Effectiveness of radioactive iodine (RAI) and its associations with different factors in people presenting with hyperthyroidism

Radioactive iodine (RAI) is the important modality to treat Hyperthyroidism. Successful treatment is determined by development of euthyroidism and / or Hypothyroidism within 6 months of radioactive iodine treatment. The aim of this study was to find out the outcome of RAI treatment and its association with factors like age, gender various etiologies of hyperthyroidism and baseline TSH, FT4 in our population. This retrospective study was conducted at KIRAN from January 2018 to June 2020. A total of 199 participants with complete data were recruited in study after IRB approval. Demographic details, age, gender, the underlying cause of hyperthyroidism Graves' disease, toxic multinodular goiter, toxic nodule, were obtained from medical records along with baseline FT4 & TSH. A fixed dose of 15mci of radioactive iodine was given to all patients and TSH and FT4 were measured at 6 weeks 3, 6, and 12 months. Data was analyzed by SPSS version 20. In our study 77.9 % were females, 22.1 % males, mean age was 41.32 ± 0.99 years, 74.4 % had Graves’ disease, whereas 15 % participants had solitary toxic nodule & toxic multinodular goiter. Post RAI TSH target was achieved earlier compared to FT4. Outcome of RAI treatment in patients with Graves’ disease and toxic nodule revealed statistically significant and early result. Females revealed significant improvement at 6 months in both biochemical markers i-e TSH and FT4 compared to males, however, the FT4 was statistically significant early in elderly participants. Successful treatment was noticed in 75.6 % at 6 &12 months. Fixed dose RAI treatment achieved a 75.6 % success rate at 6 & 12 months, with prompt response noted in female gender, Graves’ disease and toxic nodules. Biochemical (TSH + FT4) improvement was faster in Females, while FT4 normalized earlier in elderly patients and overall TSH levels stabilized before FT4 levels, confirming RAI's effectiveness.