Histologic Evaluation and Treatment Outcome after Sequential Radiofrequency Ablation and Hepatic Resection for Primary and Metastatic Tumors

Abstract

Operative manipulation during hepatic resection (HR) causes tumor cell shedding which is a factor in disease recurrence. Radiofrequency ablation (RFA) causes coagulative necrosis and was used to destroy the tumor before HR. We evaluated tumor necrosis and recurrence of hepatic malignancies treated by sequential RFA/HR. A retrospective review of patients treated with sequential RFA/HR from April 1999 to January 2002 was performed. A Radionics 500-kW RF generator was used to ablate lesions via H2O-cooled electrodes under ultrasound guidance. Segmental HR was performed after RFA. Resected specimens were reviewed with hematoxylin and eosin staining and for apoptosis. Patient follow-up ranged from 10 to 33 months with evaluation of salient clinical, radiologic, and laboratory parameters. Seven patients (four male and three female) ages 62.1 ± 10.3 years had sequential RFA/HR. Four patients had hepatocellular carcinoma (HCC) and three had colorectal metastases (CRm). The tumors were unifocal right-lobe lesions measuring 4.1 ± 0.9 cm with a resection margin of 0.4 to 2.5 cm. Extensive necrosis was noted but intact nests of tumor cells occurred in all specimens with minimal apoptosis. Three of seven patients (two HCC and one CRm) developed pulmonary metastases at 3 to 20 months with one HCC patient developing concurrent liver metastases. Two deaths occurred in the HCC group. Sequential RFA/HR may minimize local recurrence; however, the high incidence of pulmonary metastases raises concern of transvenous migration. The histologic findings demonstrate foci of intact tumor cells after RFA. Controlled study of additional patients with long-term follow-up is necessary to better understand these findings.