Calculations pertaining to the use of fast (equal to or less than 50-MeV) neutrons in cancer radiotherapy.

Abstract

Calculated results are presented for a variety of neutron spectra incident on a tissue‐equivalent phantom. The neutron spectra considered are those produced by 35‐ and 50‐MeV deuterons in a thick beryllium target and by 67‐MeV protons in a thick lithium target. Results are presented for the absorbed doses, LET spectra, cell‐survival probabilities, OERs, and RBEs as a function of position in the phantom. The cell‐inactivation calculations were carried out using the model of Katz et al. and parameters for T‐1 kidney cells. In the case of incident neutrons from 35‐MeV 2H on Be, experimental and calculated absorbed‐dose data are compared as a function of position in the phantom and are shown to be in good agreement.