Presentation Authors: Ryan Steinberg*, Brett Johnson, Jeffrey Cadeddu, Dallas, TX
Introduction: Irreversible electroporation (IRE) is an emerging ablative technology that applies high voltage, short pulse electrical current to create cellular membrane nanopores and cause apoptosis. This is thought to improve on the thermal limitations of other ablative modalities. We report the oncologic outcomes of percutaneous IRE for small renal masses after 5 years.
Methods: A single institution retrospective review of cT1a renal masses patients treated with IRE from April 2013 through August 2018 was performed. Small, low complexity tumors were generally selected for IRE using the NanoKnife&[copy] System (Angiodynamics, Latham, NY). Renal mass biopsy was obtained prior to or during ablation in most circumstances. Biopsy was excluded at ablation in some patients due to clinician concern IRE probe displacement. Post-ablation guideline-based surveillance imaging was performed. Survival analysis was performed via the Kaplan-Meier method.
Results: IRE was performed on 45 tumors in 44 patients. Mean tumor size was 2.0 Â± 0.6 cm with a median nephrometry score of 5 (Table 1). Thirty-one (69%) tumors were biopsied either pre-procedure or intraoperatively and 26 (58%) confirmed malignancy. Thirty-three patients (73%) were post-procedure same day discharges. No Clavien Grade III or higher intraoperative or post-operative complications occurred. Initial treatment success rate was 94%. Three initial treatment failures (6%) underwent successful salvage radiofrequency ablation. With 24-month median follow-up, three-year local recurrence-free survival was 85% in biopsy confirmed renal cell carcinoma (RCC) patients and 90% in all patients (Figure 1). Three-year overall survival was 100% in RCC confirmed patients and 97% in all patients. There were no RCC related deaths.
Conclusions: IRE has low morbidity and reasonable moderate-term oncologic results in small, low complexity tumors. Larger series and longer follow-up in a more heterogeneous cohort is needed to evaluate treatment durability.