96P Transbronchial microwave ablation: Important role in the battle of lung preservation for multifocal lung primaries or metastases

Abstract

Multifocal small, deep and subsolid lung nodules are increasingly discovered incidentally, often harboring early malignancies. In these cases, lung-preservation rather than major lung resection is the optimal strategy of choice. We retrospectively reviewed all lung nodules treated by electromagnetic navigation bronchoscopy (ENB) transbronchial microwave ablation between March 2019 and January 2022. Among these, we extract the case series of patients with multifocal lung cancers or oligometastases which have been managed by ENB ablation with or without other forms of local treatment. Among 80 patients treated with ENB microwave ablation in the hybrid operating room, 17 had multiple lung nodules which were suspicious of or confirmed malignancies. Reason for lung preserving strategy includes multi-lobar location of nodules (70.6%), inadequate lung function (23.5%), previous major lung resection (17.6%) and patient preference (11.7%). All nodules were relatively deep (mean of 14mm from pleural surface) and small (mean of 11mm in diameter). Eight patients were histologically proven primary lung cancers or metastases, while the rest were highly suspicious of malignancies. Seven patients had ENB ablation for two or more nodules in the same session, while 7 had ENB ablation on separate occasions. Four patients had concurrent wedge resection of other lung nodules in the same operative session. Technically success rate was 100%, and the average length of hospital stay was 1.3 days after same session ENB ablation, and 2 days after concurrent wedge resection. No complications were encountered except mild pain (17.6%) or low grade fever (5.9%). Over a median follow up of 13 months, there was 1 local recurrence which was subsequently treated with stereotactic radiotherapy and 1 local plus distant metastases which was managed by systemic chemotherapy. ENB ablation can be combined with other multimodality treatments including surgical wedge resection, radiotherapy, or percutaneous local ablation, providing personalized therapeutic options. It is an important armamentarium in tackling multifocal lung cancers or oligometastases, as part of lung-preserving strategy.