Limited Effectiveness in Early Human Clinical Experience with Pulsed Electrical Field Ablation

To evaluate oncological outcomes, abscopal effect, and adverse events (AEs) of pulsed electrical field (PEF) ablation of tumors in the chest, abdomen, and pelvis.

PEF ablations performed at an academic medical center between May 2023 and January 2024 were retrospectively analyzed. Eleven patients (4 males and 7 females; age, 58 years ± 19) underwent 11 PEF sessions targeting 13 tumors (lung metastasis from solitary fibrous tumor [n = 3] and colorectal carcinoma (CA) [n = 1], osteosarcoma pleural metastases [n = 2], hepatocellular CA [n = 2], liver metastasis from colorectal CA [n = 1] and leiomyosarcoma [n = 1], metastatic melanoma to the pancreas [n = 1], metastatic retroperitoneal lymph node from endometrial CA [n = 1], and recurrence of endometrial CA in the vaginal cuff [n = 1]) with the goal of complete coverage (n = 11/13) or debulking (n = 2/13). The mean tumor diameter was 1.9 cm (SD ± 1.0; range, 0.4-3.3 cm). Cross-sectional imaging follow-up was 5.3 months (SD ± 2.2; range, 1.9-7.9 months). Oncological outcomes, abscopal effect, and AEs categorized according to the Society of Interventional Radiology (SIR) guidelines were analyzed.

Of 11 tumors that underwent ablation for complete coverage, complete coverage was achieved for 1 (9%), and residual was detected in 9 (81%). Ten (91%) of 11 patients showed either residual, local, or distant progression within a median of 3 months. No abscopal effect was observed. There were 2 mild and 2 severe AEs.

PEF ablation showed a low rate of complete coverage (9%) and a high rate (91%) of residual, local, or distant progression. No abscopal effect was observed in any patient within a median of 5.1 months after the ablation.