Personalized Treatment Strategy in "Low-Risk Prostate Cancer Active Surveillance Candidates" Using Irreversible Electroporation: Prospective Evaluation of Feasibility, Morbidity, Functional and Oncological Outcomes.

Purpose: To evaluate the morbidity, functional and oncological outcome of irreversible electroporation (IRE) as a focal therapy for prostate cancer (PCa) when used in "active surveillance (AS)" candidates refusing standard treatment options.

Materials and methods: IRE was performed under general anaesthesia, and the transurethral catheter was removed one day after intervention in all patients. Pre- and post-interventional voiding parameters (measured by International Prostate Symptom Score Questionnaire [IPSS], uroflowmetry and post-void residue) were compared. Follow-up (FU) was observed over a minimum of six months, including oncological outcome (controlled by multiparametric magnetic resonance imaging, rebiopsy, prostate-specific antigen dynamic as well as the need and type of secondary treatment) and general functional outcome (International Index of Erectile Function Questionnaire, satisfaction of the procedure).

Results: Twenty-four patients refusing AS or standard treatment with a median FU of 18.7 months were included. IPSS showed nine patients with mild, 12 with moderate and two with severe obstructive voiding symptoms pre-intervention (focal IRE). Median IPSS pre-IRE was 9 points, 8.5 (p=0.341) at six months and 10 (p=0.392) after 12 months, respectively. Pre-IRE maximum urinary flow (Qmax) (median: 16.1±8.0 mL/sec) and Qmax after catheter removal (16.2±7.6 mL/sec) did not differ significantly (p=0.904). Thirteen PCa recurrences occurred (54.2%). Out-of-lesion-PCa was found in 12/13 patients (92.3%), while 4/13 patients showed in-lesion-PCa recurrence simultaneously (30.8%). In one patient, there was an in-lesion-PCa recurrence only (7.7%). Six out of 24 patients (25.0%) received a secondary treatment. All patients were satisfied with the IRE procedure.

Conclusions: Focal IRE underperforms regarding the overall oncological outcome and should not be offered as an equivalent therapy to established curative treatment strategies. Nevertheless, under a strict FU regimen, its lack of significant additional morbidity compared to an active surveillance strategy makes IRE a feasible alternative for low-risk PCa in highly selected patients as a personalised approach.