Assessment of Radiofrequency Ablation Efficacy for Hepatocellular Carcinoma by Histology and Pre-transplant Radiology

Radiofrequency ablation (RFA) represents a potentially curative option for hepatocellular carcinoma (HCC) in the early stages. This study aims at evaluating the histologic response after RFA of small HCCs arising in cirrhosis. Data from 78 patients with de-novo HCCs, treated with RFA and subsequently transplanted were reviewed. The last radiological assessment before liver transplantation (LT) was used for comparison between Modified Response Evaluation Criteria in Solid Tumors (mRECIST) and histological findings. A total of 125 de-novo HCCs (median diameter: 20mm) were treated with RFA only in 92 sessions. Ninety-eight nodules did not show local recurrence during follow-up (78.4%), the remaining were retreated, except one because of subsequent LT. On explanted livers, complete pathological response (CPR) was observed in 61.6%, being 76.9% when <2cm, 55.0% when 2-3cm and 30.8% when >3cm. Tumors near to hepatic vessels had CPR in 50% of cases versus 69.3% for tumors distant from vessels (p=0.039). Of the 125 HCCs, 114 had available radiological assessment within a median of 3 months before LT. mRECIST complete was observed in 77.2% of nodules before LT. The k-Cohen was 0.48 (moderate agreement). The overall accuracy was of 78.1%. A total of 18 complications were recorded, only one graded as major. CONCLUSIONS: RFA can provide high CPR for HCC, especially in smaller tumors distant from hepatic veins or portal branches. The agreement between mRECIST and histology is only moderate. Further refinements in radiological assessment are essential to accurately assess the true effectiveness of RFA. This article is protected by copyright. All rights reserved.