Optimal
chemotherapy delivery to the
tumor depends on regional
drug concentration,
tumor perfusion, tissue
drug uptake, and metabolism. Modulation of
tumor blood flow has been used to improve
tumor response to treatment. Transient microembolization is one method to alter regional blood flow, but its effects on relative changes in
tumor and liver blood flow have not been previously measured. This study used quantitative perfusion fluorometry (QPF) to evaluate blood flow distribution in liver and
tumor before and after hepatic arterial infusion of
degradable starch microspheres (DSMs) in 10 New Zealand white rabbits. QPF was compared with radioactive
xenon-133 washout, an established method for measuring blood flow.
Xenon-133 was injected intraparenchymally and the clearance rate was measured allowing calculation of relative blood flow. QPF was then used to measure liver and
tumor blood flow in a hepatic VX-2
tumor model after hepatic artery injection of DSMs. Initial
tumor blood flow was 55% of liver flow. DSMs produced a significant and transient decrease in hepatic blood flow that was decreased to 40% of baseline after 25 min. Changes in relative hepatic blood flow after DSMs as measured by QPF correlated strongly with results obtained by
xenon-133 washout (R = 0.97, P less than 0.01). Fluorometry's simplicity and reliability may be clinically useful to evaluate
tumor blood flow characteristics.