Iodine-131: optimal therapy for hyperthyroidism in children and adolescents?

To assess the medium- to long-term effects of I-131 therapy of hyperthyroidism in children and adolescents, we studied 51 patients (age range 6--18; boys, 43 girls) treated with I-131 for Graves' disease with hyperthyroidism at the University of Michigan Medical Center (1951--1972). Patients received total doses ranging from 3 to 81.6 mCi. The mean followup period was 14.6 +/- 7.9 yr. Hyperthyroidism was effectively treated in 49 within 1 to 12 mo. One patient failed to respond to three treatment doses, and hyperthyroidism recurred in two patients: 2 and 11 yr after initial therapy. Of these three patients, two were treated by thyroidectomy and one was retreated successfully with I-131. There were no cases of thyroid cancer, other malignancies or leukemia. The patients' reproductive histories and the health of their offspring were as in the general population. At the time of study, the prevalence of hypothyroidism was 92%, with no recurrent goiters or thyroid nodules. Iodine-131 is found to be safe and effective treatment of hyperthyroidism in children and adolescents and should be the preferred mode of therapy.