MulticentRe rEal World outcomes of IrReversible Electroporation for complex small kiDney cancers (REWIRED)

Purpose

Image-guided ablation (IGA) of central, endophytic and hilar tumours close to vital structures remains a major clinical challenge. This study evaluates real-world outcomes of irreversible electroporation (IRE) for small renal mass (RCCs) deemed unsuitable for surgery or conventional thermal ablation.

Material and methods

This retrospective analysis utilised a prospectively maintained database from three specialist centres (USA, UK, Spain) for patients undergoing percutaneous IRE (NanoKnife® 3.0 System, Angiodynamics) for biopsy-proven RCC between May 2015 and October 2024. Patients were selected via multidisciplinary team discussion, typically due to tumour proximity to vital structures, solitary kidneys, significant comorbidities, or prior interventions.

Results

68 patients (mean age 66.9 years; SD 12.3) with 71 tumours were included. Mean tumour size was 2.83 cm (SD 1.39) and median RENAL Nephrometry score was 9 (IQR 6–9). Primary technique efficacy was 77.5% (55/71), with a local control rate of 95.8% (68/71). Technical success rate was 100%. Two major adverse events (2.8%; ureteric injury and haematuria) were observed. Mean eGFR change was -7.5 ml/min/1.73m2, with 10.0% of cases seeing a > 25% reduction. At 59-month mean follow-up (SD 35), 5-year Local Tumour Progression-Free Survival was 84.4% (95% CI 71.8–91.7%). The trifecta outcome (primary efficacy, no major adverse events, and < 25% eGFR decline) was achieved in 68.6% of cases.

Conclusion

According to the results of the current study, IRE is safe and effective in managing tumours near vital structures that are unsuitable for surgery or other ablation modalities. Further studies comparing IRE to other modalities are warranted.

Level of Evidence

Level 4, Case Series