Dicom Dose deposition error

Flair
1

Dear fluka experts
As fluka medical application introduced.We are able to simulate beam dose distribution in Dicom Material. To learn this function i build an basic proton beam model as an test example. A mono energetic 3*3cm proton beam placed close to patient surface(Y direction). And inject into patient body,the HU conversion file is head.mat in FLUKA dicom module. According to the bragg peak in proton therapy, the hot dose region should located in the tail region as fig 1 shows.

image
image1388×748 186 KB

However, the head region(where mainly material is air) dose is much higher than tail region which is opposed to physical model as fig 2shows.

f2
f21848×799 187 KB

image
image1386×731 56.7 KB

Would you mind help me fix this error?
Program code is append here.
test.inp (1.3 KB)
test.vxl (896.4 KB)

material.inp (12.1 KB)

3

Hi @liweiguang

your test.vxl is a single slice voxel with a width of 1.5 mm and you are shooting a proton beam 3 \times 3 cm^2. My guess is that your protons after a few steps they exit your thin slice.

Do you have the same behavior when you have the full dicom imported?

4

Dear Vlachoudis
Thanks for your help,the output dose is back to normal when i adjust the beam size.I think the error reason is same as you said.Thank you so much.