Oxygen-15 positron-emission tomography for predicting selective delivery of a chemotherapeutic agent to hepatic cancers during angiotensin II-induced hypertension

Abstract

Selective drug delivery is important for successful chemotherapy. In patients with hepatic cancer, we used (15)O-carbon dioxide (steady-state) and (15)O-water (dynamic) positron emission tomography (PET) to evaluate changes in blood flow induced by angiotensin (AT) II in the liver parenchyma, hepatic tumors, and spleen. The study group comprised 13 patients, 6 with hepatic metastasis and 7 with hepatocellular carcinoma. PET was performed before and during AT II administration to induce hypertension. Steady-state PET images showed a preferential increase in blood flow to hepatic tumor compared with liver parenchyma during hypertension. In dynamic PET, tumor blood flow was maintained during induced hypertension while hepatic arterial blood flow, portal blood flow, total hepatic blood flow, and splenic blood flow decreased to 71.4% (not significant), 65% (P<0.01), 67.2% (P<0.001), and 72.3% (P<0.01) of the respective baseline values. AT II-induced hypertension produced a relative increase in tumor blood flow. Oxygen-15 PET should be useful for predicting preferential drug delivery to hepatic cancers.