General anesthesia and contrast-enhanced computed tomography to optimize renal percutaneous radiofrequency ablation: Multi-institutional intermediate-term results

Introduction: Percutaneous renal ablation is often performed under conscious sedation and without contrast-enhanced imaging. We evaluated intermediate-term outcomes of patients undergoing percutaneous contrast-enhanced computed tomography (CT)-guided radiofrequency ablation (RFA) under general anesthesia (GA) at two high-volume centers. Materials and Methods: Prospectively maintained Institutional Regulatory Board-approved databases were searched to identify patients treated with percutaneous RFA using contrast-enhanced CT under GA. A total of 163 masses in 151 patients were treated. Enhancement on imaging or a positive biopsy at 4 to 6 weeks was considered incomplete ablation. Positive findings beyond this interval were defined as local recurrence. Results: The median follow-up was 18 months (range, 1.5-70). Median tumor size was 2.3 cm (range, 1-5.4). Of the 130 (80%) masses with definitive pathology, 70% were renal cell cancer. Five masses had evidence of viable tumor at 4 to 6 weeks posttreatment for a complete initial ablation rate of 97%. Three of these five lesions were endophytic. Five masses (3.3%) showed evidence of local recurrence, and metastases developed in two patients (1.3%). Overall 1- and 3-year recurrence-free survival was 97% and 92%, respectively. Masses that were in the central region and were endophytic had the highest risk for recurrence (hazard ratio, 6.3; p=0.016). Conclusions: Intermediate-term outcomes of percutaneous RFA are excellent. GA-assisted, contrast-enhanced CT-guided percutaneous RFA demonstrates a high initial ablation success rate. However, endophytic and interpolar lesions are at higher risk for recurrence.