Focal Therapy of Prostate Cancer Index Lesion With Irreversible Electroporation. A Prospective Study With a Median Follow-up of 3 Years

Abstract

Purpose: Our aim was to assess oncologic, safety, and quality of life-related outcomes of focal therapy with irreversible electroporation in men with localized prostate cancer.

Materials and methods: This was a single-center, phase II study.

Inclusion criteria: prostate cancer International Society of Urological Pathology grade 1-2, prostate specific antigen ≤15 ng/ml, ≤cT2b. Patients were selected based on multiparametric magnetic resonance imaging and transperineal systematic and targeted magnetic resonance imaging-ultrasound fusion-guided biopsy. Ablation of index lesions with safety margin was performed. Primary end point was cancer control, defined as the absence of any biopsy-proven tumor. A control transperineal biopsy was planned at 12 months and when suspected based on prostate specific antigen and/or multiparametric magnetic resonance imaging information. Quality of life was assessed using Expanded Prostate Cancer Index Composite Urinary Continence domain, International Index of Erectile Function, and International Prostate Symptom Score.

Results: From November 2014 to July 2021, 41 consecutive patients were included with a median follow-up of 36 months. Thirty patients (73%) had International Society of Urological Pathology grade 1 tumors, 10 (24%) grade 2, and 1 (2.4%) grade 3. Recurrence was observed in 16 of 41 (39%) of the whole cohort, and 16 of 33 (48.4%) who underwent biopsy. In-field recurrence was detected in 5 (15%) and out-of-field in 11 (33.3%). Ten of 41 (24.6%) including 3 of 5 (60%) with in-field recurrences had significant tumors (Gleason pattern 4-5; more than 1 core or any >5 mm involved). Median recurrence-free survival was 32 months (95% CI 6.7-57.2). Twenty-six patients (63.4%) were free from salvage treatment. All patients preserved urinary continence. Potency was maintained in 91.8%.

Conclusions: Irreversible electroporation can achieve satisfactory 3-year in-field tumor control with excellent quality of life results in selected patients.

Keywords: electroporation; image-guided biopsy; multiparametric magnetic resonance imaging; prostatic neoplasms.