Outcomes Associated with Treatment of Hyperthyroidism with Radioiodine; A Single Center Retrospective Study

Background:  Hypothyroidism and hyperthyroidism are prevalent conditions with potentially crippling health consequences that globally affect all populations. Hyperthyroidism is overproduction and persistent release of thyroid hormones that can be stratified into a number of subtypes with varying magnitudes and treatment outcomes. Despite of decades of treatment of hyperthyroidism with radioiodine, the success of treatment is still debatable and influenced by many factors.  Objective: To determine outcomes associated with treatment of hyperthyroidism with radioiodine. Methods: All patients screened for thyroid disease at King Abdullah Medical City, Makkah in between 2012-17 were included in the analysis (N = 353). Eighteen questions were used to assess the presence or absence of symptoms associated with hyperthyroidism. 251 out of 353 patients were found eligible for screening with thyroid-stimulating hormone, free triiodothyronine (fT3) and free thyroxin (fT4). On the basis of laboratory analysis, 73 patients were eligible for the differing RAI therapeutic regimens. Treatment outcomes were assessed 6 months after the patients received RAI therapy, at which time they were classified as being hypothyroid, euthyroid, or hyperthyroid. Results: Females were predominantly affected by hyperthyroidism (75.2%) compared with males (24.8%). However, males were significantly more likely than females to have Graves’ ophthalmopathy (p < 0.01), anxiety (p < 0.05), and insomnia (p < 0.05). A total RAI dose of ≤15 mCi was effective in eliminating most hyperthyroidism: ≤12 mCi, 26/29 = 89.7%; 12.1–15 mCi, 28/30 = 93.3%. Using bivariate analysis, the association of treatment effectiveness with each of the symptoms and comorbidities revealed significant correlations only for diabetes mellitus (rho = −0.428, p < 0.001). Conclusions: Our data suggests that radioiodine remains an effective option of treating hyperthyroidism in most of the patients who qualify for it.