Histopathological outcomes after irreversible electroporation in prostate cancer; Results of an ablate-and-resect study

PURPOSE - Irreversible electroporation (IRE) is a tissue ablation modality that uses high-voltage electric energy to induce an increase of cell membrane permeability. This causes a destabilization of the existing cellular transmembrane potential leading to cell death, due to the inability to maintain cellular homeostasis.

This phase I-II study was designed to evaluate the histopathological outcomes of IRE to prostate and surrounding tissue in radical prostatectomy (RP) specimens.

MATERIALS AND METHODS - Sixteen prostate cancer patients underwent an IRE ablation without curative intent, followed by a RP scheduled four weeks later. For histopathological examination of the prostate, whole-mounted tissue slices were examined by dedicated genitourinary pathologists. The borders of the ablation zone and residual tumour were outlined on the slides.

RESULTS - The IRE ablation zones were characterized as areas of fibrosis, necrosis and loss of epithelial tissue in terms of denudation in the glandular structures. The ablation zone was well demarcated, showing trenchant delineations between the viable and non-viable tissue. The ablated tissue showed mild to moderate inflammation, with atrophic cells in one case. The area was surrounded by haemorrhage at the location of the electrodes. No skip lesions, no viable tissue, were seen within the ablation zone. Fibrinoid necrosis of the neurovascular bundle was observed in 13 patients and denudation of the urothelium of the prostatic urethra in 9 patients.

CONCLUSIONS - Histopathological assessment of the prostate four weeks after IRE ablation showed sharp-demarcated fibrotic and necrotic tissue within the ablation zone. No viable tissue was observed within the IRE ablation zone.

The Journal of urology. 2016 Mar 19 [Epub ahead of print]

W van den Bos, R R Jurhill, D M de Bruin, C D Savci-Heijink, A W Postema, P G K Wagstaff, B G Muller, I M Varkarakis, A Skolarikos, P J Zondervan, M P Laguna Pes, T M de Reijke, J J M C H de la Rosette

Dept. of Urology. Academic Medical Center, University of Amsterdam, the Netherlands. Dept. of Pathology. Academic Medical Center, University of Amsterdam, the Netherlands., Dept. of Urology. Academic Medical Center, University of Amsterdam, the Netherlands; Dept. of Biomedical Engineering & Physics, Academic Medical Center, University of Amsterdam, the Netherlands., Dept. of Pathology. Academic Medical Center, University of Amsterdam, the Netherlands., Dept. of Urology. Academic Medical Center, University of Amsterdam, the Netherlands., Dept. of Urology. Academic Medical Center, University of Amsterdam, the Netherlands., Dept. of Urology. Academic Medical Center, University of Amsterdam, the Netherlands., 2nd Dept. of Urology, Athens Medical University, University of Athens, Greece., 2nd Dept. of Urology, Athens Medical University, University of Athens, Greece., Dept. of Urology. Academic Medical Center, University of Amsterdam, the Netherlands., Dept. of Urology. Academic Medical Center, University of Amsterdam, the Netherlands., Dept. of Urology. Academic Medical Center, University of Amsterdam, the Netherlands., Dept. of Urology. Academic Medical Center, University of Amsterdam, the Netherlands.