P218 High frequency bronchoscopic microwave ablation for patients with lung cancer: interim results from the United Kingdom

<h3>Introduction</h3> High frequency bronchoscopic microwave ablation (MWA) is a novel alternative to conventional lung cancer treatments. <h3>Aims</h3> To investigate the feasibility of high frequency bronchoscopic MWA in patients with lung cancer. <h3>Methods</h3> We report the interim results of a single arm prospective study enrolling subjects with confirmed malignant or highly suspicious pulmonary nodules ≤20 mm, who are not surgical candidates. <h3>Results</h3> 19 nodules were ablated in 19 subjects. Median age was 73 years. 68.4% were female. 58% of subjects had previous thoracic surgery, radiotherapy, or percutaneous ablation. 17 out of 19 high frequency MWA were delivered robotically. 58% of the nodules were solid; 42% were part-solid. Median baseline long axis nodule length was 9.9 mm. Median distance was 15.1 mm from pleura and 43.1 mm from central zone. Median procedure time was 60 mins, with a median hospital stay length of 1 day. Median length of ablation zone was 27.1 mm at Day1 (n=19), 21.6 mm at 1-month (n=16), 17.1 mm at 3-month (n=15), 16.2 mm at 6-month (n=12) and 14.5 mm at 12-month (n=6). Median patient-reported outcomes are as follows (*p&lt;0.05,**p&lt;0.001 compared to baseline): Disease progression occurred in 1 patient at 6 months, and 1 at 12 months. <h3>Conclusion</h3> Interim data suggests high frequency bronchoscopic MWA may be a feasible alternative for treating patients with lung cancer who are not suitable for surgery, and is associated with low morbidity.