ABSTRACT
INTRODUCTION:Radioactive iodine(I131) therapy is an established definitive treatment for Graves' hyperthyroidism.However,the optimal method of determining the radioiodine treatment dose remains controversial.OBJECTIVE: To compare the efficacy of fixed dose versus calculated dose regimen in the treatment of Graves' hyperthyroidism among Filipinos METHODOLOGY: Diagnosed Graves' disease patients underwent thyroid ultrasound to estimate thyroid size. Patients were randomized to either fixed or calculated dose of radioiodine treatment. For fixed dose group,the WHO goiter grading was utilized: Grade 0 (5mCi), Grade 1 (7mCi), Grade2 (10mCi), Grade 3 (15mCi). For calculated dose group the following formula was used: Dose(mCi)= 160uCi/g thyroid x thyroid gland weight in grams x 100 / 24-hour RAIU(%)Thyroid function test (TSH,FT4) was monitored every three months for one year. RESULTS: Of the 60 patients enrolled, 45 (fixed dose; n= 27, calculated dose; n= 18) completed the six months follow-up study. Analysis was done by application of the intention-to-treat principle. The percentage failure rate at third month in the fixed vs. calculated dose group was: 26 v. 28% with a relative risk (RR) value of 0.93. At six months post-therapy, there was a noted reduction in the failure rates for both study groups (11 vs. 22%, respectively), with a further reduction in the relative risk value (0.67), favoring the fixed dose group.CONCLUSION: Fixed dose radioiodine therapy for Graves' disease is observed to have a lower risk of treatment failure (persistent hyperthyroidism) at three and six months post-therapy compared to the calculated dose.
Subject(s)
Humans , Male , Female , Middle Aged , Adult , Iodine Radioisotopes , Iodine , Intention to Treat Analysis , Graves Disease , Hyperthyroidism , Goiter , Thyroid Function Tests , Treatment FailureABSTRACT
BACKGROUND: Clinical manifestations of thyroid dysfunction are variable. The UST Scoring Index for thyroid disorders, formulated in the 1990s to evaluate thyroid functional status, was based on total thyroid hormone levels and thyroidal iodine uptake. However, with the advent of newer and more sensitive tests, the recommendations and practice now dictate the use of thyrotropin (TSH) and free thyroxine (FT4) levels in the confirmation of thyroid dysfunction.OBJECTIVE: To validate the UST Scoring Index for thyroid disorders using TSH and FT4.METHODS/RESULTS: The UST Clinical Scoring Index was administered to 170 patients presenting for thyroid-relatedcomplaints. Thyroid function tests were then requested (TSH and Free T4) and they were classified according to biochemical status. We obtained the following: 43 hyperthyroid, 102 euthyroid and 25 hypothyroid subjects. The mean TSH for the 3 groups were 0.08, 1.28, and 41.50 uIU/mL respectively (NV 0.27-3.75.) Mean FT4 levels were 36.18, 18.33, and 8.43 pM/L respectively (NV 10.3-25.0.) The most frequent findings in the biochemically hyperthyroid group were thyroid enlargement (88%), easy tiredness (74%), palpitations (70%), and nervousness (65%); in the euthyroid group, easy tiredness (62%), thyroid enlargement (54%), palpitations (53%), and irritability (49%); in the hypothyroid group, easy tiredness (64%), exertional dyspnea (52%), weight gain (44%), and constipation (44%.) The UST scoring index for thyroid disorders has a sensitivity of 67%, specificity of 84%, and accuracy rate of 80 %, with AUC of 0.850 on ROC analysis for the detection ofhyperthyroidism. For detecting hypothyroidism, it has a sensitivity of 40%, specificity of 92%, and asccuracy rate of 85%, with AUC 0.7553 on ROC analysis.CONCLUSION: The UST scoring index for thyroid disorders has good sensitivity, specificity and accuracy rate based on ROC when validated using TSH and FT4 for the detection of hyperthyroidism and hypothyroidism.