Combined radiotherapy and Corynebacterium parvum treatment of a murine fibrosarcoma.

A single dose of Corynebacterium parvum (Cp) at 70 microgram, 175 microgram or 350 microgram was effective in suppressing the growth of a subcutaneous fibrosarcoma and occasionally in inducing complete regression and in prolonging the survival time of C3H/HeJ tumor-bearing mice. A single exposure of x rays at 2,000 rads induced some complete regression, but a higher number of complete regressions was induced by combined x-ray and Cp treatment. In the combined x-ray and Cp treatment, Cp given on the same day immediately after x irradiation was best. When 70 microgram of Cp was given a few days before x rays, the intravenous and intraperitoneal routes were better than the intratumor route of injection.