title: The correlation between the electrode configuration and histopathology of irreversible electroporation ablations in prostate cancer patients.
abstract: OBJECTIVE
  Irreversible electroporation (IRE) is a novel minimally invasive therapy for prostate cancer using short electric pulses to ablate prostate tissue. The purpose of this study is to determine the IRE effects in prostate tissue and correlate electrode configuration with the histology of radical prostatectomy (RP) specimens. We hypothesize that the area within the electrode configuration is completely ablated and that the area within the electrode configuration is predictive for the ablated area after treatment.
  
  
  METHODS
  A prospective phase I/II study was conducted in 16 consecutive patients with histopathologically confirmed prostate cancer scheduled for RP. Focal or extended IRE treatment of the prostate was performed 4 weeks prior to RP. The locations of the electrodes were used to calculate the planned ablation zone. Following RP, the specimens were processed into whole-mount sections, histopathology (PA) was assessed and ablation zones were delineated. The area of the tissue alteration was determined by measuring the surface. The planned and the histological ablation zones were compared, analysed per individual patient and per protocol (focal vs. extended).
  
  
  RESULTS
  All cells within the electrode configuration were completely ablated and consisted only of necrotic and fibrotic tissue without leaving any viable cells. The histological ablation zone was always larger than the electrodes configuration (2.9 times larger for the 3 electrodes configuration and 2.5 times larger for the ≥4 electrode configuration). These ablation effects extended beyond the prostatic capsule in the neurovascular bundle in 13 out of 15 cases.
  
  
  CONCLUSIONS
  IRE in prostate cancer results in completely ablated, sharply demarcated lesions with a histological ablation zone beyond the electrode configuration. No skip lesions were observed within the electrode configuration.
  
  
  RESULTS
  ClinicalTrials.gov Identifier: NCT01790451 https://clinicaltrials.gov/ct2/show/NCT01790451.
authors: Department of Urology Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. w.vandenbos@amc.uva.nl.
authors: W
authors: W
authors: van den Bos
authors: Department of Urology Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.|Department of Biomedical Engineering and Physics. Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors: D M
authors: DM
authors: de Bruin
authors: Department of Pathology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
authors: R R
authors: RR
authors: Jurhill
authors: Department of Pathology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
authors: C D
authors: CD
authors: Savci-Heijink
authors: Department of Urology Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors: B G
authors: BG
authors: Muller
authors: 2nd Department of Urology, Athens Medical University, University of Athens, Athens, Greece.
authors: I M
authors: IM
authors: Varkarakis
authors: 2nd Department of Urology, Athens Medical University, University of Athens, Athens, Greece.
authors: A
authors: A
authors: Skolarikos
authors: Department of Urology Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors: P J
authors: PJ
authors: Zondervan
authors: Department of Urology Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors: M P
authors: MP
authors: Laguna-Pes
authors: Department of Urology Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.|Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
authors: H
authors: H
authors: Wijkstra
authors: Department of Urology Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors: T M
authors: TM
authors: de Reijke
authors: Department of Urology Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors: J J M C H
authors: JJ
authors: de la Rosette
mesh_terms: D055011:Ablation Techniques; D000328:Adult; D000368:Aged; D004566:Electrodes; D018274:Electroporation; D004598:Electrosurgery / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000473:pathology* / Q000601:surgery*
keywords: Focal therapy; IRE; Irreversible electroporation; Planning; Prostate cancer