Outcome of antithyroid medication and radioiodine therapy in pediatric Graves' disease.

Graves' disease is a significant medical condition in children. The optimal therapy is controversial. We reviewed 40 pediatric patients with Graves' disease, 5.0-17.7 yrs of age (mean 10.2 yrs), treated for at least one yr from 1990 to 2002 to assess the outcome of antithyroid medication and radioiodine therapy. The follow-up duration was 1.1-11.8 yrs (mean 5.1 yrs). Clinical variables were also analyzed to identify the prognostic factors. The 40 patients were divided into 3 groups according to their therapeutic options to analyze outcome. To identify predictors, patients who achieved remission after antithyroid drugs within 2 yrs (n = 7) were compared with those who received more than 2 yrs of medication but did not enter remission (n = 25). In group 1, 28 patients received antithyroid drugs for 0.7-10 yrs (mean 3.4 yrs). Fourteen (50%) achieved remission after 0.7-6.6 yrs (mean 2.6 yrs). In group 2, 9 patients received subsequent radioiodine therapy (10-15 mCi) after antithyroid drugs for 1.1-9.2 yrs (mean 4.4 yrs). Remission was achieved after 1-11 months (mean 3.1 months) in 8 (89%). In group 3, initial 131I (12-15 mCi) was used in 3 patients. All of them (100%) attained remission within 2 months. The overall remission rate of patients receiving medical therapy (group 1 and 2) was 38% (14/37). Of the 11 patients who achieved remission after radioiodine, 10 had hypothyroid status and required thyroxine replacement. There were no significant differences with any of the clinical variables that might predict remission after medication within 2 yrs, possibly because of the small number of patients. Our data demonstrate that radioiodine is an efficient and effective therapy for pediatric Graves' disease as first-line treatment or subsequent therapy for those with relapsed disease after medical therapy, although most patients develop hypothyroidism after treatment.