Mechanism and Natural Course of Tumor Involution in Hepatocellular Carcinoma Following Transarterial Ethanol Ablation.

PURPOSE: To evaluate the microvascular distribution of lipiodol-ethanol, the histological change of the tumor lesion, and the status of tumor involution over time in hepatocellular carcinoma (HCC) following transarterial ethanol ablation (TEA), in lesions that showed CT evidence of complete tumor response. MATERIALS AND METHODS: Patients with unresectable HCC were treated (183 patients, 242 lesions) with TEA using lipiodol-ethanol mixture (LEM) mixed in 2:1 ratio by volume and followed with CT at 3-month intervals for a median of 14.1 months. Liver tumors (n = 131) that showed CT evidence of complete tumor response, defined as the absence of any enhancing tumor throughout the follow-up period, were included. The surgical specimens of five patients who subsequently received partial hepatectomy were available for histological assessment. The microvascular distribution of LEM and the degree of tumor necrosis were analyzed. Tumor involution over time was assessed with CT in lesions that showed complete response. RESULTS: Lipid stain revealed lipiodol infiltration throughout arterioles, intratumoral sinusoidal spaces, tumor capsule, and peritumoral portal venules. Complete tumor necrosis (100 %) occurred in all 5 surgical specimens. The median (IQR) percentage tumor volume compared to baseline volumes at 12, 36, and 60 months was 32 % (23.5-52.5 %), 22 % (8-31 %), and 13.5 % (6-21.5 %), respectively. CONCLUSION: Intrahepatic HCC lesion that showed CT evidence of complete tumor response following TEA is associated with histological evidence of LEM infiltration throughout the intratumoral and peritumoral vasculature and complete tumor necrosis, as well as sustained reduction in tumor volume over time.

Transarterial Ethanol Ablation for Unresectable Hepatocellular Carcinoma: Analysis of Clinical and Tumor Outcomes.

PURPOSE: To evaluate survival, tumor response, and treatment toxicity of transarterial ethanol ablation (TEA) in patients with unresectable hepatocellular carcinoma (HCC). MATERIALS AND METHODS: This prospective study involved 186 patients (146 men and 40 women; median age, 65 y [interquartile range, 57-72.3 y]). Of 186 patients, 146 (78.5%) were hepatitis B virus carriers, 18 (9.7%) were hepatitis C virus carriers, 82 (44.1%) had tumors ≥ 5 cm, and 43 (23.1%) had multifocal tumors. Overall survival (OS), complete response (CR) by European Association for the Study of the Liver criteria, time to progression (TTP), progression-free survival (PFS), and treatment toxicities were evaluated. Univariate and multivariate analyses for prognostic factors of OS were performed. RESULTS: Median OS was 25.7 months (95% confidence interval [CI], 20.9-30.5) and varied significantly between Child-Pugh A and B (28.7 mo vs 13.4 mo, P < .001), and Barcelona Clinic Liver Cancer A and B or C (37.1 mo vs 17.7 mo, P = .001). Prognostic factors for longer OS were solitary tumor, tumor size < 5 cm, > 1 treatments, and CR of all tumors at 6 months. TTP was 9.1 months (95% CI, 6.9-11.3). PFS was 8.4 months (95% CI, 7.1-9.7). CR occurred in 69.1% (159/230) of lesions and 48.9% (88/180) of patients at 6 months. Any one symptom of the postembolization syndrome of grade 2 severity occurred in < 22% (41/186) of patients. No treatment-related hepatitis or death occurred within 30 days. Transient respiratory decompensation occurred in three patients (1.6% [3/186]), and alcoholic intoxication occurred in one patient (0.5% [1/186]). CONCLUSIONS: TEA appears to be safe and effective for local control of HCC.