Radiation effect on carcinoma of the oral cavity treated by a single large dose irradiation

A single large dose irradiation method was performed in 21 cases of carcinoma of the oral cavity in stages T1 and T2. Macroscopically, the tumor disappeared in 16 cases 4 weeks after the irradiation. Microscopic analysis disclosed Ooboshi-Shimosato' Grade IV in 11 out of 16 cases from 4 weeks to 2 months after the irradiation. A relationship between the grade of cell infiltration in the destroyed cancer nests and prognosis was also investigated. The cases which had no mononuclear cell infiltration with local cure or had remarkable cell infiltration showed favorable prognosis. Furthermore, the degree of cell infiltration by the irradiation group was apparently prominent than by operation without radiation group (p<0.05). Peripheral lymphocytes, T cells, B cells and blastoid formation rate induced by PHA in vitro were all increased after the irradiation. The reaction to 4 kinds of immunological skin tests was also enhanced. Especially, PPD skin reaction was enhanced remarkably (p < 0.05). Five years actuarial survival rate and relative survival rate of fresh 17 cases was 88.9% (98.7%) in stage I, 63.5% (73.5%) in stage II. (J.P.N.)