Chulalongkorn Medical Journal


Background: Initial treatment options for Graves’ disease are radioactive iodine (RAI) treatment, antithyroid drugs (ATDs), and surgery. RAI is effective and the definitive treatment for Graves’ disease.

Objective: To evaluate factors associated with success in the first RAI treatment for Graves’ disease.

Methods: A total of 89 patients who received the first RAI treatment for Graves’ disease between September 2016 and January 2021 were retrospectively reviewed. Thyroid function outcome was evaluated within one year after RAI treatment. Logistic regression analysis was performed to identify factors associated with success after RAI treatment.

Results: The success rate of the first RAI treatment was 59.6%, including 15.7% of patients with euthyroidism (14 of 89) and 43.8% of patients with hypothyroidism (39 of 89). All patients were treated with ATDs before RAI treatment. The only factor associated with treatment outcome was the types of ATDs used before RAI treatment (P = 0.016). Logistic regression analysis showed that patients who used both methimazole (MMI) and propylthiouracil (PTU) before RAI treatment were less likely to achieve treatment success as compared to patients who solely used MMI before RAI treatment (odds ratio = 3.554, 95% confidence interval = 1.413 – 8.940, P = 0.007). There was no difference in the influence of MMI and PTU used before RAI treatment on treatment outcome.

Conclusion: The use of both MMI and PTU before RAI treatment reduced the success of the first RAI treatment as compared to solely use of MMI before RAI treatment.





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