Factors Influencing Effect of Radioactive Colloidal Gold on Free Tumor Cells in Peritoneal Fluid.

Abstract

Sarcoma 37 and a malignant lymphoma were cultured as free cells in the peritoneal fluid of mice by serial transfers of these cells. Requisite number of tumor cells were inoculated intraperit. into several groups of mice (S-37 in CFW or dba strain; lymphoma in dba mice only) and treated, after 2 to 14 days, with various doses (0.05 to 0.3 mc) of radioactive colloidal gold, either intraperit. or intraven. In several series of expts. the mice were pre-treated with inactive (decayed) colloidal gold (0.1 or 0.2 cc.) before the treatment with active gold. Control expts. investigated the growth characteristics of S-37 and lymphoma cells in untreated mice, the effect of the treatment with active or inactive gold in normal mice and the effect on tumor cells of radioactive gold stored in macrophages. The expts. have outlined the role of the following factors in production of a radiotherapeutic effect of the radioactive colloidal gold on free tumor cells:[long dash]Strain of the tumor; strain of mice; size of the inoculum; interval between the inoculation and the treatment; route of treatment; dose of radioactivity; and pre-treatment with inactive gold. The effect was estimated by checking on the 6th day after the treatment, the percentage of surviving mice and the presence of tumor cells in the peritoneal fluid. The results were interpreted in the light of the data on growth characteristics of tumor cells and macrophage reaction in the peritoneal fluid.