Long-term oncologic outcomes following radiofrequency ablation with real-time temperature monitoring for T1a renal cell cancer.

OBJECTIVE: Few studies report long-term follow-up of renal cancer treated by radiofrequency ablation (RFA), thus limiting the comparison of this modality to well-established long-term follow-up series of surgically resected renal masses. Herein, we report long-term oncologic outcomes of renal cancer treated with RFA in a single institution. METHODS AND MATERIALS: We retrospectively reviewed patients treated between November 2001 and October 2012 with laparoscopic-guided or computed tomography-guided RFA. All treatments were performed with real-time thermometry ensuring target ablation temperature (>60°C) was adequately reached. Only patients with biopsy-confirmed T1a-category cancer and a follow-up period>48 months were included in our analysis. Follow-up included office visits, laboratory work, and periodic contrast-enhanced imaging. Survival was calculated using the Kaplan-Meier analysis. Overall complications were reported using the Clavien-Dindo scale. RESULTS: Of 434 RFA cases, 53 treatments in 50 patients met the inclusion criteria. Of these, 29 were treated with computed tomography-guided RFA and 24 with laparoscopic-guided RFA. The mean follow-up interval was 65.6 months (48.5-120.2), and the mean renal mass size was 2.3 cm (0.3-4.0). There were 4 (7.5%) local recurrences and 1 case of distant metastases with no local recurrence. The 5-year overall survival was 98%, cancer-specific survival was 100%, and recurrence-free survival was 92.5%. The complication rate was 26.4%, which included 71% of Clavien-Dindo grade I and 29% of grade II. Mean estimated glomerular filtration rate preoperatively and at the most recent follow-up visit was 77 and 66 ml/min, respectively. CONCLUSIONS: When performed on selected patients, while monitoring real-time temperatures to ensure adequate treatment end points, RFA offers favorable long-term oncologic outcomes approaching those reported for partial nephrectomy.

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

BACKGROUND AND PURPOSE: 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. PATIENTS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.