Radiation therapy of carcinoma of the oropharynx

From January 1967 through December 1976, 144 patients with carcinoma of the oropharynx were registered at the Department of Radiology, Osaka University Hospital. Forty-two patients were excluded from this study. 102 patients (88 males, 14 females) with previously untreated carcinoma of the oropharynx were treated by radiotherapy alone. Most of the patients were treated with 60Co gamma rays or 6 MV Linear accelerator x-rays. Total tumor dose was decided in every case, depending on the tumor regression and local tolerance. Most of the patients received a total dose of 60 Gy (6,000 rad) or more over 6 to 9 weeks, 7.5 to 10 Gy in 5 fractions per week, except for those with anaplastic carcinoma and in poor general condition. The patients were classified according to the TNM classification of the UICC (1974). Thirty-seven patients were classified into T1, 22 T2, 43 T3; 39 N0, 30 N1, 5 N2 and 28 N3. Five year actuarial survival rates were 42.5, 48.5 and 15.5 per cent in T1, T2 and T3; 41.2, 28.8 and 25.3 per cent in N0, N1 and N2-3, respectively. Most of T1 lesions were successfully controlled with a total dose of 60 - 70 Gy, While T3 lesions were difficult to control with a total dose of 70 Gy or more. Two-thirds of N1 lesions could be also controlled by radiation alone, but N3 lesions were failed to control by radiation alone. Concerning the primary control rate, any difference was not found by site of origin. Radiotherapy of anaplastic carcinoma resulted in higher primary control (83.3%), and survival rate (77.8%) than the one of other histology. There was a high incidence of other primary cancers in our series (19 out of 144 patients). (author)