[Value of posttherapeutic scintigraphy for the demonstration of distant metastases of differentiated carcinomas of the thyroid gland].

The value of posttherapeutic scintigraphy performed at discharge with the remaining radioactivity after an ablative radio-iodine therapy was studied in 190 patients with differentiated carcinomas of the thyroid gland (54% papillary and 46% follicular carcinomas). 163 patients (86%) had no signs of disease. 33 patients had distant metastases. In six out of them, the examination method allowed a first demonstration of metastases. In seven further cases, additional, hitherto unknown foci were found. There was a specificity of 100% and a sensitivity of 82% (no false positive findings, six false negative findings). Further to the usual image-producing examination methods (native X-ray diagnosis, sonography and CT), posttherapeutic scintigraphy furnishes early information about the formation of distant metastases. Therefore it is helpful to indicate a regional percutaneous X-ray therapy and to assess the prognosis.