Radiofrequency ablation followed by resection of malignant liver tumors

BACKGROUND: Radiofrequency ablation (RFA) has recently been used to treat liver tumors, but few clinical reports have described the pathological characteristics of radiofrequency ablation in human specimens, This study delineates the gross pathologic and histochemical changes induced by RFA in benign and malignant human liver tissue and confirms the tumor necrosis described in early clinical reports. METHODS: Ten patients with metastatic tumors of the liver received a single treatment of ultrasound-guided percutaneous RFA to 12 tumors. Hepatic resection was carried out within 6 weeks of RFA. Specimens were stained with standard hematoxylin and eosin stain followed by oxidative stain to determine if there was evidence of viable tumor within the zone of ablation. RESULTS: Nine of the 12 ablations were resected. Microscopic examination within the zone of ablation showed successful ablation in 8 of the 9 resected ablations. CONCLUSIONS: Percutaneous RFA creates well-circumscribed areas of tumor necrosis with apparent cell death using an oxidative stain. Further investigation is encouraged to determine the clinical effectiveness of radiofrequency ablation in the complete destruction of liver tumors for palliative or curative intent. Am J Surg. 1999; 177:411-417. (C) 1999 by Excerpta Medica, Inc.