RT Journal Article SR Electronic(1) A1 Darwish, S.M. A1 Ghadban, W.K. A1 Zirie, M.A. A1 Al-Khateeb, D.A.YR 2009 T1 Success Rate of Radioiodine Treatment of Hyperthyroidism in Qatari Patients. JF Qatar Medical Journal, VO 2009 IS 1 OP SP 14 DO https://doi.org/10.5339/qmj.2009.1.14 PB Hamad bin Khalifa University Press (HBKU Press), SN 2227-0426, AB To evaluate the response rate of hyperthyroidism to radioactive iodine treatment (RAI) and the mortality rate post RAI treatment in a Qatari cohort the records were analyzed retrospectively of 113 hyperthyroid Qatari patients (23 male, 90 female) treated with RAI (1-131) in the Endocrine Clinic, Hamad Medical Corporation, between 1984 and2002. 90 (79.6 %) had diffuse goiter, 14 (12.4%) multinodular goiter, 6 (5.3%) single nodular goiter and 3 (2.7 %) unknown etiology. Follow up ranged from two to ten years with free thyroxin and thyroid stimulating hormone being recorded at diagnosis; six months and one year post RAI treatment and yearly thereafter. The incidence of hypothyroidism was 64.4% after six months post RAI treatment and 75.9% at one year. Euthyroid state was high in patients who did not receive antithyroid drugs, whereas the hypothyroid state was higher in a group with pre-treatment antithyroid medication (80% versus 62.8%). The euthyroid state was more in diffuse hyperthyroidism 22.4%, while 84.6% of multinodular goiter became hypothyroid after six months of RAI treatment. Mortality rate was not increased post RAI treatment as compared to general population. Conclusion: The incidence of hypothyroidism was 75.9% at one-year post RAI treatment and the rate of hypothyroidism increased with the length of follow up to 10 years (86.7%). There was no linear relation in response rate to increasing doses of RAI treatment groups., UL https://www.qscience.com/content/journals/10.5339/qmj.2009.1.14