Regional infusion
chemotherapy delivers higher
drug concentrations to the
tumor than other methods and may decrease systemic
drug levels. We evaluated the efficacy of
degradable starch microspheres (DSMs) to further increase
drug delivery to hepatic
tumors. Rabbits implanted with hepatic Vx-2
tumors were treated with hepatic arterial infusion of
doxorubicin hydrochloride labeled with
carbon 14 with and without DSMs. Tissue levels of
doxorubicin were measured in the heart, liver, and
tumor 30 minutes after
drug infusion. Blood
drug levels, as well as biliary and renal excretion rates of
doxorubicin, were determined. In rabbits receiving the
drug alone,
doxorubicin uptake by the
tumor and liver were 17.1 +/- 12.8 and 55.3 +/- 9.5 nmol/g of wet weight tissue (mean +/- SD), respectively. In rabbits receiving
doxorubicin mixed with DSMs, the
tumor and hepatic
drug levels were 59.7 +/- 24.9 and 50.7 +/- 4.8 nmol/g, respectively. The
tumor drug level was significantly higher in the group that received DSMs compared with the group that received only the
drug; the hepatic
drug uptake was unchanged. Peak blood and cardiac
drug levels were decreased by the coinfusion of
drug and DSMs, suggesting that
tumor response rates may be improved and systemic toxicity diminished by the use of DSMs in regional infusion
chemotherapy.