[Gate-users] MU and bad_alloc

[Hermann Fuchs]

Hello

The conversion should be internationally regulated. Unfortunately it
seems standards differ across continents. In Europe the IAEA TRS-398
should apply.

As I will soon be entering that field as well, can you keep me informed
on your progress/solution?

Cheers,
Hermann

On Wed, 2011-06-15 at 08:08 +0200, Loic Grevillot wrote:
> Hi,
> 
> I do not have precise reference on it, as it was based on a discussion with
> a manufacturer, but you might find it in medical physics books.
> 
> But the conversion it quite simple:
> A MU is defined as a number of nC collected in the Ionization Chamber (IC),
> which is filled with air.
> SP corresponds to proton stopping power in air and it is based on a fit from
> ICRU data.
> K is a constant which depends on the mean energy loss (W) to create an
> electron/hole pair.
> PTP are the temperature and pression corrections.
> 
> Using all these parameters correctly allows for MU to absolute number of
> protons conversion.
> As all factors are constant except SP, in GATE you can currently get a
> number of protons which is proportional to the absolute number of protons.
> 
> It is always interesting to know who is using GATE and for which purpose.
> Could you describe a bit more?
> 
> Best Regards,
> 
> Loïc Grevillot, Ph.D. Student
> PARTNER project, CERN
> 
> IBA Particle Therapy / Creatis-LRMN
> Tel (IBA):         +32 10 487 729
> 
> 
> 
> 2011/6/14 catarina veiga <catarinavveiga at gmail.com>
> 
> > Thanks for the answer. It was very useful.
> > From what I see on the .cc you have a function that reads the beam MU and
> > energy and converts to number of protons. Can you indicate me any reference
> > to the equation used, like any article were I can find information of it?
> > Kind regards,
> > Catarina Veiga
> >
> >
> > On Tue, Jun 14, 2011 at 10:18 AM, Loic Grevillot <loic.grevillot at gmail.com
> > > wrote:
> >
> >> Dear Catarina,
> >>
> >> I think you should move to Gate V6.1, with Geant4.9.4, because many bugs
> >> should be corrected.
> >> For pencil beams (of protons, but also with any particle you like), 2 new
> >> sources have been added:
> >> - "GateSourcePencilBeam" to define a single pencil beam
> >> - "GateSourceTPSPencilBeam" to define a pencil beam treatment plan
> >> Details are available in the documentation, in the bottom of this page:
> >> http://wiki.opengatecollaboration.org/index.php/Users_Guide_V6.1:Source
> >> You should try also examples "Novice_4" and "Novice_5" from
> >> "examples/example_Radiotherapy" directory.
> >> MU are converted into proton number based on proton stopping power in air
> >> (see "GateSourceTPSPencilBeam.cc") .
> >>
> >> Hope this help!
> >>
> >> Loïc Grevillot, Ph.D. Student
> >> PARTNER project, CERN
> >>
> >> IBA Particle Therapy / Creatis-LRMN
> >> Tel (IBA):         +32 10 487 729
> >>
> >>
> >>
> >> 2011/6/13 catarina veiga <catarinavveiga at gmail.com>
> >>
> >>> Dear users,
> >>>
> >>> I am trying to use GATE on my personal computer to acquire dose deposited
> >>> in
> >>> a proton treatment plan. I need some good accuracy in my calculations,
> >>> but
> >>> for some of my simulations I keep having the simulation aborting, with
> >>> the
> >>> error std bad_alloc. I did some research and understand that this is
> >>> related
> >>> with memory problems. Is there any way to overcome this kind of issues,
> >>> without having to reduce the number of events?
> >>>
> >>> Also, I use GATE V5 to do my simulations. I read that on new version V6
> >>> there are some improvements in definition of a TPS pencil beam source. In
> >>> particular, I am interested in how the conversion of MU to number of
> >>> particles has been developped (for protons). Can you inform me of the
> >>> name
> >>> of the files that have the C++ for this so I can take a look at the code?
> >>>
> >>> Kind regards,
> >>> Catarina Veiga
> >>> _______________________________________________
> >>> Gate-users mailing list
> >>> Gate-users at lists.opengatecollaboration.org
> >>> http://lists.opengatecollaboration.org/mailman/listinfo/gate-users
> >>>
> >>
> >>
> >
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> 

-- 
-------------
DI Hermann Fuchs
Div. Medical Radiation Physics
Department of Radiotherapy
Med. Univ. Vienna / AKH Vienna
Währinger Gürtel 18-20
A-1090 Wien

Tel.  + 43 / 1 / 40 400 7271
Mail. hermann.fuchs at meduniwien.ac.at