Measurements of total and regional tumor blood flow and organ blood flow using ⁹⁹Tc^m labelled microspheres. An experimental study in rats

Cardiac output, regional tissue and arterial tumor blood flow were studied in rats, with ⁹⁹Tc^m labelled microspheres using a reference sample simultaneously drawn as the spheres were injected. Both cardiac output and regional blood flow can be estimated in absolute values (ml x min^-1 x g^-1). Cardiac output and normal tissue blood flow were not affected by tumor growth in the liver or subcutaneously. In small tumors total blood flow was inversely proportional to tumor size, a finding similar in all 3 tumors studied. A relation found in liver as well as in subcutaneously implanted tumors. Blood flow in subcutaneous tumors was greater than muscle or skin blood flow. Benzpyrene-induced sarcoma had higher blood flow than the hepatoma and the adenocarcinoma. In big tumors the peripheral blood flow was larger than that in the centre of the tumor.