SESSION TITLE: Modern Approaches to the Diagnosis of Lung Cancer Across Multiple Populations SESSION TYPE: Original Investigations PRESENTED ON: October 18-21, 2020 PURPOSE: Surgery remains the standard-of-care for patients with early-stage lung cancer. However, many patients are medically inoperable due to significant comorbidities. Image-guided percutaneous thermal ablation (radiofrequency/microwave) is an established alternative to radiation therapy for such patients. Thermal ablation has been shown to have similar results as radiation therapy while preserving lung function, though it carries specific risks when used transthoracically, such as pneumothorax rates ranging from 12%-33%. This study’s purpose was to examine the efficacy and safety profile of image-guided transbronchial microwave ablation (MWA) of primary lung tumors. METHODS: A prospective, multi-center study enrolled patients June-November 2018. Main inclusion criteria were patients with primary tumors <20mm in the outer two-thirds of the lung and who were medically inoperable or refused surgery. Patients were reviewed in a multidisciplinary conference. Navigation to the tumor was performed using electromagnetic navigation bronchoscopy combined with cone-beam CT (CBCT) with augmented fluoroscopy while patients were under general anesthesia. CBCT was used to confirm probe position and final ablation zone. Additional ablations were carried out as necessary to achieve satisfactory margins. RESULTS: Ten patients across two sites with 11 primary tumors were treated (6 female). Mean tumor diameter was 14.0mm (range: 8.0-19.0mm). The average number of ablations per tumor was 2 (range: 1-3). The majority of the tumors were in the upper lobes (N=6). The average minimum margin measured in all planes was 11.4mm (range: 5.2-19.0mm). Two deaths occurred during the 12-month follow-up period (the first occurred 15 days post-ablation and the second occurred after the 6-month visit). An independent DSMB reviewed both deaths and determined the first death to be possibly-related to the device and probably-related to the procedure and the second death to be not related to either the device or procedure. There was no pneumothorax or clinically significant hemoptysis in remaining patients. The most common side effects included scant hemoptysis, cough, and short-term chest wall pain. According to site treating physicians, all patients achieved Technique Efficacy (complete tumor ablation with an adequate margin) at 1 month. At the time of study closure, no local recurrence had been diagnosed by the treating physicians. Subsequent clinical follow-up at 18 months identified tumor recurrence in one patient. CONCLUSIONS: Image-guided transbronchial MWA of primary lung tumors has an emerging favorable benefit-risk profile that warrants evaluation in larger patient cohorts. CLINICAL IMPLICATIONS: Pending further studies, transbronchial MWA may become a viable treatment option for patients with early-stage lung cancer or lung metastasis who are not candidates for other therapies. DISCLOSURES: No relevant relationships by Ryan Kern, source=Web Response Consultant relationship with Ethicon/NeuWave Medical Please note: $20001 - $100000 Added 06/11/2020 by Paul Laeseke, source=Web Response, value=Consulting fee Consultant relationship with HistoSonics Please note: $20001 - $100000 Added 06/11/2020 by Paul Laeseke, source=Web Response, value=Ownership interest Investor relationship with HistoSonics Please note: >$100000 Added 06/11/2020 by Paul Laeseke, source=Web Response, value=Ownership interest Consultant relationship with Elucent Medical Please note: $5001 - $20000 Added 06/11/2020 by Paul Laeseke, source=Web Response, value=Ownership interest Investor relationship with Elucent Medical Please note: >$100000 Added 06/11/2020 by Paul Laeseke, source=Web Response, value=Ownership interest Employee relationship with ETHICON, Inc. Please note: >$100000 Added 05/10/2020 by Erin Meyers, source=Web Response, value=Salary My spouse/partner as a Employee relationship with Medtronic Please note: >$100000 Added 04/18/2020 by Michael Pritchett, source=Web Response, value=Salary Consultant relationship with Medtronic Please note: $5001 - $20000 Added 04/18/2020 by Michael Pritchett, source=Web Response, value=Consulting fee Consultant relationship with Johnson & Johnson Please note: $5001 - $20000 Added 04/18/2020 by Michael Pritchett, source=Web Response, value=Consulting fee Consultant relationship with AstraZeneca Please note: $20001 - $100000 Added 04/18/2020 by Michael Pritchett, source=Web Response, value=Consulting fee Consultant relationship with Intuitive Please note: $20001 - $100000 Added 04/18/2020 by Michael Pritchett, source=Web Response, value=Consulting fee Consultant relationship with BodyVision Please note: $5001 - $20000 Added 04/18/2020 by Michael Pritchett, source=Web Response, value=Consulting fee Consultant relationship with Boston Scientific Please note: $1001 - $5000 Added 04/18/2020 by Michael Pritchett, source=Web Response, value=Consulting fee Research relationship with Philips Please note: $5001 - $20000 Added 04/18/2020 by Michael Pritchett, source=Web Response, value=Grant/Research Support Consultant relationship with Biodesix Please note: $5001 - $20000 Added 04/18/2020 by Michael Pritchett, source=Web Response, value=Consulting fee Research grant relationship with Intuitive Surgical Please note: $5001 - $20000 Added 05/28/2020 by Janani Reisenauer, source=Web Response, value=Grant/Research Support Employee relationship with Ethicon Inc Please note: >$100000 Added 05/18/2020 by Leonie Rynn, source=Web Response, value=Salary no disclosure on file for David Wilson