[Role of immunologic activity of host in radiotherapy].

The results of our studies on immunologic activity of host following irradiation to tumor in mice were summarized in this paper. The spleen cells from tumor irradiated mice inhibited growth of tumor in mice inoculated tumor cells with these spleen cells. These spleen cells also inhibited the colony formation and tumor growth in vitro system. The cytostatic activity of these spleen cells were enhanced after tumor irradiation. These results suggest that the specific anti-tumor cell-mediated immunity in host is enhanced by local irradiation to tumor, and that these immunologic effects depend on the presence of both T cells and macrophages.