How I can calculate and plot the spread out Bragg Peak, or SOBP in Geant4?

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1

Hi.
I am working on simulating an ion beam in the water phantom. I need to plot spread out Bragg Peak (SOBP) for my project. But unfortunately, I do not know what should I do.
I would be grateful for any help or suggestion on this issue.
Thank you

2

Dear,

You can calculate and plot the spread out Bragg Peak using the advanced example “hadrontherapy” in Geant4.

best wishes,
Batmunkh.

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3

Dear Batmunkh,

I looked at the hadrontherapy documentation and I was still confused about how to generate SOBP.

Can you tell me how to operate in detail and get the SOBP I need? (260MeV/u 6cmSOBP)

Looking forward to your reply.

your sincerely,
Yuri

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4

Dear Yuri,
You can execute modulatorMacro.mac file in batch mode from hadrontherapy/macro.

Best regards,
Batmunkh.

5

Hi, m.rajabnejad. You can: (1) simulate different monoenergetic bemas with a fixed energy step and record the IDD for each beam; (2)
Optimize the weight of each beam using an optimization algorithm. Remember that in (1), the range or Bragg peak of the selected monoenergetic beam should be within the SOBP

6

Hi yangshiyan

I’m interested in what you’re talking about in terms of optimization algorithms.
What do you mean by an optimization algorithm?

your sincerely
Yuri

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7

Hi batmunkh,

Thank you for your reply. I have now mastered the method of using matRad to broaden the Bragg peak.

I just started using Geant4 this week, so I’m not very familiar with the compilation operation.

Compiling modulatorMacro.mac into an executable is a bit difficult for me, but I’ll try.

Do you have any executable files for my reference?Looking forward to your reply.

your sincerely
Yuri

8

Hi. Thanks for your reply.
what is IDD? How we can write an optimization algorithm?
Can you explain it more precisely?

9

In my work, I generate SOBP with the below Equation:
DSOBP (z)=∑wi×Di (z)
Here DSOBP(z) is the SOBP dose at depth z, wi is the weight of the ith beamlet and Di(z) is the dose contribution of the ith beamlet at depth z
In my work, the MATLAB built-in function lsqnonlin() was applied to solve the beam weights wi， which uses a nonlinear least-squares minimization scheme based on the Trust-Region-Reflective algorithm.

10

IDD means integral depth dose