Therapy Dose Calculation in Hyperthyroidism Using the 3-Hour Early I -131 Uptake Measurements

ABSTRACT

Abstract Therapy Dose Calculation in Hyperthyroidism Using the 3-Hour Early I -131 Uptake Measurements   Penpat              Pinyowatanasilp              BSc* Somchai            Uaratanawong                 MD** Division of Nuclear Medicine, Department of Radiology* Department of Medicine** BMA Medical College and Vajira Hospital   Objective: The purpose of this retrospective study was to assess the feasibility of using the radioactive iodine uptake (RAIU) at 3 hours (3RAIN) value in the calculation of   131 I treatment dose in hyperthyroidism patients. Methods: A group of 361 hyperthyroidism patients were randomly divided into two groups (180 and 181 patients) Data from the first group were analyzes to find a mathematical equation describing relationship between the 3RAIU and 24RAIU by linear regression analysis. Similar manner was also performed between 24RAIU and 48RAIU. The predicted 24RAIU and the predicted   131I treatment doses were calculated for the second group of patients based on the relationship equation. Linear regression analysis was also employed to determine statistically significant relationship. Results: The regression relationship equations  were 24RAIU = 32.5 + 0.702 (3RAIU), r = 0.85 (p