Effective dose evaluation for BNCT brain tumor treatment based on voxel phantoms

•For a typical brain tumor BNCT, the effective dose was calculated to be 1.51 Sv.•The average absorbed dose for eye lenses was 1.07 Gy.•The effective doses for both male and female voxel phantoms were calculated.•The effective doses were compared between voxel and mathematical phantoms.

For BNCT treatments, in addition to tumor target doses, non-negligible doses will result in all the remaining organs of the body. This work aims to evaluate the effective dose as well as the average absorbed doses of each of organs of patients with brain tumor treated in the BNCT epithermal neutron beam at THOR. The effective doses were evaluated according to the definitions of ICRP Publications 60 and 103 for the reference male and female computational phantoms developed in ICRP Publication 110 by using the MCNP5 Monte Carlo code with the THOR-Y09 beam source. The effective dose acquired in this work was compared with the results of our previous work calculated for an adult hermaphrodite mathematical phantom. It was found that the effective dose for the female voxel phantom is larger than that for the male voxel phantom by a factor of 1.2–1.5 and the effective dose for the voxel phantom is larger than that for the mathematical phantom by a factor of 1.3–1.6. For a typical brain tumor BNCT, the effective dose was calculated to be 1.51 Sv and the average absorbed dose for eye lenses was 1.07 Gy.