Antitumor effect of carboplatin combined with radiation on tumors in mice.

The antitumor effect of cis-diammine-1, 1-cyclobutane dicarboxylate platinum(II) (CBDCA, Carboplatin) and radiation on Ehrlich ascites tumors was evaluated in CD-I mice. A single dose of CBDCA was combined with a single dose of radiation. The antitumor effect was evaluated by tumor volume. Inhibition of tumor growth by the combination of CBDCA and radiation was greater than by CBDCA and radiation alone. The most effective condition was the simultaneous combination of CBDCA with radiation. Further, we examined the radiation influence on the concentration of platinum in tumor tissue. We found that when CBDCA was administered after irradiation, the concentration of platinum in tumor tissue decreased proportionally with time.