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 (i
ncluding tuberculous lymphadenitis in 39 patients), and malignant tumo
rs in 17 patients (including 9 laryngeal cancers and 5 thyroid cancers
). The radiation-induced cancers included 35 cases of hypopharyngeal c
ancer, 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 su
rgery for their cancer. The clinical course was poor and the outcome e
xtremely poor, especially in those patients with field carcinogenesis.
It is emphasized that excessively high dosage and wide radiation fiel
d should be avoided, and that radiotherapy for young patients with mal
ignancies requires extremely careful management.