Correlation of multislice CT and histomorphology in HCC following TACE: predictors of outcome

The purpose of this study was to correlate histopathological with CT findings in patients suffering from hepatocellular carcinoma (HCC) eligible for orthotopic liver transplantation (OLT), with a special focus on the antitumoral effect of transarterial chemoembolization (TACE) therapy. A total of 42 consecutive patients suffering from HCC had been treated prior to OLT by means of TACE. TACE was carried out with a mixture of Lipiodol (10-20 ml) and mitomycin C (max. dosage, 10 mg). TACE was performed at 6- to 8-week intervals. Follow-up investigation included contrast-enhanced multislice CT controls and laboratory control. Liver explants were evaluated macroscopically and microscopically to determine the number and size of the tumor lesions as well as the degree of tumor necrosis. Necrosis was investigated in H&E-stained sections. The degree of necrosis was classified as follows: 0-25%, 26-50%, 51-75%, 75-99%, and complete necrosis. Two hundred thirty-one TACE procedures (5.5 +/- 2.9; range, 1-14) were performed. Mean tumor size in CT before and after TACE was 4.1 +/- 2.4 (range, 1.0-12.0 cm) and 2.7 +/- 1.2 (range, 1.0-6.0 cm; p < 0.001). Mean tumor number before and after TACE in CT was 2.5 +/- 1.5 (n = 105; range, 1-8) and 2.4 +/- 2.0 (n = 103; range, 1-6; p = 0.99). In the surgical specimen tumor size and tumor number were 2.8 +/- 1.6 (range, 1.0-7.0 cm; p = 0.78) and 1.9 +/- 1.2 (range, 1-7; p = 0.003). Mean tumor necrosis was 67.8% +/- 28.1%. Tumor necrosis was subtotal or complete in 17 of 42 (40.5%) patients. Tumor necrosis correlated significantly with the degree of arterial devascularization in CT (p = 0.001), the amount of Lipiodol washout (p = 0.002), and the number of tumor lesions (i.e., unifocal vs. multifocal). Furthermore, elevated serum levels of bilirubin (p = 0.005) and decreased albumin (p = 0.004) affected the local antitumoral effect. A poor necrosis rate (< 25%) significantly correlated with the number of TACE procedures accomplished (p = 0.023). In conclusion, TACE provided an acceptable local antitumoral effect in patients scheduled for liver transplantation. Tumor necrosis depended significantly on the degree of arterial devascularization and the accumulation of Lipiodol within the HCC lesions. Unifocal tumors and preserved liver function were positive predictors for a more favorable local antitumoral effect. Poor necrosis rates were found in patients with significant Lipiodol washout and who received a limited number of TACE procedures.