Radiofrequency ablation: A minimally invasive technique with multiple applications

1 PURPOSE Radiofrequency ablation (RFA) of soft tissue, which has recently been appro ved 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 unresectabl e because of their distribution, their number, and/or the presence of liver dysfunction. 2 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. Th ere were 41 colorectal metastases in 22 patients, 13 hepatomas in seven pat ients, 37 neuroendocrine metastases in six patients, and 41 noncolorectal m etastases in 15 patients. Real-time ultrasonography was used to guide RFA, and lesions were ablated by applying temperatures of approximately 100 degr ees C for 8 minutes. Overlapping ablations were used for larger lesions. In patients with multiple lesions, RFA was performed simultaneously with cryo surgery, resection, and/or hepatic arterial infusion. 3 RESULTS RFA was undertaken percutaneously on an outpatient basis in 13 patients (25 lesions). The remaining patients underwent RFA via laparoscopy (21 patient s; 58 lesions) or celiotomy (16 patients; 49 lesions); mean hospital stay w as 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, 2 7 patients were free of disease, 17 were alive with disease, and six had di ed of their disease (three colon, three melanoma). Three patients whose dis ease recurred at a prior RFA site underwent successful percutaneous RFA. Ov erall, there was a significant postoperative reduction in levels of carcino embryonic antigen, alpha-fetoprotein, serotonin, and 5-hydroxyindoleacetic acid. Intraoperative ultrasonography identified unrecognized hepatic lesion s in 12 of 37 patients (32%); these lesions were successfully ablated. When performed with cryosurgery, RFA reduced the morbidity of multiple freezes. 4 DISCUSSION RFA is a safe and effective alternative for the ablation of unresectable he patic malignancies and when used adjunctively can reduce the morbidity of c ryosurgery. Percutaneous and laparoscopic RFA can be performed effectively with less than 24 hours of hospitalization. Intraoperative ultrasonography is essential for accurate staging.