Clinical course of pediatric and adolescent Graves' disease treated with radioactive iodine.

The use of radioactive iodine (RAI) therapy in children and adolescents with Graves' disease is increasing; however, few data exist to guide dosing in this population. We aimed to determine the clinical course, failure rate and factors associated with failure of RAI for pediatric Graves' disease. A retrospective chart review from a tertiary care pediatric endocrinology clinic (1990-2003) identified 22 patients (12.7 +/- 4.0 years at diagnosis) with Graves' disease treated with RAI after initial pharmacological therapy. Patients received a calculated dose of RAI (0.1 mCi/g thyroid tissue, adjusted for 6-h radio-iodine uptake). Twenty-seven percent (95% CI 11-50%) remained hyperthyroid and required a second dose. If the first RAI was successful, the average time to hypothyroidism was 2.96 +/- 1.05 months. There were no statistically significant differences between those successfully treated with one dose and those requiring re-treatment. This high failure rate indicates a need to examine dosing of RAI in this age group.