Radioiodine therapy of benign thyroid disorders: functional thyroid autonomy

In the last 15 years, several concepts have been developed to further improve the outcome of radioiodine therapy in functional thyroid autonomy. Results of radioiodine therapy in functional autonomy are considerably better than in Graves' disease. All of the currently-applied concepts offer healing rates of 75-100%, but they differ considerably in the hypothyreosis rates attained. The target volume can be precisely determined by sonography only in unifocal autonomy. In the case of multifocal and disseminated autonomy, the entire thyroid is taken as the target volume and the focal dose is reduced ('dosimetric compromise'). TcTUs-based dose concepts calculate the functionally autonomous volume from the TcTUs and replace the target volume by sonography, in the TcTUs-adapted dose concepts, sonographic target volume is left and the focal dose varied in dependence of the suppression uptake. The objective is to attain a high rate of success with a low rate of hypothyreosis. (orig.)