Radioiodine Therapy Outcome in Patients with Hyperthyroidism in A Tertiary Care Centre

*Clinical Associate, Department of Nuclear Medicine and PET, Bombay Hospital and Medical Research Centre, 12, Marine Lines, Mumbai 400 020. Abstract The purpose of the retrospective study was to assess the outcome of radioiodine therapy in patients treated for thyrotoxicosis. Material and Methods : The medical records of 64 patients (age between 23 and 56 years). These hyperthyroid patients were treated with radioiodine and we have one year follow-up in these patients. Parameters for analysis included the age, sex, clinical symptoms, type of hyperthyroidism, anti-thyroid medications received by the subjects, doses of radioiodine therapy given and the outcome of the therapy after one year. Results : Of all the patients 80% of them were females. The most common cause of hyperthyroidism was Graves' disease (77%) followed by toxic single and/or multinodular goitres (23%). All patients were pre-treated with carbimazole for variable duration. The patients were treated with fixed dose of 131-Iodine toxic therapy with mean administered dose of radioiodine was 8.0 ± 0.5 mCi. Effective control of hyperthyroidism with a single dose of radioiodine was achieved in 40 (62.14%) patients, while 24 (37.86%) required second dose and none required more than two doses during the 1 year follow-up. There were no early side effects. Frequency of hypothyroidism within one year of radioiodine therapy was 65.5% in patients with Graves' disease and 40% in those with multinodular goitres, while patients with single toxic nodule remained euthyroid. Conclusion : Radioiodine therapy is a simple cost-effective modality which can be safely used as a first line or second line therapy for treatment of Graves' disease as well as toxic nodular goitres. However since hypothyroidism is a common sequel of radioiodine therapy, all patients must be closely monitored for the development of this disorder.