Material index in scoring LET, using GETLET function

[kwlibuaa (Kaiwen Li)]

Dear FLUKA experts,

Scoring both LETd and LETt of primary protons in water

Dear @kwlibuaa, Thank you for your question. First of all, would you mind sharing some of the results that you find incorrect, together with the beam shape dependance? It would be very useful to me in order to pinpoint the differences. Using as a reference this post with the canonical definition of LETt and LETd, it seems to me that your LETt calculation is coherent. However, the way you define LETd is different since dose is used, which is proportional to the deposited energy. You are somehow…

As we have discussed before, it is possible to obtain both LETd and LETt by using the GETLET function, but that was only in a water phantom, where the material index of water is a fix number 26.

ENDLET = GETLET(JTRACK,EKIN,PLA,ZERZER,26)

When I want to score the LET in a CT DICOM file, where the assigned material in each voxel might be different, how could I use the GETLET function with a correct material index?

[msacrist (Mario Sacristan Barbero)]

Dear @kwlibuaa,

Thank you for your question. To use the material of a certain region in the function GETLET you can use the function MEDFLK(MREG,1). It returns the material number as a function of the region number MREG. In this way, the material number is adjusted to each position where the function is evaluated.
I hope this helps.

Regards,
Mario