Exclusive radiation therapy: the treatment of early tonsillar tumors.

One hundred and ninety-three T1 or T2 tumors of the tonsillar region have been treated by exclusive external irradiation between 1970 and 1982. Seventy-five percent of these tumors were classified as T2. There was no relationship between T and N stages. The nodal involvement was essentially linked to the macroscopic appearance of the tumor (superficial or nodular) and to the histology. The 5-year survival rate of the whole population was 58%. N stage and macroscopic appearance only influenced the survival. The local control was 88% for T1, 79% for T2. The main prognostic factors for local control were the histological type, with a 93% local control rate for poorly differentiated tumors versus 73% for well differentiated ones, and the macroscopic appearance, with a 83% local control rate for nodular tumors versus 75% for superficial ones. Superficial tumors spreading forward the anterior pilar have a higher local failure rate. All the patients' charts have been reviewed, and we observed a high percentage of marginal recurrences. The technique of irradiation, above all in case of a superficial tumor, must take into account the possibility of "geographic miss" and keep large safety margins.