 mm
>> /gate/source/intrinsic/setActivity 20192.56 Bq
>> /gate/source/intrinsic/gps/confine crystal_P
>>
>> This worked for a system where the crystal volume was named called
>> "crystal," and was duplicated using a cubic array. Be advised that the
>> activity and dimensions of the source were set up to match the Siemens
>> Inveon dPET system; adjust the size and activity accordingly for your
>> particular system. I used an activity of 276 Bq/cm^3 of LSO crystal,
>> calculated from a 2.6% concentration of Lu-176 in the Lu atoms making up
>> the crystal. This is different than the 250 Bq/cm^3 that is often used,
>> since that number was from a measurement that was 250 counts per
>> second/cm^3, not necessarily Bq.
>>
>> This code worked when I ran it back in 2011; I haven't tested it on a
>> GATE version newer than 6.2. I THINK it will work with newer versions of
>> GATE, but your results may vary!
>>
>> Good luck!
>>
>> -Bryan McIntosh
>>
>> On Thu, Jun 11, 2020 at 1:37 PM <
>> gate-users-request at lists.opengatecollaboration.org> wrote:
>>
>>> ------------------------------
>>>
>>> Message: 2
>>> Date: Wed, 10 Jun 2020 22:09:13 -0700
>>> From: Albert Grace Lieu <albertnew2018 at gmail.com>
>>> To: gate-users <gate-users at lists.opengatecollaboration.org>
>>> Cc: Peter Olcott <polcott at reflexion.com>
>>> Subject: [Gate-users] How to simulate Lu-176 in LSO crystal
>>> Message-ID:
>>>         <CAGLxnT-Qdh-NZ8KoBOQuH=
>>> zszHP+zw5f_aeD5ADLNDP9zYzG6Q at mail.gmail.com>
>>> Content-Type: text/plain; charset="utf-8"
>>>
>>> Dear Gate users and developers,
>>>
>>> There are a couple of papers [1
>>> <https://aapm.onlinelibrary.wiley.com/doi/abs/10.1118/1.4824694>,2
>>> <https://ieeexplore.ieee.org/document/5751205>] addressing the
>>> importance
>>> of adding the simulation of Lu-176 in Lutetium based crystal in GATE
>>> simulation. I try to do this to my simulated PET system that has
>>> thousands
>>> of pieces of crystals (created with linear and cubic array repeater). My
>>> general idea of implementing this is to create a Lu176 ion source and
>>> then
>>> attach it to my crystals. However,  when I do:
>>>
>>> /gate/source/Lu176/attachTo Crystal
>>>
>>> the Lu176 is only attached to a single piece of crystal (which can be
>>> visualized with /gate/source/Lu176/visualize 1000 red 3).  Has anyone
>>> implemented this before? Could you please share your thoughts?
>>>
>>> Thanks a lot. Greatly appreciated.
>>>
>>> Zhengzhi
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