Abstract
During the 23 years between 1962 and 1984, 343 cases received radiotherapy for previously untreated squamous cell carcinoma of the tongue in the National Cancer Center Hospital. The three-year local control rate was 82.0% and the five-year survival rate was 64.7%. Of 218 patients followed up more than five years, 27 cases (12.4%) developed second malignancies in the oral cavity and/or oropharynx more than five years after the first radiation therapy. The second malignancies were most frequent from five to ten years after the initial treatment and on the same side of the tongue as the first radiotherapy. Radiation damage was observed in 28 cases (47%) out of 60 cases who had received interstitial radiotherapy between 1978 and 1984 and had been followed up more than five years. Five cases with sever ulcer and/or osteoradionecrosis required surgery.
