SALIVARY-GLAND TUMORS AFTER CHILDHOOD RADIATION TREATMENT FOR BENIGN CONDITIONS OF THE HEAD AND NECK - DOSE-RESPONSE RELATIONSHIPS

We have investigated the dose-response relationships for the incidence of salivary gland tumors in a cohort of 2945 individuals who were irr adiated as children between 1939-1962. Most of the patients were treat ed to reduce the size of their tonsils and adenoids. The mean dose to the salivary glands (+/-SD) was 4.2 +/- 1.7 Gy. Eighty-nine patients d eveloped 91 salivary gland neoplasms; 22 had single malignancies, 64 h ad single benign neoplasms, 2 developed two separate benign neoplasms, and 1 developed a single neoplasm but did not have surgery. The major ity (81 of 89) of the patients developed neoplasms in the parotid glan ds. Mucoepidermoid carcinomas were the most common malignancy and mixe d (pleomorphic) adenomas were the most common benign neoplasm. For all salivary gland tumors, the excess relative risk per gray (ERR/Gy) was 0.82; however, the 95% confidence interval was wide (0.04, upper boun d indeterminate). The trend was determined principally by benign tumor s, as there was no dose-response relationship for salivary gland cance r, although there were too few cases to draw definitive conclusions. O verall, our study provides support for an association between salivary gland tumors and radiation exposure, Although most salivary gland tum ors are benign and are usually readily detected, they may cause morbid ity, and people who have been irradiated in the area should be monitor ed for their occurrence. (C) 1998 by Radiation Research Society.