Outcome of Fixed and Uncalculated Dose of Radioiodine in the Treatment of Hyper Functioning Thyroid Nodules

Introduction: This is a prospective study of patients treated for a solitary toxic nodule with a fixed dose of radioiodine ( I) and followed for at least 1 year in Mashhad, north east of Iran. 131 Methods: We evaluated 780 patients who presented to the university hospital of Ghaem during a 7-year period because they had at least one thyroid nodule. We found hot thyroid nodules in 95 (12%) patients. Of these patients, 86 (90.5%) were female and 9 (9.5%) were male. Sixty-nine (72.6%) of the patients had thyrotoxicosis and 26 (27.4%) were euthyroid. We treated 49 thyrotoxic patients with I and followed them for a minimum of 12 months. 131 The I dose for all patients was 15 mCi. The patients underwent thyroid function testing before treatment, at 131 6 months after treatment, and, thereafter, once every year. Results: The single fix dose (15 mCi) of radioiodine was sufficient to control hyperthyroidism in most patients (46/49, 93.8%) in 6 months. Because of persistent hyperthyroidism 6 months after the first dose, 3 patients (6.2%) required a second dose. Conclusion: A cure rate of 93.8% can occur within 6 months with a fixed and uncalculated dose of radioiodine. This result is similar to the results of treatment with calculated dose of radioiodine.