297P - Transbronchial microwave ablation of early lung cancers and lung oligometastases: Mid-term results

Background

Microwave ablation of lung nodules provides a faster, larger and more predictable ablation zone than its predecessor radiofrequency energy, while bronchoscopic ablation has advantage of less pleural-based complications than percutaneous approach. The combination of bronchoscopic approach and microwave ablation is a novel approach in local treatment of lung nodules.

Methods

Ninety-nine lung nodules in 79 patients who underwent electromagnetic navigation bronchoscopy microwave ablation in hybrid operating room from March 2019 to June 2022 were retrospectively reviewed. Patients either refused surgery or had significantly high surgical risks. Eligible lung nodules were either proven lung cancers, metastases, or radiologically suspicious. Feasibility, safety and mid-term control rate of the technique were assessed.

Results

Mean maximal diameter of lung nodules was 14.2mm (range 6-29mm), and bronchus sign was positive in 38.4% of them. Technical success rate was 100%, although 35 nodules required double ablation for adequate coverage. Mean minimal ablation margin was 5.9mm. There was no significant heat sink effect. Mean hospital stay was 1.65 days, 78 cases (79%) and 94 cases (95%) were discharged by post-ablation day 1 and 3 respectively. Complications included mild pain which did not require hospitalization (8.0%), pneumothorax requiring drainage (5.0%), post-ablation reaction (3.0%), pleural effusion (1%) and hemoptysis (1%). Median follow up for all cases is 18.5 months. For the 50 nodules which had completed 1-year follow up computer tomography scan, 2 had complete response, 31 had partial response, 11 had stable disease, and 6 (12.0%) had progressive disease, which includes both local and distant recurrence. Ablation site recurrence occurred in only 5 patients, of which 2 is accompanied by widespread distant metastases.

Conclusions

Transbronchial microwave ablation is a safe and novel ablative technique for early stage lung cancers, lung metastases or highly suspicious lung nodules in selected cases, and has an encouraging mid-term local control rate.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

R. Lau: Non-Financial Interests, Institutional, Advisory Role: Medtronic, Siemens Healthineers. C. Ng: Non-Financial Interests, Institutional, Advisory Role: Medtronic, Siemens Healthineers, Johnson & Johnson. All other authors have declared no conflicts of interest.