Advanced hepatocellular carcinoma: CT perfusion of liver and tumor tissue - Initial experience

Purpose: To prospectively assess computed tomographic ( CT) perfusion for evaluation of tumor vascularity of advanced hepatocellular carcinoma ( HCC) and to correlate CT perfusion parameters with tumor grade and serum markers. Materials and Methods: The study was HIPAA compliant and was approved by the institutional review board. Patients provided informed consent. Thirty patients ( 22 men, eight women; mean age, 60 years; range, 28-79 years) with unresectable or metastatic HCC were studied. Dynamic first-pass CT perfusion was performed in primary ( n = 25) and metastatic ( n = 5) HCCs after intravenous injection of contrast medium. Data were analyzed to calculate tissue blood flow, blood volume, mean transit time, and permeability-surface area product. Repeat examination was performed in four patients within 30 hours to test reproducibility of CT perfusion. CT perfusion parameters were compared among tumors of different grades, with presence or absence of portal vein invasion, with presence or absence of cirrhosis, and of various extrahepatic metastases. Parameters were correlated with HCC serum markers. One-way analysis of variance was used to calculate variations in CT perfusion parameters. Results: Good correlation ( r = 0.9, P <= .01) was observed between repeat examination results and first CT examination results. There was a significant difference ( P <= .05) in CT perfusion parameters between primary HCC and background liver parenchyma. Well-differentiated HCC showed significantly higher perfusion values ( P <= .05) than other grades. There was no significant difference in tumor perfusion between presence or absence of portal vein invasion or cirrhosis. Lymph node metastasis demonstrated lower values compared with metastases from other extrahepatic sites. There was no significant correlation between CT perfusion parameters and serum markers. Conclusion: Results suggest that CT perfusion is a feasible and, from the limited data, reproducible technique for quantifying tumor vascularity and angiogenesis in advanced HCC. (c) RSNA, 2007.