Irreversible Electroporation for the Treatment of Small Renal Masses: 5-Year Outcomes.

INTRODUCTION Irreversible electroporation (IRE) is a nonthermal ablative technology that applies high voltage, short pulse electrical current to create cellular membrane nanopores and ultimately results in apoptosis. This is thought to overcome thermal limitations of other ablative technologies. We report 5-year oncologic outcomes of percutaneous IRE for small renal masses. PATIENTS AND METHODS A single-institution retrospective review of cT1a renal masses treated with IRE from 4/2013 - 12/2019 was performed. Those with <1 month follow up were excluded. IRE was performed with the NanoKnife© System (Angiodynamics, Latham, NY). Renal mass biopsy was obtained prior to or during ablation in most circumstances; biopsy was excluded in some patients due to concern for IRE probe displacement. Post-ablation guideline-based surveillance imaging was performed. Initial treatment failure was defined as persistent tumor enhancement on first post-treatment imaging. Survival analysis was performed via the Kaplan-Meier method for successfully treated tumors (SPSS; IBM, Armonk, NY). RESULTS IRE was used to treat 48 tumors in 47 patients. 22/48 tumors (45.8%) were biopsy-confirmed renal cell carcinoma (RCC). No complications ≥ Clavien Grade III occurred and 36 patients (76.6%) were discharged the same day. Initial treatment success rate was 91.7% (n=44/48); 3 treatment failures were managed with salvage radiofrequency ablation and 1 with robotic partial nephrectomy. Median follow up was 50.4-months (IQR 29.0-65.5). The 5-year local recurrence-free survival was 81.4% in biopsy-confirmed RCC patients and 81.0% in all patients. 5-year metastasis-free survival was 93.3% and 97.1%, respectively, and 5-year overall survival was 92.3% and 90.6%, respectively. 5-year cancer-specific survival was 100% for both biopsy-confirmed RCC and all patient groups. CONCLUSIONS IRE has low morbidity, but suboptimal intermediate-term oncologic outcomes compared to conventional thermal ablation techniques for small, low complexity tumors. Use of IRE should be restricted to select cases.

[1]  D. D. de Bruin,et al.  Feasibility and safety of irreversible electroporation (IRE) in patients with small renal masses: Results of a prospective study. , 2019, Urologic oncology.

[2]  J. Köllermann,et al.  Initial Assessment of the Efficacy of Irreversible Electroporation in the Focal Treatment of Localized Renal Cell Carcinoma With Delayed-interval Kidney Tumor Resection (Irreversible Electroporation of Kidney Tumors Before Partial Nephrectomy [IRENE] Trial-An Ablate-and-Resect Pilot Study). , 2018, Urology.

[3]  Jeffrey A. Cadeddu,et al.  Adult Urology Oncology : Adrenal / Renal / Upper Tract / Bladder lized Renal Cancer : AUA Guideline , 2017 .

[4]  J. Cadeddu,et al.  Irreversible electroporation of small renal masses: suboptimal oncologic efficacy in an early series , 2017, World Journal of Urology.

[5]  M. Allaf,et al.  Active surveillance is superior to radical nephrectomy and equivalent to partial nephrectomy for preserving renal function in patients with small renal masses: Results from the DISSRM registry. , 2017, Urologic oncology.

[6]  J. Cadeddu,et al.  Minimally Invasive Percutaneous Treatment of Small Renal Tumors with Irreversible Electroporation: A Single-Center Experience. , 2015, Journal of vascular and interventional radiology : JVIR.

[7]  J. Cadeddu,et al.  Long‐term outcomes in healthy adults after radiofrequency ablation of T1a renal tumours , 2014, BJU international.

[8]  D. Breen,et al.  Percutaneous cryoablation of renal tumours: outcomes from 171 tumours in 147 patients , 2013, BJU international.

[9]  S. Psutka,et al.  Long-term oncologic outcomes after radiofrequency ablation for T1 renal cell carcinoma. , 2013, European urology.

[10]  Stephen B. Solomon,et al.  The delayed effects of irreversible electroporation ablation on nerves , 2013, European Radiology.

[11]  Markus Porsch,et al.  Urinary Tract Effects After Multifocal Nonthermal Irreversible Electroporation of the Kidney: Acute and Chronic Monitoring by Magnetic Resonance Imaging, Intravenous Urography and Urinary Cytology , 2012, CardioVascular and Interventional Radiology.

[12]  Chad R. Tracy,et al.  Irreversible electroporation (IRE): a novel method for renal tissue ablation , 2011, BJU international.

[13]  Helen Kavnoudias,et al.  Investigation of the safety of irreversible electroporation in humans. , 2011, Journal of vascular and interventional radiology : JVIR.

[14]  Jens Ricke,et al.  Irreversible Electroporation of Renal Cell Carcinoma: A First-in-Man Phase I Clinical Study , 2011, CardioVascular and Interventional Radiology.

[15]  Brett A. Johnson,et al.  Ten-Year Outcomes of Renal Tumor Radio Frequency Ablation. , 2019, The Journal of urology.

[16]  F. Montorsi,et al.  Long-term oncologic outcomes of laparoscopic renal cryoablation as primary treatment for small renal masses. , 2015, Urologic oncology.