Efficacy of radioiodine urinalysis

Little exists in the literature to support the efficacy of urinalysis for demonstrating thyroid uptake of radioiodine. A review was made of a variety of kinetic models. Computer analysis and graphics were used to assess the variables in the two models chosen for this study. The applicability of each model was tested by using data obtained from a group of euthyroid subjects. The results indicate that using an integral urine-sampling method and a three-component model yields minimum detectable thyroid uptakes which fall well below required reporting limits. Furthermore, the results show that integral urine samples obtained in the first few hours post exposure may be used to predict major thyroid uptakes in time for effective thyroid blocking.