Radioactive Iodine for the Treatment of Graves Disease in Paediatric Age: The Experience of a Tertiary Centre and Literature Review

Introduction: Graves' disease affects individuals in paediatric age of all ages and recent epidemiological data point to an increase in its incidence. These data highlight the importance of knowing and differentiating the diverse therapeutic options available. Radioactive iodine (RAI) - in the present context, we refer specifically to iodine-131 (I131) has demonstrated its efficacy in the treatment of hyperthyroidism for more than 70 years. It is commonly used as a second line drug, after failure of anti-thyroid drugs. In this study, the authors describe the experience with RAI in the treatment of children with Graves' disease in a single Portuguese Paediatric centre. Methods: Retrospective analysis of all cases of children with Graves' disease who were treated with RAI. The goal of treatment was the achievement of hypothyroidism after which, therapy with levothyroxine would be started. The activity of RAI was estimated individually according to RAI glandular uptake at 24 hours and functional thyroid parenchymal mass. Results: Seven patients with Graves' disease, who relapsed after adequate treatment with anti-thyroid drugs, were treated with RAI. They were all female, with ages ranging from 12.7 to 16.3 years at first treatment (median; inter-quartile range; 13.9; 13.5-15.1 years). Patients received an activity between 203.5 and 555 MBq (5,5-15 mCi), with a median of 370 MBq (10 mCi). Hypothyroidism was achieved after a median period of 6 months. Two patients needed an additional RAI treatment. becoming hypothyroid 1 month later. This results correspond to an efficacy of 71.4% and 100%, after one or two treatments, respectively (85.7% globally). There were no side effects. Conclusion: RAI was a safe and effective option for the definitive treatment of hyperthyroidism in paediatric Graves' disease.