what is the default delivery technique?

[junjunjanna]

hello everyone,
I'm a little confused about the delivery technique for proton and carbon-ion.
when I use the Generic machine data, is that delivered by passive scattering or active scanning during the planning process?

[wahln]

I suggest to read the paper and our Wiki.

matRad is built for intensity modulated planning, and thus the Generic data and the dose calculation algorithms are tuned for scanning. It is possible to include a passive scattering beam through some hacking of how the pencil-beam kernels in the database are convolved with the incoming fluence (if this is known after the passive beam elements).

[junjunjanna]

Thanks for your reply, wahln!
If that is a scanning system, would that be possible to show the position of the Bragg peak of each scanning spot (as image attached below)?

[wahln]

There's unfortunately no built-in function to dipslay that. The spot positions / the spot grid can, however, obtained from the stf within matRad. The lateral positions in the isocenter are stored within stf.ray under the variable rayPos, and each of these "rays" has mutliple energies from which the position in water-equivalent depth can be obtained. From this one could (using the ray-tracing algorithm) calculate each spot position in world coordinates and then display them.

[junjunjanna]

I see, thank you so much, wahln!
Just one more question related, is matRad using any algorithm to optimize the scanning path during particle treatment planning?

[wahln]

There is no dedicated algorithm to optimize the scan path. Would be excited to have one in matRad though, in case you want to develop one ;-)