Bronchoscopic Thermal Vapour Ablation for Localized Cancer Lesions of the Lung: A Clinical Feasibility Treat-and-Resect Study.

BACKGROUND Bronchoscopic thermal vapour ablation (BTVA) is an established and approved modality for minimally invasive lung volume reduction in severe emphysema. Preclinical data suggest potential for BTVA in minimally invasive ablation of lung cancer lesions. OBJECTIVES The objective of this study is to establish the safety, feasibility, and ablative efficacy of BTVA for minimally invasive ablation of lung cancers. METHODS Single arm treat-and-resect clinical feasibility study of patients with biopsy-confirmed lung cancer. A novel BTVA for lung cancer (BTVA-C) system for minimally invasive treatment of peripheral pulmonary tumours was used to deliver 330 Cal thermal vapour energy via bronchoscopy to target lesion. Patients underwent planned lobectomy to complete oncologic care. Pre-surgical CT chest and post-resection histologic analysis were performed to evaluate ablative efficacy. RESULTS Six patients underwent BTVA-C, and 5 progressed to planned lobectomy. Median procedure duration was 12 min. No major procedure-related complications occurred. All 5 resected lesions were part-solid lung adenocarcinomas with median solid component size 1.32±0.36 cm. Large uniform ablation zones were seen in 4 patients where thermal dose exceeded 3 Cal/mL, with complete/near-complete necrosis of target lesions seen in 2 patients. Tumour positioned within ablation zones demonstrated necrosis in >99% of cross-sectional area examined. CONCLUSION BTVA of lung tumours is feasible and well tolerated, with preliminary evidence suggesting high potential for effective ablation of tumours. Thermal injury is well demarcated, and uniform tissue necrosis is observed within ablation zones receiving sufficient thermal dose per volume of lung. Treatment of smaller volumes and ensuring adequate thermal dose may be important for ablative efficacy.