Radiofrequency ablation: a minimally invasive technique with multiple applications.

PURPOSE

Radiofrequency ablation (RFA) of soft tissue, which has recently been approved by the United States Food and Drug Administration, destroys tumor cells by delivering an electrical current through a 15-gauge needle. This study evaluated RFA for patients with hepatic malignancies considered unresectable because of their distribution, their number, and/or the presence of liver dysfunction.

PATIENTS AND METHODS

Between November 1997 and February 1999, 50 patients with 132 unresectable hepatic metastases underwent RFA of tumors from 0.5 to 9 cm in diameter. There were 41 colorectal metastases in 22 patients, 13 hepatomas in seven patients, 37 neuroendocrine metastases in six patients, and 41 noncolorectal metastases in 15 patients. Real-time ultrasonography was used to guide RFA, and lesions were ablated by applying temperatures of approximately 100 degrees C for 8 minutes. Overlapping ablations were used for larger lesions. In patients with multiple lesions, RFA was performed simultaneously with cryosurgery, resection, and/or hepatic arterial infusion.

RESULTS

RFA was undertaken percutaneously on an outpatient basis in 13 patients (25 lesions). The remaining patients underwent RFA via laparoscopy (21 patients; 58 lesions) or celiotomy (16 patients; 49 lesions); mean hospital stay was 1 and 5 days, respectively. RFA was the sole therapy in 28 patients and was additional therapy in 22 patients. At a median follow-up of 6 months, 27 patients were free of disease, 17 were alive with disease, and six had died of their disease (three colon, three melanoma). Three patients whose disease recurred at a prior RFA site underwent successful percutaneous RFA. Overall, there was a significant postoperative reduction in levels of carcinoembryonic antigen, alpha-fetoprotein, serotonin, and 5-hydroxyindoleacetic acid. Intraoperative ultrasonography identified unrecognized hepatic lesions in 12 of 37 patients (32%); these lesions were successfully ablated. When performed with cryosurgery, RFA reduced the morbidity of multiple freezes.

DISCUSSION

RFA is a safe and effective alternative for the ablation of unresectable hepatic malignancies and when used adjunctively can reduce the morbidity of cryosurgery. Percutaneous and laparoscopic RFA can be performed effectively with less than 24 hours of hospitalization. Intraoperative ultrasonography is essential for accurate staging.