TY - JOUR T1 - A prospective comparative study of two methods for the individual calculation of 131I activity in the treatment of hyperthyroidism JO - Endocrinología, Diabetes y Nutrición (English ed.) T2 - AU - Pena Pardo,Francisco José AU - López Serrano,Rafael AU - García Cases,Francisco Javier AU - Redal Peña,María Carmen AU - Crespo-Jara,Aurora AU - García Vicente,Ana María AU - Martínez-Almagro Andreo,Andrés SN - 25300180 M3 - 10.1016/j.endien.2020.02.004 DO - 10.1016/j.endien.2020.02.004 UR - https://www.elsevier.es/en-revista-endocrinologia-diabetes-nutricion-english-ed--413-articulo-a-prospective-comparative-study-two-S2530018020301359 AB - ObjectiveRadioiodine (131I) is an established modality of definitive treatment of hyperthyroidism. In spite of the vast experience available, there are still several aspects to be clarified, such as whether fixed or calculated doses should be used. The aim of this study was to assess whether efficacy of this treatment could be improved by implementing a simple dosimetric calculation method including ultrasonographic estimation of thyroid volume and a single measurement of 24-h 131I thyroid uptake. MethodsA prospective non-inferiority study was designed to compare two procedures to calculate radioiodine activity: the “semi-fixed” dose method (A), and the “calculated” dose method (B). The first consisted of activity escalation (185MBq steps) based on etiology of hyperthyroidism, 131I uptake, and treatment objective. The second method was based on the “dosimetric compromise” concept, considering 24-h uptake and thyroid volume as the only factors and using a standard half-life of 5.5 days. The target absorbed dose was 150Gy, but after a preliminary analysis (first 100 cases) it was increased to 200Gy in diffuse toxic goiters (DTGs). ResultsA total of 212 patients were included. Method B was at least as effective in terms of final and functional outcome, with a trend to more success and less hypothyroidism. In addition, activities administered were significantly lower. ConclusionIn radioiodine therapy of hyperthyroidism, a simple dosimetric method that provided results at least equal to those of a fixed dose-based method, with lower administered activities, could be implemented. ER -