Radiofrequency Ablation Using a Monopolar Wet Electrode for the Treatment of Inoperable Non-Small Cell Lung Cancer: a Preliminary Report

OBJECTIVE: To assess the technical feasibility and complications of radiofrequency ablation (RFA) using a monopolar wet electrode for the treatment of inoperable non-small cell lung malignancies. MATERIALS AND METHODS: Sixteen patients with a non-small cell lung malignancy underwent RFA under CT guidance. All the patients were non-surgical candidates, with mean maximum tumor diameters ranging from 3 to 6 cm (mean: 4.6 ± 1.1 cm). A single 16-gauge open-perfused electrode with a 2 cm exposed tip was used for the procedure. A 0.9% NaCl saline solution was used as the perfusion liquid with the flow adjusted to 30 mL/h. The radiofrequency energy was applied for 10-40 minutes. The response to RFA was evaluated by performing contrast-enhanced CT immediately after RFA, one month after treatment and then every three months thereafter. RESULTS: Technical failure was observed in six (37.5%) of 16 patients: intractable pain (n = 2) and non-stop coughing (n = 4). The mean follow-up interval was 15 ± 8 months (range: 9-31 months). The mean maximum ablated diameter in the technically successful group of patients ranged from 3.5 to 7.5 cm (mean 5.1 ± 1.3 cm). Complete necrosis was attained for eight (80%) of 10 lesions, and partial necrosis was achieved for two lesions. There were two major complications (2/10, 20%) encountered: a hemothorax (n = 1) and a bronchopleural fistula (n = 1). CONCLUSION: Although RFA using a monopolar wet electrode can create a large ablation zone, it is associated with a high rate of technical failure when used to treat inoperable non-small cell lung malignancies.