Iodine-131 therapy of hyperthyroidism in pediatric patients.

UNLABELLED: The purpose of this retrospective study was to evaluate the utility of 131I as therapy for hyperthyroidism in children and to evaluate its short-term side effects.
METHODS: The results of 131I therapy of hyperthyroidism were evaluated in a group of 35 pediatric patients.
RESULTS: In 29 patients propylthiouracil or methimazole therapy was abandoned due to noncompliance (13), relapse or failure to control hyperthyroidism (13), vasculitis (1), neutropenia (1) or a lupus-like syndrome (1). Average treatment activity was 7.7 +/- 2.9 (s.d.) mCi, corresponding to 0.16 +/- 0.03 mCi/g. Thirty patients (86%) received a single radioiodine treatment and five (14%) were retreated. In patients who became hypothyroid after a single dose, hypothyroidism was noted within 100 days of treatment. Clinical management problems included vomiting in four patients and enuresis in four patients. Mild radiation thyroiditis occurred in one patient and nodularity was noted after therapy in two patients.
CONCLUSION: Iodine-131 is effective for both initial treatment of hyperthyroidism and the treatment of medical treatment failures in pediatric patients. Awareness of vomiting and enuresis as potential management problems is crucial when using 131I in this age group. Therefore, special treatment precautions may be required.