Postoperative irradiation in malignant epithelial tumors of the parotid.

From 1954 through 1979, 77 patients with malignant tumors of the parotid gland were referred from the Department of Head and Neck Surgery for postoperative irradiation. The analysis has been made by grouping the patients according to the estimated amount of disease left after the surgical procedure and by the histological types. There were no local failures in the low-grade tumors, and there were 6 in the 63 patients with high-grade tumors. With gross residual disease or potential residual disease the patients received slightly higher doses than those without. Although there were only 6 failures in the various histological types, there was perhaps a trend to more failures in the adenocarcinomas. There was no difference in the failure rates in patients having had a total resection of the facial nerve or partial resection or no resection. The preferred treatment has been a combination of 20 MeV photons and 18 MeV electrons. Five neck failures were essentially a result of lack of elective irradiation of the neck. Severe complications appeared only in the patients irradiated either for gross residual disease or excision of a recurrence with a high risk of widespread microscopic residual disease.