A Multi-Center, Prospective Study of Transbronchial Radiofrequency Ablation for Peripheral Lung Tumors: Study Progress and Initial Results

Introduction: A novel transbronchial radiofrequency ablation (RFA) system is conducted with program-controlled saline microperfusion, which can stabilize the impedance and provide constant power during ablation. This study aims to evaluate the safety and efficacy of transbronchial RFA for peripheral lung tumors. Methods: We conducted a multicenter, prospective, single-arm study (NCT04619472) of transbronchial RFA in patient with NSCLC and metastatic lung cancer. Subjects were followed up for 12 months with CT-based assessment of complete ablation rate (CA%) as the efficacy endpoint. Results: By the time of data collection, 126 eligible subjects (73 males and 53 females; mean age 64 ± 13 years) had been enrolled in 16 sites from China. 124 subjects completed 6-month follow-up and 76 subjects completed 12-month follow-up. 153 sessions of RFA (including 23 sessions of supplementary ablation) were performed on 130 lung lesions, with a technical success rate of 99.3% (152/153). The mean lesion size was 18.78 ± 6.28mm. As the investigator evaluated, CA% was 92.1% (116/126) and 82.9% (63/76) at 6 and 12 months respectively. The 12-month OS% was 96.1%. The 6-month CA% of supplementary ablation was 95.4% (21/22). CTCAE Grade 3 or above adverse events related to ablation occurred in 41 of 148 (28%), of which pulmonary inflammation (24/41), pulmonary infection (5/41), chest pain (2/41), pneumothorax (3/41), pleural effusion (1/41) and hemoptysis (1/41) were the common cause. Conclusion: The initial results demonstrate that transbronchial RFA is a safe and effective treatment for peripheral lung tumors. The results will be presented after the study completed.