Percutaneous cryoablation of stage T1b renal cell carcinoma: Technique considerations, safety, and local tumor control

Purpose To describe the technical methods, safety, and local tumor control rate associated with percutaneous cryoablation of stage T1b renal cell carcinoma (RCC). Materials and Methods A retrospective review of a percutaneous renal ablation registry was used to identify 46 patients with a total of 46 biopsy-proven RCC lesions measuring 4.1-7.0 cm treated with cryoablation between 2003 and 2011. The main outcome parameters investigated were adjunctive maneuvers, complications, and local tumor progression, and cancer-specific survival rates. Complication rates were categorized and recorded using the Clavien-Dindo classification system. Progression-free and cancer-specific survival rates were estimated using the Kaplan-Meier method. Results The mean treated RCC size was 4.8 cm (range, 4.1-6.4 cm). Prophylactic tumor embolization was performed in 7 patients (15%), ipsilateral ureteral stents were placed in 7 patients (15%), and hydrodisplacement of bowel was performed in the treatment of 16 tumors (35%). A single technical failure (2.2%) was observed at the time of ablation. Thirty-six tumors (78%) had follow-up imaging at 3 months or later following ablation, including a single recurrence at 9 months after ablation. The mean duration of follow-up for the 35 RCC tumors that did not recur was 2.0 years (range, 0.3-6.1 y). Estimated local progression-free survival rate at 3 years was 96.4%. Of the 46 cryoablation procedures, there were 7 complications (15.2%) of grade II or worse. Conclusions The results suggest that cryoablation represents a valid treatment alternative for select patients with clinical stage T1b RCC. Complications are frequent enough that multidisciplinary patient management should be considered.