Carcinoma of the oral tongue and floor of mouth: fifteen years' experience with linear acceleration therapy.

One hundred fourteen patients with carcinoma of the oral tongue and floor of mouth were treated with high-dose megavoltage radiation at Stanford University from 1956 to1970. Actuarial 5-year survival for 56 patients with oral tongue lesions was: T', 73; T', 37%; and T', 19%. Similarly, for 58 patients with lesions of the floor mouth, 5-year survival was: T', 73%; T', 37%; and T', 25%. Local control of the primary was obtained in oral tongue T' lesions 10 of 11 times; T', 5 of 8; and T', 13 of 36 times. For floor of mouth, local control was: T', 22 of 26;T', 7 of 14; andT', 3 of 15. There was an indication that better control was obtained if interstitialtherapy was a planned part of the treatment. Dose for local control when external radiation alone was utilized was usually over 1900 rets. Patients with initially clinicallynegative nodes (TXNO) who had a low radiation dose to primary echelon lymph nodes developed later cervical lymph node metastases 38% of the time. In no case did late metastatic disease appear in patients whose necks were treated prophylactically.