CHARCOAL LABELING OF MAMMARY-TUMORS IN MICE PRIOR TO CHEMOTHERAPY ANDSURGERY

We have developed a charcoal suspension for marking human breast tumor s prior to chemotherapy and surgery, in order to guide the surgeon dur ing surgical removal of the residual tumor from patients who respond t o treatment. A prechemotherapy/presurgery labeling protocol was develo ped on a model of nude mice bearing grafted mammary tumors, in order t o study the possible effect of a cytostatic drug (cyclophosphamide, Cy ) on tumor-cell labeling by a suspension of micronized charcoal. Intra tumoral injection of the charcoal suspension and that of Indian ink wa s compared in tumors untreated with Cy. Prior injection of micronized charcoal permitted the residual tumor to be detected precisely after t reatment with Cy. There was no diffusion of charcoal particles into th e surrounding tissues, and notable interaction between charcoal and Cy . Indian ink was found to diffuse more within the tumor and at a dista nce from the point of injection than the charcoal suspension.