[Thyroid cancer risk from iodine-131-treatment? (author's transl)]

Six of 240 patients with thyroid carcinoma had a history of 131I treatment for a benign disease. All patients had underwent a total thyroidectomy. In this 2.5% of our cancer patients a tumor induction by radiation might be po-sible. The six cases are described in detail and the literature is revieved. A longer observation period than 30 years will be necessary to exclude an increase in prevalence of thyroid carcinomas after 131I treatment in the adult. The clinical importance of this possible increase will dubious; the thyroid carcinoma prevalence in a nonendemic goitre region has been estimated with 5--6%. On the other hand an increase in development of "benign" thyroid nodules has been seen after 131I treatment of thyrotoxicosis. Therefore not every younger hyperthyroid patient should be treated in this manner.