EAU 2020: Midterm Oncological Results of Focal Therapy: Irreversible Electroporation Focal Ablation

(UroToday.com) At the European Association of Urology (EAU) Virtual 2020 meeting, the focal therapy for prostate cancer thematic session featured a discussion on irreversible electroporation focal ablation by Phillip Stricker, MBBS, FACS, from Sydney, Australia. His inclusion criteria for irreversible electroporation focal ablation are typically as follows:

  • Primary treatment: generally unilateral GG2 or favorable GG3
  • Salvage treatment: treat unilateral/focal recurrence, any Gleason score
  • Unilateral tumor: only treat unilateral clinically significant prostate cancer; contralateral small foci of GG1 is accepted for the treatment of the index lesion
  • Multi-parametric magnetic resonance imaging (mpMRI): predominantly only treat mpMRI visible disease, otherwise perform quadrant or hemiablation
  • Location: can treat any segment of the prostate
  • Distance of the tumor to the apex: place electrodes 3 mm from the apex

Irreversible electroporation involves non-thermal ablation delivering high-voltage electric current between transperineal electrodes. A catheter is placed prior to treatment and is removed between day 2-4 post-treatment depending on pre-treatment lower urinary tract symptoms. In situations where there is a mpMRI-visible lesion, 10 mm of coverage is added to the edge of the lesion. Dr. Stricker monitors patients with a PSA every 3 months for the first year and a mpMRI after six months post-treatment. Per-protocol, at one year Dr. Stricker performs a systematic transperineal biopsy plus targeted biopsies as needed (4-6 cores).

At Dr. Stricker’s institution, 210 patients have been treated as their primary treatment. The median age was 68 years of age (interquartile range (IQR) 61-73), most patients were GG2 (76%), median prostate volume was 40 cc (IQR 30-60). The remaining patient characteristics are as follows:

PatientCharacteristics_FocalTherapy_EAU2020.png

23% of patients had Clavien-Dindo Grade I complications, most commonly perineal pain, hematuria, dysuria, urgency and frequency. There were no Grade III-V complications. Furthermore, 93% of patients retained potency and 98.8% of men were pad free at 12 months. The median PSA nadir was 3.3 ng/mL (IQR 1.2-5.4) and on follow-up biopsies, 6% had in-field residual disease and 14% out of field disease. Overall, 24 patients had redo irreversible electroporation focal ablation and failure-free survival at 3 years was 96.8%. Although with limited follow-up (median 14 months), 16 patients have undergoing salvage robotic prostatectomy after irreversible electroporation focal ablation with no biochemical recurrences.

Presented by: Phillip D. Stricker, MBBS, FACS, University of NSW, Garvan Institute of Medical Research/Kinghorn Cancer Centre, Sydney, Australia

Written by: Zachary Klaassen, MD, MSc – Assistant Professor of Urology, Georgia Cancer Center, Augusta University/Medical College of Georgia, Augusta, GA, USA, Twitter: @zklaassen_md at the Virtual 2020 EAU Annual Meeting #EAU20, July 17-19, 2020