Intraoperative Radiofrequency Ablation of Lung Metastases and Histologic Evaluation

Background: Radiofrequency ablation (RFA) has received high interest in the treatment of primary and secondary lung neoplasms. Clinical experience continues to accumulate; however, the biologic effects after ablation remain poorly understood. This study evaluated the safety and feasibility of RFA in an open thoracotomy setting and investigated the early histopathologic changes after RFA. Methods: The study enrolled 18 subjects with multiple pulmonary metastases from a solid primary tumor. RFA was performed at an open thoracotomy setting, followed by wedge resection of the ablated tumor. Results: No intraoperative complications during the RFA procedure occurred. Immunostaining revealed a complete ablation in 7 patients (39%). The grade of ablation was greater than 90% in 9 patients (50%), and less than 90% in 2 (11%). No correlation was found between the grade of ablation and the applied energy and the diameter of the lesion. Conclusions: Intraoperative RFA in an open thoracotomy setting appears to be a safe and feasible technique. Tumor devitalization sufficient for local control was achieved in 89% in our series. Ablation was incomplete in 11%, subject to the methods used in this study. This result appears to be inferior to metastasectomy by surgical resection.