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

Abstract

Objectives 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 and Methods Patients with localized, radio‐recurrent PCa without evidence of metastatic or nodal disease were offered focal IRE according to the consensus guidelines. Patients with a minimum follow‐up of 6 months were eligible for analysis. Adverse events were monitored using the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE version 4.0). Patient‐reported QoL data were collected at baseline, 6 weeks, 3, 6 and 12 months using the Expanded Prostate Cancer Index Composite (EPIC), the American Urological Association (AUA) symptom score and the 12‐item short‐from health survey (SF‐12) physical and mental component summary questionnaires. Oncological control was evaluated according to serial prostate‐specific antigen (PSA), 6‐month multiparametric magnetic resonance imaging (mpMRI) and 12‐month prostate biopsy. Wilcoxon's signed rank test was used to assess QoL differences over time in paired continuous variables. Results A total of 18 patients were included in the analysis. The median follow‐up was 21 months. No high‐grade adverse events (CTCAE >2) or recto‐urethral fistulae occurred. No statistically significant declines were observed in QoL outcomes (n = 11) on the EPIC bowel domain (P = 0.29), AUA symptom score (P = 0.77), or the SF‐12 physical (P = 0.17) or SF‐12 mental component summary (P = 0.77) questionnaires. At 6 months, patients who had undergone salvage therapy experienced a decline in EPIC sexual domain score (median of 38–24; P = 0.028) and urinary domain (median of 96–92; P = 0.074). Pad‐free continence and erections sufficient for intercourse were preserved in 8/11 patients and 2/6 patients at 6 months, respectively. The mpMRI was clear in 11/13 patients, with two single out‐field lesions (true‐positive and false‐positive, respectively). The median (interquartile range) nadir PSA was 0.39 (0.04–0.43) μg/L. Three and four patients experienced biochemical failure using the Phoenix and Stuttgart definitions of biochemical failure, respectively. Eight out of 10 of the patients were clear of any PCa on follow‐up biopsy, whereas two patients had significant PCa on follow‐up biopsy (International Society of Urological Pathology grade 5). Conclusion Our short‐term safety, QoL and oncological control data show that focal IRE is a feasible salvage option for localized radio‐recurrent PCa. A prospective multicentre study (FIRE trial) has been initiated that will provide further insight into the ability of focal IRE to obtain oncological control of radio‐recurrent PCa with acceptable patient morbidity.

Irreversible electroporation (IRE): a narrative review of the development of IRE from the laboratory to a prostate cancer treatment

“…Another recent prospective cohort study of 30 patients, with a median follow-up of 20 months, reported similar oncological and function outcomes [32]. The results of studies applying IRE are shown in Table 2 [22][23][24][25][26][27][30][31][32]37,48].…”

A contemporary, nationwide analysis of surgery and radiotherapy treatment for prostate cancer

“…Increased use of EBRT has been observed in the USA, from 11.6% to 24% in the same period . Reasons for these trends may include changes in PSA testing, use of MRI and prostate biopsy, AS, robotic surgery and newer focal therapies (such as Cyberknife or irreversible electroporation ) that may be better clarified after further analysis with the maturation of the Prostate Cancer Outcomes Registry of Australia and New Zealand .…”

“Super-active surveillance”: MRI ultrasound fusion biopsy and ablation for less invasive management of prostate cancer

“…Following pretreatment imaging [currently performed with mpMRI or transperineal template mapping prostate biopsy (TTMP)], IRE is conducted with transperineal placement of probes under ultrasound guidance to establish an ablative field (86)(87)(88)(89). Presently, the NanoKnife platform (Angiodynamics, Queensbury, NY), is the only FDA 501(k) cleared IRE system, although it has limited clinical use thus far.…”

“…In a number of clinical studies (Table 4) followup consisted of an mpMRI with contrast 1-6 weeks after IRE, mpMRI at 6 months, and repeat biopsy at 6 months to 1 year. PSA was assayed at 3-month intervals (87)(88)(89). Occasionally, contrast-enhanced ultrasound (CEUS) was used for pre-treatment and post-treatment imaging (91,92).…”

“…Dysuria, urinary retention, and UTIs were also seen (86)(87)(88). In three clinical studies evaluating the use of IRE in primary and salvage scenarios, post-treatment continence rates ranged from 73-100% and potency rates ranged from 33-85% (87)(88)(89). The salvage IRE trial yielded the lowest results for continence and potency (89).…”