Iodine-131 Therapy of Hyperthyroidism

Abstract

The most common causes of hyperthyroidism are Graves' disease and toxic nodular goitre (TNG). There are 3 recognised modalities of treatment for hyperthyroidism. Antithyroid drug therapy, surgery and Iodine-131 (I-131) administration. Antithyroidal drugs are effective in Graves' disease to maintain remission on long term and useful for abating the initial symptoms of hyperthyroidism. Relapses are frequently seen when the medication is discontinued. Surgery, either subtotal or near-total thyroidectomy, has a limited role in the treatment of hyperthyroidism. Approximately for 50 years, I-131 has been succesfully used for the treatment of hyperthyroidism. The use of radioiodine being a first-line therapy for hyperthyroidism is growing, since the modality is well tolerated, effective, non-expensive and easy to perform with the only significant long term sequelae being the risk of developing radioiodine-induced hypothyroidism. This report outlines the methodology and clinical application of radioiodine treatment in hyperthyroidism.