An autoradiography study of postoperatively labelled thyroid tissue and iodine storage.

Samples of fresh thyroid tissue obtained from 15 patients undergoing thyroid surgery were incubated with iodine 125 in culture solution to which thyroid-stimulating hormone (TSH) had been added and then examined by autoradiography. The radioactivity registered actively during the 90-min incubation period was primarily found in the lumina of follicles. Even morphologically similar follicles showed very heterogeneous uptake of radioiodine; small follicles often contained the highest concentrations of activity. The method applied appears to be particularly useful for answering the question as to whether and to what extent individual papillary or follicular thyroid carcinomas are able to store radioiodine. This information obtained immediately after surgery may contribute towards establishing the patient's prognosis and help in deciding on postoperative therapy and follow-up. Because of the heterogeneity of radioiodine uptake, it is mandatory to examine a representative sample of carcinoma tissue in order to obtain well-established results.