TREATMENT OF HYPERTHYROIDISM WITH I¹³¹: ONE TO TEN YEARS FOLLOW UP ON 285 CASES

Abstract

For 10 years from 1955 to 1964, 415 cases of hyperthyroidism were treated with I131 and the existing status could be traced in 285 of them. Among these cases, 85.6% were euthyroid, 8.4% hypothyroid, and 6.0% still hyperthyroid. The incidence of hypothyroidism increased relative to the passage of years after treatment. The relatively low incidence of hypothyroidism in this series, compared with the reports from Western countries, is probably due to the relatively low dose of I131 used in each treatment. The high content of iodine in the Japanese diet might have some relationship to this low incidence. No incidence of thyroid tumor or leukemia was observed in these patients. No abnormalities were observed in 41 children born from 27 patients after I¹³¹ treatment.