The therapeutic value of chemotherapeutic agents lies not only in their cytotoxic effectiveness against malignant cells, but equally in the degree normal tissue can tolerate them. The resistance of tumor against these drugs is often quantitative in nature with the tumor seeming completely resistant unless sufficiently high concentrations of the agent reach the tumor. Since the concentration of the cytotoxin that will reach the tumor is dependent on the characteristics of the microcirculation of the tumor and its host, the feasibility of delivering a curative dose of this agent without the danger of toxicity should be apparent from a hemodynamic evaluation of the tumor and surrounding tissues. For this reason, blood flow to the microcirculation of a transplantable tumor implanted in different organs was estimated by the rubidium 86 (86Rb) clearance technique.
Materials and Methods
Adult New Zealand male rabbits, randomly bred and weighing 3 to 5 kg, were