Novel Image-Guided Flexible-Probe Transbronchial Microwave Ablation for Stage 1 Lung Cancer

Background: Image-guided percutaneous thermal ablation is an established treatment option for early-stage lung cancer in medically inoperable patients but carries a high risk of pleura-related complications, particularly pneumothorax.

Objective: This study aimed to determine if image-guided transbronchial microwave ablation (tMWA) is a feasible approach to treat peripheral stage 1 lung cancer.

Method: A prospective, single-arm, multicenter study sought to enroll 40 adults who were medically inoperable or declined surgery for peripheral stage 1 lung tumors (≤20 mm). Ablation was performed using navigational bronchoscopy and a flexible MWA probe, guided by cone-beam CT with augmented fluoroscopy. Follow-up at 1, 6, and 12 months included CT imaging of the ablation zone and possible tumor recurrence, adverse events (AEs), pulmonary function, and quality of life.

Results: Across 2 sites, 11 tumors (10 NSCLC, 1 carcinoid) were treated in 10 enrolled patients. Median tumor diameter was 13 × 14 mm (7-19 mm) and median minimum ablative margin was 11 mm (5-19 mm). Technical success and technique efficacy were achieved in all patients. No tumor recurrence was seen during 12-month follow-up. No pneumothorax, pleural effusion, or bronchopleural fistula were noted. Minor AEs included scant hemoptysis, pain, cough, and dyspnea. Two serious AEs occurred ≤30 days of ablation and included a COPD exacerbation (day 9) and a death of unknown cause (day 15). The death led the sponsor to halt enrollment. Pulmonary function and quality-of-life indices remained stable.

Conclusions: Image-guided tMWA is a technically feasible approach for peripheral early-stage lung cancer but warrants further evaluation of safety and efficacy in larger cohorts.