RADIATION-INDUCED TUMORS OF THE HEAD AND NECK

In order to study the induction of malignancy in normal tissues due to ionizing radiation, we reviewed the files of 2500 patients with a tum our of the head and neck treated at the Netherlands Cancer Institute ( Antoni van Leeuwenhoek Ziekenhuis), Amsterdam, from 1977 to 1993. We t hen checked whether or not these patients had been previously irradiat ed. Patients with a thyroid carcinoma or skin cancer were excluded fro m the study, since it is generally known that previous irradiation is a risk factor in these tumours. Eighteen patients were found to have a malignancy within a previously irradiated area (0.70 per cent). The m ean interval between radiation and diagnosis of the head and neck tumo ur was 36.5 years. There were five soft tissue sarcomas, nine squamous cell carcinomas and four salivary gland tumours. Fourteen patients we re operated upon whereas four received palliative treatment only. The median survival of the total group was 3.5 years. Particularly, in you ng patients because of the better cancer therapy and prolonged surviva l one must be aware of the increased risk of radiation-induced tumours .