Central and deep renal tumors can be effectively ablated: radiofrequency ablation outcomes with fiberoptic peripheral temperature monitoring.

Background And Purpose: The "overtreatment" of incidental renal lesions with nephrectomy and a desire to reduce patient morbidity and preserve renal function resulted in the development of nephron-sparing surgical alternatives. As clinical experience accumulates with radiofrequency ablation (RFA), confidence in the oncologic effectiveness of the management method increases. Although many investigators describe RFA management success in small-to medium-sized renal tumors, hesitation is expressed when managing endophytic, central, or hilar lesions. Using RFA combined with peripheral real-time temperature monitoring, we have improved the management success rate for endophytic or centrally located renal masses.

Patients And Methods: RFA was selected in small-to medium-sized (range 1.0-5.3 cm), solid, contrast-enhancing, renal masses. CT-RFA appropriate tumors were accessible percutaneously through the flank in a prone position in the CT gantry. Anterior tumors, in close proximity (2 cm) to an abdominal viscus or other vital structure, underwent laparoscopic radiofrequency ablation (Lap-RFA). Fiberoptic temperature monitors (400 microm) were placed percutaneously 5 mm beyond the tumor periphery. Irrespective of lesion size, depth, or location, RFA treatments were continued until all peripheral sensors registered higher than 60 degrees C.

Results: In 131 patients, 146 tumors were managed with RFA ablation at our institution; 41 (28%) tumors in 39 patients were classified as endophytic. The mean endophytic tumor size was 2.7 cm (range 1.0-5.0 cm). Mean follow-up was 29 months. Thirty-seven of 41 (90.2%) endophytic, hilar, or centrally located tumors were managed with a single RFA procedure. Two of four recurrences were managed with extirpative therapy. Two recurrences await repeat CT-RFA management.

Conclusions: RFA with peripheral fiberoptic temperature monitoring provides a definitive management end point. Inadequate coverage of the tumor volume is immediately recognized in real time, which allows necessary treatment adjustments to be made. "Enhanced" RFA with peripheral temperature monitoring resulted in an improved single treatment success rate and boosted operator confidence in the management of endophytic, central, or hilar renal tumors.