The Use of "Figure of Merit" for Collimators

Abstract

Correspondence 6000 rad given in 30 treatments. the total doses to the gonads were, therefore: 2.2 to 2.5 rad (mean 2.6 rad) to the ovaries, and 1.6 to 2.1 rad (mean 1-9 rad) to the testes.It is interesting t o compare these results with the gonad doses from a similar treatment with 200 iiv x-rays. Koren, Alaudal, Flstby and Berteig (1967) made such measurements with a 12 x 15 cm field to the thorax and 200 rad per treatment with the following results: ovary dose. 65 mrad, testis dose, 36 mrad. The complete course of treatment with 200 kv x-rays can seldom exceed 3600 rad in 18 treatments, giving total gonad doses of 1.2 rad to the ovaries, and 0.6 rad to the testes.Thus, contrary to common belief. the gonad dose during radiotherapy treatment to the chest from a 31 Mev betatron is at least comparable with, and may well be greater than the gonad dose received in similar treatment from 200 kv x-raj-s. This work was carried out under Contract No. AT (30-1)-3361 with U.S. AEC.