Radiofrequency thermal ablation of hepatocellular carcinoma before liver transplantation--a clinical and histological examination.

Background: Radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC) is an optional treatment for patients awaiting liver transplantation (LTX). The study evaluates the efficacy of RFA in the explanted liver and its effect on patient outcome.
Material and Method: Forty-seven patients underwent RFA and were listed for transplant between January 1998 and May 2003. The patients were divided into two groups: transplanted and non-transplanted. Both groups were evaluated in terms of tumor characteristics, recurrence, mortality rate, and time on the waiting list. The ablation sites in the explanted livers were examined for percentage of necrosis by Hematoxylin & Eosin (H&E) stain and by TUNEL stain.
Results: Transplantation was carried out in 35 patients (74.5%). Ten patients (21.3%) died before transplant or were removed from the wait list, while two patients (4.2%) are still listed. Mortality and tumor-related mortality were significantly higher in the non-transplanted group. The time spent on the waiting list was longer in the non-transplanted patients (350 vs. 186 d average, p = 0.0345). Thirty-eight ablation sites were examined in the explanted livers. The percentage of tumor necrosis by TUNEL staining was 19.6% higher than that reported by H&E staining. After TUNEL staining, 28 sites (73.7%) had more than 90% necrosis, eight sites (21.0%) had 50-90%, and two sites (5.3%) had less than 50% necrosis.
Conclusions: RFA and LTX can be used successfully in HCC patients, and in most cases, tumor necrosis can be achieved with ultrasound-guided RFA. H&E stain tends to under-represent the amount of tumor necrosis on the ablation sites. Survival of RFA patients after LTX is excellent.