Feasibility and safety of irreversible electroporation (IRE) in patients with small renal masses: Results of a prospective study.

Irreversible electroporation (IRE) has the potential to overcome limitations of thermal ablation, enabling small renal mass (SRM) ablation near vital structures.

To assess feasibility and safety of percutaneous IRE for the treatment of SRMs.

This prospective study is a phase 2 trial (NCT02828709) of IRE for patients with SRMs. Primary endpoints are feasibility and safety. Device- and procedural-adverse events were assessed by Clavien-Dindo and Common Terminology Criteria for Adverse Events version 4.0 grading systems. Technical feasibility was assessed by recording the technical success of the procedures. Technical success was evaluated by performing a CT immediately after ablation where complete tumor coverage and nonenhancement were evaluated. Tumor charcateristics and patient characteristics, procedural and anesthesia details, postprocedural events, and perioperative complications were recorded.

Ten SRMs were included with a mean tumor size of 2.2 cm (range 1.1-3.9 cm) were treated with IRE. Renal mass biopsies revealed 7 clear cell and 1 papillary renal cell carcinoma. Two renal mass biopsies were nondiagnostic. The median follow-up was 6 months (range 3-12 months). Technical success was achieved in 9 out of 10 cases. One patient had a grade 3 Clavien-Dindo complication (1/10, 95% Confidence interval (CI) 0.0179-0.4041). Mean anesthesia time was 3.7 hours (range 3-5 hours), mean procedural time was 2.1 hours (range 1 hour 45 minutes-2 hours 30 minutes) and mean ablation time was 50 minutes (range 20 minutes-1 hour 45 minutes). The creatinine preoperative and postoperative (1 week, 3 months, 6 months, and 12 months) did not significantly differ. In total, 8 out of 10 cases did not experience postoperative pain.

IRE in SRMs is safe and feasible. Renal function is not affected by IRE and postoperative pain is rare. Anesthesia time and procedural time are a potential concern.

Urologic oncology. 2018 Nov 30 [Epub ahead of print]

Mara Buijs, Patricia J Zondervan, Daniel M de Bruin, Krijn P van Lienden, Axel Bex, Otto M van Delden

Department of Urology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands. Electronic address: ., Department of Urology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands., Department of Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, the Netherlands., Department of Radiology, Academic Medical Center, Amsterdam, the Netherlands., Department of Urology, The Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Amsterdam, the Netherlands.