X-ray energy optimization in minibeam radiation therapy

The purpose of this work is to assess which energy in minibeam radiation therapy provides the best compromise between the deposited dose in the tumor and the sparing of the healthy tissues.

Monte Carlo simulations (PENELOPE 2006) have been used as a method to calculate the ratio of the peak-to-valley doses (PVDR) in the healthy tissues and in the tumor for different beam energies. The maximization of the ratio of PVDR in the healthy tissues and in the tumor has been used as a criterion.

The main result of this work is that, for the parameters being used in preclinical trials (minibeam sizes of 600 microm and 1200 microm center-to-center separation), the optimum beam energy is 375 keV.

The conclusion is that this is the energy of minibeams that should be used in the preclinical studies.