A clinical study in thyroid uptake rate of I-131 by intravenous administration

Kim, J H; Lee, M J; Yoo, H J; Suh, W H

Abstract

The thyroid uptake study of 131I that has been most commonly used in the diagnosis of the thyroid disease, isusually performed by giving oral administration in fasting state. Therefore, the patients with thyroid diseasehave to visit the hospital in fasting state and on two sucessive days for this uptake study of the thyroid gland.This study was included the total number of 87 cases: Of these, radioiodine was orally administered to 8 healthyindividuals, 46 cases that were euthyroid received it intravenously, and 33 patients with hyperthyroidism, it wasalso administered intravenously. All of the cases, uptake rates by thyroid gland were measured at the time of 15min, 30min, 1,2,6 and 24 hours after administration of 131I. In an attempt to minimize such as inconvenience forthe patients as well as shorten the time of examination, the authors have made an observation on early uptakerates by tyroid gland and changes of thyroid function as related to the meals. The result obtained are summerizedas follow ; 1. In both cases of oral and I.V. administration, there were found higher tendencies of uptake rate innon-fasting state than in fasting state, oral administration stastically showed definite significance ofincreasing uptake rate in non-fasting state after 6 hours while I.V. administration showed this after one hour. 2.When 131I was administered intravenously the early thyroid uptake rate showed higher tendencies than oraladministration, that is, if the values of uptake rate surpass 20% after one hour measurement, hyperthyroidismcould be highly suspected and if exceeds 40% of 6 hour uptake rate, hyperthyroidism may certainly be predicted toexist. 3. The uptake rate of non-fasting state is somewhat higher than in fasting state, however, since thedifferences exist only with the negligerble boundary, the test of non-fasting state is considered to have a goodvalidity. 4. Finally, it was felt that euthyroidism and hyperthyroidism coule be differentiated within 6 hoursafter intravenous injection in an usual non-fasting state, and results not only in an increase in rapidity of thediagnosis but also more convenience with a great saving in time.