Abstract No. 549 Early Experience Using Pulsed Electric Fields (PEF) in Metastatic Disease to the Lung

To discuss our early experience using Pulsed Electrical Field (PEF) in the treatment of metastatic disease to the lung. A retrospective review of patients with refractory metastatic disease to the lung who were treated with PEF. A single lesion was treated in 7 patients. Response Evaluation Criteria in Solid Tumors (RECIST) measurements were performed on the lesion that was ablated as well as up to two additional lung lesions and lesions within other organs as appropriate. Tumor markers were also collected in patients as appropriate. In our experience to date, we have followed up on 7 patients with advanced metastatic disease to the lung. Three patients with colorectal cancer, one with renal cell and 3 with primary lung cancer. Our mean follow up time is 88.8 (± 16.3; median 85) days. Table 549.1 shows the responses (by RECIST 1.1) and cancer type for each patient. 28.6% (2/7) of patients showed partial response while 57.1% (4/7) showed stable disease. Only one patient showed evidence of progressive disease at these follow up. In addition, the three patients with colorectal cancer has seen significant changes in their CEA as outlined in Table 549.2. After ablation there is a significant increase in the patients CEA levels which subsequently decrease. In the patient with progressive disease there is a subsequent increase in CEA suggesting progression. Although extremely early, our experience with the use of PEF in patients in refractory metastatic disease to the lung, showed more than 50% of the patients with stable disease. Two patients showed evidence of an abscopal effect with greater than 30% decrease in sum of diameters at mean follow up time of 88 days. Further studies of this and other cohorts is necessary to better understand the impact of PEF on metastatic disease to the lung.