Oncologic outcomes using real-time peripheral thermometry-guided radiofrequency ablation of small renal masses

With the increased incidence of low-stage renal cancers, thermal ablation technology has emerged as a viable treatment option for extirpation in selected persons and is supported by the current American Urological Association guidelines. We present a 9-year, single institution experience with radiofrequency ablation (RFA) using real-time peripheral temperature monitoring of small renal masses focusing on oncologic outcomes.

We reviewed our prospectively collected database of patients with renal masses who were treated between November 2001 and January 2011 with laparoscopic (LRFA) or CT-guided percutaneous RFA (CTRFA) with simultaneous real-time peripheral fiberoptic thermometry. Patients were followed radiographically at 1 month, 6 months, 1 year, and then annually. Clinicopathologic outcomes were collected and analyzed.

A total of 274 patients (211 male) aged 18 to 88 years (mean 67 years) with 292 renal tumors underwent LRFA (112) or CTRFA (180). Mean tumor size was 2.5 cm (0.7-5.3 cm). An intraoperative preablation biopsy showed 197 (67.4%) renal-cell carcinomas (RCC), and 77 (26.4%) benign tumors. Mean follow-up was 26 months (1-98 mos). The single ablation treatment radiographic success rate was 96% for all tumors and 94% for RCC. Metastatic RCC developed in one patient, who died. The Kaplan-Meier (KM) 3-year and 5-year cancer-specific survival was 100% and 98.6%, respectively. The KM 3-year and 5-year overall survival was 90.4% and 74.2%, respectively.

RFA is a clinically effective and safe nephron-sparing treatment of patients with small renal masses. Our large cohort and intermediate-term experience adds to the building evidence for the efficacy of RFA for small renal cancers.