Microwave ablation via a flexible catheter for the treatment of nonsurgical peripheral lung cancer: A pilot study

Abstract

Background: Endobronchial microwave ablation via flexible catheter offers the potential for local therapy for inoperable peripheral lung cancer. The study aimed to evaluate the feasibility and safety of navigation bronchoscopy-guided water-cooled microwave ablation catheter for nonsurgical peripheral lung cancer.

Methods: This was a prospective single arm pilot study. Patients with early stage or multiple primary peripheral lung cancer who were nonsurgical candidates for surgery were enrolled in the study. Bronchoscopic microwave ablation was performed via a flexible water-cooled microwave ablation antenna under the guidance of navigation bronchoscopy. Radial probe endobronchial ultrasound combined with fluoroscopy was used to confirm the position. Treatment outcomes were evaluated based on follow-up chest CT and positron emission tomography scans. Primary endpoints were technical success and safety. Secondary endpoints were complete ablation rate, 2-year local control rate, and progression-free survival.

Results: Thirteen patients were enrolled in the study from April 2018 to July 2019. A total of 19 sessions of microwave ablation were performed on 14 tumors under the guidance of navigation bronchoscopy. The technical success was 100%. Treatment-related complications occurred in two patients. The complete ablation rate was 78.6% (11/14). The 2-year local control rate was 71.4%. Median progression-free survival was 33 months for all patients.

Conclusions: In this pilot study, bronchoscopic microwave ablation appears to be feasible with acceptable occurrence of complication in the treatment of peripheral lung cancer under the guidance of navigation bronchoscopy.

Trial registration: ClinicalTrials.gov NCT02972177.

Keywords: bronchoscopic therapy; lung cancer; microwave ablation; multiple primary lung cancer; navigation bronchoscopy.

FIGURE 1

Treatment‐related complications. Hydropneumothorax and pneumothorax occurred in case 9 (a1–a4) and case 10 (b1–b4), respectively. Chest CT before ablation, showing a tumor in the right middle lobe close to the interlobular fissure and parietal pleura (red arrowhead, a1); chest CT 1 day post‐ablation, showing the ablation area extending to the pleura (a2); chest radiograph 15 days post‐ablation, showing hydropneumothorax on the right (a3); chest CT 15 months post‐ablation, showing a linear lines and scarring shadow in the ablate site (a4); chest CT before ablation, showing the tumor in left upper lobe near to visceral pleura and aortic arch (red arrowhead, b1); chest radiograph 4 h post‐ablation, showing pneumothorax on the left (b2); chest radiograph 1 day after chest tube drainage, showing lung recruitment (b3); chest CT 3 days post‐ablation, showing no pneumothorax (b4)

FIGURE 2

Electromagnetic navigation bronchoscopy (ENB)‐guided microwave ablation for multiple primary lung cancer. The tumor in the left lower lobe underwent microwave ablation with the guidance of ENB in case 10. (a) Real‐time electromagnetic navigation screen of the sensor probe reaching the tumor; (b) ultrasonic image of the tumor; (c) fluoroscopic image of radial probe endobronchial ultrasound (R‐EBUS); (d) fluoroscopic view of the microwave ablation antenna ablating the tumor; (e) chest computed tomography (CT) before ablation; (f–i) chest CT 1 day, 2 months, 5 months, and 15 months post‐ablation, the ablation tumor gradually changed to linear lines and scarring shadow

FIGURE 3

Kaplan–Meier plot for local control and progression‐free survival (PFS). (a) Kaplan–Meier plot for local control in all lesions with a 2‐year local control rate of 71.4 and (b) PFS in all patients with a median PFS of 33 months