Radiation-induced cancers of the head and neck region.

A total of 65 patients with radiation-induced cancers of the head and neck region were treated and evaluated. The primary disease for which the radiotherapy had been applied was benign disease in 48 patients (including tuberculous lymphadenitis in 39 patients), and malignant tumors in 17 patients (including 9 laryngeal cancers and 5 thyroid cancers). The radiation-induced cancers included 35 cases of hypopharyngeal cancer, 15 of thyroid cancer, and 13 of cervical esophageal cancer. The mean duration from radiotherapy until the diagnosis of cancer was 12.8 years in the patients with malignant primary tumor and 32.9 years in those with benign primary diseases. Most of the patients underwent surgery for their cancer. The clinical course was poor and the outcome extremely poor, especially in those patients with field carcinogenesis. It is emphasized that excessively high dosage and wide radiation field should be avoided, and that radiotherapy for young patients with malignancies requires extremely careful management.