Intra-arterial mitomycin C treatment of unresectable liver tumours. Preliminary results on the effect of degradable starch microspheres.

Regional chemotherapy might be more efficient if the cytostatic drug is injected together with degradable starch microspheres (DSM), which induce temporary blockage of arterioles and trap the co-injected drug in tumour. Eighteen patients with non-resectable liver cancer were included. Mitomycin C (15 mg/m2) was injected intra-arterially mixed with 900 mg of DSM every six weeks. For estimation of the effect of DSM in the liver a radiolabelled tracer was injected via the same route. Its passage through the liver to the systemic circulation was continuously measured by a detector situated over peripheral blood vessels. The effect of DSM on the tracer passage varied considerably between different patients. The study also indicated opening of new vascular pathways some minutes after the initial injection. The dose of DSM for total blockage of the arterial blood flow, indicated by angiography, also varied. In some patients 540 mg induced total occlusion. In others neither angiographic nor tracer passage were affected by the microspheres although 900 mg (or even more) were injected. Factors such as size of the vascular bed, portal and arterial blood flow and arterio-venous shunting seemed to be of great importance and should be controlled in order to optimize the use of DSM in conjunction with chemotherapy of liver tumours.