[Radioimmuno-assay of TSH before and after TRH in 350 patients with previous resection of euthyroid goiter (author's transl)].

Radioimmuno-Assay (RIA) of Thyroid-Stimulating-Hormone (TSH) was performed before and after i.v.-injection of Thyrotropin-Releasing-Hormone (TRH) in 350 patients subsequent to previous resection of euthyroid goiter to find out the optimal treatment schedule for preventing recurrent goiter. In patients without recurrent goiter the dosis of thyroid hormone was considered to be sufficient, if the difference in TSH-levels before and after TRH (delta-TSH) was equivalent to or less than 10 microunits/ml. In patients with recurrent goiter the optimal suppressive dosis of thyroid hormone was accepted for a delta-TSH less than or equal to 2,5 microunits/ml. 126 out of 135 patients, who were set on an immediate and continuous postoperative treatment were free of goiter, 58 presented a delta-TSH less than or equal to 10 microunits/ml (average interval of treatment = 2,5 years), 68 patients had elevated delta-TSH (average interval of treatment 2,1 years) as a sign of insufficient treatment. In 9 patients recurrent goiter was detected in spite of "adequate" treatment. 41 out of 57 patients, set on delayed and partly continuous, partly discontinuous treatment had recurrent goiter (in average after 10 years). delta-TSH was not indicative. 158 patients without any treatment had borderline or slightly increased delta-TSH (in average after 10 years). 122 of these 158 patients had recurrent goiter, 36 were free of goiter. The results favor the necessity of treatment with thyroid hormones starting immediately after operation and with continuous treatment. The combined use of TSH-RIA and TRH-test reliably informs about the individual thyroid hormone dosis necessary for prevention or treatment of recurrent goiters.