[The suppression test in the control of the course of antithyroid drug therapy: renaissance of an in vivo nuclear medicine procedure?].

Measurements of thyroidal suppressibility by thyroid hormones belong to the diagnostic program in nuclear medicine for more than 30 years. Suppression tests are used in follow-up of antithyroidal treatment to predict remission or relapse of hyperthyroidism. Recently, the number of publications dealing with suppression tests has been increasing. Apparently, non-suppressibility of the thyroid after antithyroidal treatment for about 1 year corresponds to a rate of relapse of about 70% whereas in the case of a positive suppression test, the relapse rate amounts to about 20% only. The diagnostic procedures described in the literature are different with respect to radiopharmaceuticals, activity doses, thyroid hormone suppression and, above all, to the time of uptake measurements. After a critical discussion of the literature, a modern diagnostic procedure for the suppression test is proposed using 123I or 99mTc and a computer-assisted gamma camera.