EFFICACY OF RADIOIODINE THERAPY IN PATIENTS OF PRIMARY HYPERTHYROIDISM USING SINGLE FIXED DOSE OF I-131

Objective: To determine the efficacy of radioiodine in patients with primary hyperthyroidism. Study type: Descriptive study. Settings: Nuclear medicine department of Punjab Institute of Nuclear Medicine, Faisalabad. Study duration: November 2024 to April 2025. Methodology: Patients of both sexes between the ages of 20 and 70 who had hyperthyroidism (TSH < 0.25 mIU/L) who were either intolerant to or did not respond to antithyroid medication were included. Individuals who had a history of RAI or thyroid surgery, were pregnant or nursing, had a big goiter with compressive symptoms, had cardiac or other co-morbidities, or had Grave's opthalmopathy were excluded. All patients were then administered a single, fixed dose of I-131, which was 25 mci for MNG, 20 mci for diffuse toxic goiter, and 29 mci for toxic adenoma. After three months of treatment, patients were monitored, and efficacy was assessed. If any of these conditions were present—hypothyroidism (TSH >5.2 mIU/L, FT3 <1.5 pg/ml, and FT4 <0.8 pg/ml) or euthyroidism (normal TSH level (0.3 to 3.0 mU/L) and normal free T4 level (10-30 nmol/L)). Results: The average age was 51.32 ± 7.61 years. Of the 89 patients, 24 (27.0%) were men and 65 (73.1%) were women, resulting in a male to female ratio of 1:2.7. Mean TSH levels were 0.21 ± 0.17 mIU/L. In this study, 74 (83.15%) patients with primary hyperthyroidism responded well to radioiodine therapy with a single fixed dose of I-131. Conclusion: In conclusion, hyperthyroidism can be effectively treated with radioactive iodine-131 therapy.