Feasibility and safety of focal irreversible electroporation as salvage treatment for localized radio-recurrent prostate cancer

To evaluate the feasibility, safety, early quality of life (QoL) and oncological outcomes of salvage focal irreversible electroporation (IRE) for radio-recurrent prostate cancer (PCa).

Patients with localized, radio-recurrent PCa without evidence of metastatic or nodal disease were offered focal IRE following the consensus guidelines. Patients with a minimum follow-up of 6 months were eligible for analysis. Adverse events were monitored using the NCI Common Terminology Criteria for Adverse Events (CTCAE version 4.0). Patient-reported QoL data was collected at baseline, 6 weeks, 3, 6 and 12 months using the Expanded Prostate Cancer Index Composite (EPIC), AUA symptom score and SF-12 Physical and Mental Component Summary (SF12-physical/SF12-mental) questionnaires. Oncological control was evaluated with serial prostate-specific antigen (PSA), 6-months multiparametric MRI (mpMRI) and 12-months prostate biopsy. Wilcoxon's Signed Rank Test was used to assess QoL differences over time in paired continuous variables.

A total of 18 patients were included for analysis. The median follow-up was 21 months. No high-grade adverse events (CTCAE >2) or recto-urethral fistula occurred. There were no statistically significant declines observed in QoL outcomes (n=11) on the EPIC Bowel domain (p=0.29), AUA symptom score (p=0.77), SF12-physical (p=0.17) and SF12-mental (p=0.77) questionnaires. At 6 months salvage patients experienced a decline in EPIC sexual domain (median of 38 to 24, p=0.028) and urinary domain (median of 96 to 92, p=0.074). Pad-free continence and erections sufficient for intercourse were preserved in 73% (n=8/11) and 33% (n=2/6) at 6 months, respectively. The mpMRI was clear in 85% (n=11/13), with two single out-field lesions (true-positive and false-positive, respectively). Median nadir PSA was 0.39 μg/L (IQR 0.04-0.43). A total of 3 (17%) and 4 (22%) patients experienced biochemical failure using the Phoenix and Stuttgart definitions of biochemical failure, respectively. 80% (n=8/10) of the patients were clear of any PCa on follow-up biopsy, whereas 2 patients had significant PCa on follow-up biopsy (ISUP 5).

Our short-term safety, QoL and oncological control data demonstrate that focal IRE is a feasible salvage option for localized radio-recurrent PCa. A prospective multi-centre study (FIRE-trial) has been initiated that will provide further insight in the ability of focal IRE to obtain oncological control of radio-recurrent PCa with acceptable patient morbidity. This article is protected by copyright. All rights reserved.

BJU international. 2017 Aug 21 [Epub ahead of print]

Matthijs J Scheltema, Willemien van den Bos, Amila R Siriwardana, Anton M F Kalsbeek, James E Thompson, Francis Ting, Maret Böhm, Anne-Maree Haynes, Ron Shnier, Warick Delprado, Phillip D Stricker

Garvan Institute of Medical Research & The Kinghorn Cancer Centre, Darlinghurst, NSW, Australia., St Vincent's Prostate Cancer Centre, Darlinghurst, NSW, Australia., Southern Radiology, Randwick, NSW, Australia., Douglass Hanly Moir Pathology, Macquarie Park, NSW, Australia.