Tanyaluck ThientunyakitSuchitra ThongmakTeerapon PrempraphaMahidol UniversityPrince of Songkla University2018-09-242018-09-242010-08-01Journal of the Medical Association of Thailand. Vol.93, No.8 (2010), 969-97701252208012522082-s2.0-77956399733https://repository.li.mahidol.ac.th/handle/20.500.14594/29579Objective: To compare the effectiveness of radioiodine therapy with estimated dose and calculated dose in hyperthyroid patients. Material and Method: A prospective randomized study in 144 hyperthyroid patients referred for 131I treatment was performed between June and December 2007. The patients were divided into two groups according to the I dose administered, estimated group using dose based on gland size and calculated group using dose based on both gland size and 24-hour 131I uptake. Outcome assessment was done at 12 months post-treatment. Results: Eleven of 144 patients were excluded due to loss to follow-up and five became euthyroid before 131I treatment. Fifty-six of 128 patients (45.3%) experienced persistent/recurrent hyperthyroidism, 26 (20.3%) developed hypothyroidism, and 44 (34.4%) were euthyroid. Outcome was unrelated to the methods of I-131 dosing. Only gender and goiter size were found to be correlated with the clinical outcomes. Conclusion: An estimated I-131 dosing method using gland size determined by palpation is as effective as calculated method using 131I uptake. This method is more cost effective and brings greater patient convenience.Mahidol UniversityMedicineArticleSCOPUS