High-power radiofrequency ablation with optimized pulsing algorithm for renal tumors: initial clinical experience and safety profile

Incidental diagnosis of renal cell carcinoma is increasing. While surgery remains the standard treatment for localized T1b or larger lesions, image-guided percutaneous ablation represents a valid alternative for T1a cases. Radiofrequency ablation (RFA) is effective but limited by smaller ablation volumes and sensitivity to the heat-sink effect. Microwave ablation and cryoablation have emerged to address these limitations, although the first is susceptible to thermal injury to adjacent structures and the second requires multiple, larger probes and longer procedures. High-power RFA (HP-RFA) is a recent development that delivers higher energy (370 versus 200 W), enabling faster and larger ablations. This study evaluated the feasibility and safety of a novel HP-RFA system incorporating an impedance-controlled pulsed algorithm and internally cooled electrodes. Five patients with small renal tumors (mean diameter 2.3 cm) unsuitable for surgery underwent ultrasound- or computed tomography-guided HP-RFA. Technical success, safety, and early tumor control were assessed. All procedures were technically successful. No major complications occurred; one minor perirenal hematoma was managed conservatively. Follow-up imaging at 6 months demonstrated complete tumor ablation without local recurrence. These preliminary findings suggest that HP-RFA is feasible and safe for treating small renal tumors and may represent a promising evolution of RFA. Further studies are needed. KEY POINTS: Question Can HP-RFA provide feasible and safe minimally invasive treatment for small renal tumors while overcoming limitations of conventional RFA? Findings Technical success and efficacy of HP-RFA were achieved in 100% of cases. No major complications. Complete tumor ablation was accomplished. Relevance statement HP-RFA demonstrates feasibility, safety, and effective early tumor control in small renal tumors. By enabling larger, faster ablations, it may overcome limitations of conventional RFA and expand the employment of minimally invasive treatment options instead of surgical approaches.