How to Configure Spot Spacing Parameters in Proton Therapy with matRad

[yydxhhxy]

In matRad, I notice that for proton therapy planning, the following parameters are used to define the spot distribution:

pln.propStf.bixelWidth: Specifies the lateral spot spacing (transverse plane)
pln.propStf.longitudinalSpotSpacing: Specifies the longitudinal spot spacing (beam propagation direction)
My question is:

How should I set these parameters in relation to the actual beam spot size (spotsize) of my proton therapy system?

[qianyujia]

hello, I have also meet this question, how to keep the STF while import, but not to the new stf with the bixelwidth=5; Have you solved the problem? thank you.

[wahln]

How should I set these parameters in relation to the actual beam spot size (spotsize) of my proton therapy system?

There is no direct answer. besides spot-size it also depends on the width of the bragg-peak (dependent on initial energy spectrum), anatomy / complexity of the target / oar structures, desired field complexity etc. Best way is to experiment a bit, starting from 5mm bixel width and 3mm longitudinal spacing.

hello, I have also meet this question, how to keep the STF while import, but not to the new stf with the bixelwidth=5; Have you solved the problem? thank you.

Do you mean during DICOM import? It should keep the settings, but importing a full plan / stf only really makes sense if you have set-up the machine information.