Safety and efficacy of a novel transbronchial radiofrequency ablation system for lung tumours: One year follow-up from the first multi-centre large-scale clinical trial (BRONC-RFII)

Abstract

Background and objective: Radiofrequency ablation (RFA) is an emerging treatment of lung cancer, yet it is accompanied by certain safety concerns and operational limitations. This first multi-centre, large-scale clinical trial aimed to investigate the technical performance, efficacy and safety of an innovative transbronchial RFA system for lung tumours.

Methods: The study enrolled patients with malignant lung tumours who underwent transbronchial RFA using an automatic saline microperfusion system between January 2021 and December 2021 across 16 medical centres. The primary endpoint was the complete ablation rate. The performance and safety of the technique, along with the 1-year survival rates, were evaluated.

Results: This study included 126 patients (age range: 23-85 years) with 130 lung tumours (mean size: 18.77 × 14.15 mm) who had undergone 153 transbronchial RFA sessions, with a technique success rate of 99.35% and an average ablation zone size of 32.47 mm. At the 12-month follow-up, the complete ablation rate and intrapulmonary progression-free survival rates were 90.48% and 88.89%, respectively. The results of patients with ground-glass nodules (GGNs) were superior to those of the patients with solid nodules (12-month complete ablation rates: solid vs. pure GGN vs. mixed GGN: 82.14% vs. 100% vs. 96.08%, p = 0.007). No device defects were reported. Complications such as pneumothorax, haemoptysis, pleural effusion, pulmonary infection and pleural pain were observed in 3.97%, 6.35%, 8.73%, 11.11% and 10.32% of patients, respectively. Two subjects died during the follow-up period.

Conclusion: Transbronchial RFA utilizing an automatic saline microperfusion system is a viable, safe and efficacious approach for the treatment for lung tumours, particularly for patients with GGNs.

Keywords: bronchoscopy; ground‐glass nodule; lung tumour; radiofrequency ablation.

FIGURE 1

The flowchart of patient enrollment and follow‐up process.

FIGURE 2

CT images acquired for preoperative evaluation and of the surgical procedure. (A): CT images acquired for preoperative evaluation. Red arrow: Target lesion. (B): Cone‐beam CT images of intraoperative electrode positioning. Red arrow: Target lesion and RFA electrode. (C): Cone‐beam CT images acquired immediately after ablation. Red arrow: Target ablation zone. (D–H): CT images acquired at 24 h, 1 month, 3 months, 6 months, 12 months. Red arrow: Target ablation zone.

FIGURE 3

Kaplan–Meier survival curves of intrapulmonary progression‐free survival. (A): Subgroup analysis of lesions <2 cm and 2–3 cm in size. (B): Subgroup analysis of solid nodules with ground‐glass nodule.