Gonadal radiation dose and its genetic significance in radioiodine therapy of hyperthyroidism.

Published estimates of radiation dose to the gonads from 131I therapy of Graves' disease vary widely, largely because of differences in assumptions regarding the details of iodine kinetics. The calculations described in this paper show that hyperthyroid patients treated with 10 mCi of 131I will usually receive a total radiation dose to the ovaries or testes of less than 3 rad. Several common roentgenographic diagnostic procedures may involve a greater radiation dose and a greater genetic hazard than does the usual 131I treatment for hyperthyroidism. It is important to minimize total exposure to radiation, but it seems unreasonable to deny 131I treatment for hyperthyroidism to young men and nonpregnant young women on the grounds of genetic hazard alone.