Ergebnisse der Radiojodtherapie der manifesten Hyperthyreose und der autonomen Struma mit Euthyreose

Abstract

In 200 patients follow-up examinations were performed up to one year after radioiodine therapy (RITh) with individual dose calculation. The mean applied dose was significantly lower in patients with immunogenic hyperthyroidism (Graves’ disease) as compared to patients with non-immunogenic hyperthyroidism (disseminated/multifocal autonomy, HYDA). In Graves’ disease the rate of recurrent hyperthyroidism was significantly higher and that of posttreatment hypothyroidism lower. Considering the high recurrence rate in Graves’ disease a higher dose, e. g. 150 Gy, seems to be appropriate. In patients with HYDA who received antithyroid drugs during RITh, recurrence of hyperthyroidism appeared slightly more, and posttreatment hypothyroidism slightly less, frequent. The efficiency of RITh was not significantly reduced by additional treatment with antithyroid drugs. Posttreatment hypothyroidism in patients with euthyroid goiter and disseminated/multifocal autonomy (EUDA) occurred significantly more frequent if the basal TSH level was ≥0.5 µlE/ml before therapy. The goiter size was reduced independent of the basal TSH level. In this group protection by thyroxine could avoid posttreatment hypothyroidism without impairing the reduction of goiter. In HYDA patients after thyroid surgery recurrence appeared less, and in those with EUDA posttreatment hypothyroidism significantly more, frequent. A lower dose seems to be suitable in patients who underwent thyroid surgery before. In patients with focal autonomy after RITh no recurrence of hyperthyroidism was observed. In 9% a suppressed basal TSH level indicating persistent autonomy was seen. Posttreatment hypothyroidism in focal autonomy appeared only in patients without manifest hyperthyroidism before RITh and was significantly more frequent in this group as compared to the other groups of patients. In patients with focal autonomy who developed hypothyroidism the dose calculation was based on a significantly higher volume of the adenoma. In 3 cases cystic parts of the adenoma were not subtracted. This caused a higher radiation dose to the paranodular tissue, which might have been one reason for the high rate of posttreatment hypothyroidism in this group of patients.