Median 5-year outcomes of primary focal irreversible electroporation for localised prostate cancer

Objectives: To evaluate longer-term oncological and functional outcomes of focal irreversible electroporation (IRE) as primary treatment for localised clinically significant prostate cancer (csPCa) at a median follow-up of 5 years (up to 10 years). Patients and Methods: All patients that underwent focal IRE as primary treatment for localised PCa between February 2013 and August 2021 with a minimum 12 months of follow-up were analysed. Follow-up included 6-month magnetic resonance imaging (MRI) and standardised transperineal saturation template ± targeted biopsies at 12 months, and further biopsies in the case of clinical suspicion on serial imaging and/or prostate-specific antigen (PSA) levels. Failure-free survival (FFS) was defined as no progression to radical treatment or nodal/distant disease. Local recurrence was defined as any International Society of Urological Pathology Grade of ≥2 on biopsy. Results: A total of 229 patients were analysed with a median (interquartile range [IQR]) follow-up of 60 (40–80) months. The median (IQR) age was 68 (64–74) years, the median (IQR) PSA level was 5.9 (4.1–8.2) ng/mL, and 86% harboured intermediate-risk disease and 7% high-risk disease. In all, 38 patients progressed to radical treatment (17%), at a median (IQR) of 35 (17–53) months after IRE. Kaplan–Meier FFS rates were 91% at 3 years, 84% at 5 years and 69% at 8 years. Metastasis-free survival was 99.6% (228/229), PCa-specific and overall survival were 100% (229/229). Residual csPCa was found in 24% (45/190) during follow-up biopsy and MRI showed a complete ablation in 82% (186/226). Short-term urinary continence was preserved (98%, three of 144 at baseline, 99%, one of 131 at 12 months) and erections sufficient for intercourse decreased by 13% compared to baseline (71% to 58%). Conclusion: Longer-term follow-up confirms our earlier findings that focal IRE provides acceptable local and distant oncological control in selected men with less urinary and sexual toxicity than radical treatment. Long-term follow-up and external validation of these findings, is required to establish this new treatment paradigm as a valid treatment option.