Correlation of Multislice CT and Histomorphology in HCC Following TACE: Predictors of Outcome

Abstract

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.

Intraprocedural 3D Quantification of Lipiodol Deposition on Cone-Beam CT Predicts Tumor Response After Transarterial Chemoembolization in Patients with Hepatocellular Carcinoma

“…Although overall survival continues to be the ultimate end point in cTACE clinical trials, imaging biomarkers of tumors response are frequently used as surrogates for TACE efficacy [3-5]. In this context, identifying non-responders as early as possible is of high clinical relevance for the decision on whether or not to retreat the patient [6,7].…”

“…In this context, identifying non-responders as early as possible is of high clinical relevance for the decision on whether or not to retreat the patient [6,7]. Some studies have identified intratumoral Lipiodol deposition as a strong biomarker of tumor necrosis and have confirmed it to be a predictor of tumor response and potentially survival outcomes after cTACE [3,5,8-12]. Many of these reports relied on post-procedural multi-detector CT (MDCT) in order to assess the Lipiodol distribution after cTACE, thus making the feedback available only upon completion of the procedure.…”

Imaging predictors of the response to transarterial chemoembolization in patients with hepatocellular carcinoma: A radiological-pathological correlation

“…The experience with correlating imaging features of HCC lesions after TACE with findings from pathological analysis has been limited9‐13 because only a minority of patients are candidates for resection or liver transplantation. Nevertheless, it has been suggested that dense tumor staining with ethiodized oil12 and a lack of residual enhancement9, 11, 13 on post‐TACE computed tomography (CT) are associated with a greater extent of tumor necrosis upon pathological analysis. Because cross‐sectional imaging remains an essential tool for diagnosing recurrent or residual disease after liver‐directed therapy, the identification of reliable imaging predictors of tumor responses to TACE is important.…”

Pattern of Retained Contrast on Immediate Postprocedure Computed tomography (CT) After Particle Embolization of Liver Tumors Predicts Subsequent Treatment Response

“…Response was defined as follows: complete response (CR) as disappearance of all intratumoral enhancement; partial response (PR) as >30 % decrease in diameters of enhancing tumor from baseline; progressive disease (PD) as >20 % increase in diameters of enhancing tumor from baseline; and stable disease (SD) as all other tumors. Enhancement >10 Hounsfield units (HU) on arterial phase compared with noncontrast phase was considered enhancement [19, 20]. The morphology of residual enhancing tumor was described as partial, circumferential, or total.…”