C110-13 Retrospective Review of Initial Cohort of Bronchoscopic Pulsed Electrical Field Ablations of Malignant Pulmonary Lesions at Tisch Hospital: Safety, Feasibility, Tumor Response, and Induced Immunity

Pulsed electric field (PEF) therapy is a non-thermal, biphasic electrostimulatory pulse applied via a probe to target tissue. This results in electroporation of the cell membrane, leading to cell death and apoptosis, while preserving vasculature and minimally impacting adjacent structures¹. PEF is thought to induce immunostimulatory alterations within the tumor microenvironment, including production of tertiary lymphoid structures (TLS), which have been shown to correlate with overall survival (OS), disease-free survival (DFS), and progression-free survival (PFS), while predicting immunotherapy response even in PD-L1 negative patients. In a propensity-matched cohort study across three centers, percutaneous PEF was found to significantly improve PFS and OS in refractory Stage IV non-small cell lung cancer (NSCLC)3. No major adverse events were reported, as well as no disruption of intra/peritumoral vasculature in post-treatment surgical specimens2. This is a single-center retrospective cohort study using an IRB-approved multi-center registry (PROPEL), including 15 patients by the cutoff date of September 1st, 2025, to investigate the safety and early efficacy of PEF therapy on single lung lesions. Patients had undergone prior therapy, and further resection was not indicated. Patients received between 1-8 cycles of 5-minute PEF activations, depending on tumor volume. The derived neutrophil-to-lymphocyte ratio (dNLR) was assessed both prior to and following PEF treatment. Follow-up imaging was performed an average of 59.8 days post-procedure. In this 15-patient group, only one pneumothorax was reported as an adverse event. Serial CT imaging of 2 out of 3 patients with 90 days post-procedure imaging showed stable disease or partial response (Figure 1). Three patients experienced a decrease in tumor volume, and two patients showed no change. Standard of care peripheral blood draws were performed an average of 25.3 days before the procedure and 63.5 days afterward. In NSCLC, a higher dNLR correlates with poorer PFS and OS with subsequent immunotherapy4. dNLR levels were found to increase on average after PEF therapy. PEF is a safe procedure, and its effectiveness has been shown in a subset of patients. This review included a diverse NSCLC patient group with non-standardized inclusion criteria, which could bias results. It highlights the need for a follow-up RCT to control variables and standardize timing, ruling out pseudo-progression. Future studies should assess PEF’s impact on dNLR, as increased neutrophilic inflammation may hinder T-cell responses and therapies. Planned prospective analyses will examine induced changes in intratumoral and systemic immune responses. Trials will also study neoadjuvant intratumoral/nodal PEF in Stage II/III NSCLC. This abstract is funded by: None