Angiotensin-II-induced hypertension chemotherapy: evaluation of hepatic blood flow with oxygen-15 PET.

We quantitatively measured blood flow in liver parenchyma and hepatic tumors in two patients using 15O-carbon dioxide (steady state) and 15O-water (dynamic) PET imaging. Images were acquired before and during administration of angiotensin-II to achieve a hypertensive state. Blood flow in the hepatocellular carcinoma was greater than that of the parenchyma. Blood flow in the colon metastasis was similar to that in the parenchyma and lower in the center than in the periphery. During a hypertensive state induced by angiotensin II, blood flow in both the primary and secondary liver tumors did not change, while blood flow in the liver parenchyma decreased. As a result, there was a relative increase in tumor blood flow during the hypertensive state on PET images. Furthermore, blood flow to the spleen decreased to 55% of baseline during the hypertensive state. These findings suggest that hypertensive cancer chemotherapy may protect normal tissue. Furthermore, PET imaging may be able to predict the efficacy of hypertensive cancer chemotherapy in the patients with liver tumors.