Comparison of Clinical Efficacy of Antithyroid Drugs, Radioactive Iodine, and Thyroidectomy for Treatment of Patients with Graves' Disease, Toxic Thyroid Adenoma, and Toxic Multinodular Goiter

Background: The thyroid gland plays an important role in regulating the body's metabolism. On the other hand, primary hyperthyroidism is one of the most common disorders of the endocrine system. Therefore, we aimed to investigate the differences between outcomes of drug therapy with Methimazole & Propylthiouracil (PTU), radioactive Iodine therapy, and surgical procedures as the three most common therapeutic options for primary hyperthyroidism- in patients with Graves' disease, toxic thyroid adenoma, and Toxic Multi Nodular Goiter (TMNG). Methods: This observational study was performed prospectively, and after applying the exclusion criteria, 316 patients with a definite diagnosis of TNMG, toxic adenoma, or Graves' disease, remained in the study. For each patient, one of the therapeutic methods of administration of anti-thyroid drugs, the use of radioactive Iodine, or the use of thyroid surgery was chosen and applied, and during the study period, all patients were followed and evaluated. Results: In this study, 316 patients with primary hyperthyroidism were evaluated, of which 238 (75.31%) patients had Graves' disease, 23 (7.27%) patients had toxic adenoma, and 55 (17.40%) patients had TNMG. The symptoms of thyrotoxicosis syndrome were more common in Graves' disease than in other groups. In this study, 63.82% of drug takers, 20.90% of radioactive Iodine receivers, and 5.26% of patients who had gone under surgery became euthyroid. In addition, 83.27% of drug consumers did not have any side effects. Most patients receiving radioactive Iodine and surgical procedures developed hypothyroidism after treatment, while only 1.70% of those taking anti-thyroid drugs developed this complication. Nevertheless, the failure rate in the drug therapy was highest among all three methods by a percentage of 34.47%. Conclusion: This study suggests a prominent role of drug therapy in the treatment of patients with Graves' disease and TMNG, and in contrast, reduces the role of radioactive Iodine in the treatment of these diseases. However, it is difficult to comment on the treatment of toxic thyroid adenoma based on the findings of this study.