Renal cryoablation of small renal masses: A Korea University experience

Purpose: To evaluate the perioperative, functional, and oncological outcomes of renal cryoablation (RC) of small renal masses (SRMs) performed in Korea University Hospital. Materials and Methods: We reviewed an Institutional Review Board-approved database of 70 patients who underwent RC and were followed up for a minimum of 3 months by a single surgeon in Korea University Hospital from August 2007 to May 2014. Among these patients, 68 patients (79 renal masses) were enrolled in our research. We evaluated perioperative, functional, and oncologic outcomes of RC. Results: A total of 68 patients (79 renal masses) underwent RC in our institution. The mean age of the patients was 62.0 years. The mean tumor size was 2.25 cm. Among the 59 patients who underwent laparoscopic surgery, only 1 patient (1.47%) was converted to open surgery. No other perioperative complications occurred. The mean preoperative and 1-month postoperative estimated glomerular filtration ratio (eGFR) were 71.8 and 68.3 mL/min/1.73 m(2), respectively (p = 0.19). The mean 1-year postoperative eGFR was 65.0 mL/min/1.73 m(2) (p = 0.25). The mean follow-up period was 59.76 months (range, 3-119 months). Local tumor recurrence occurred in eight tumors (15.4%; a total of 52 renal cell carcinomas). Concerning treatment in the patients with recurrence, five patients underwent re-treatment and three patients are under active surveillance. None of the eight patients who experienced local recurrence had additional recurrence or tumor progression during the follow-up period. In our study, the recurrence-free rate was 83.0% and the cancer-specific survival rate was 100%. Moreover, the 5-and 10-year overall survival rates were both 100%. Conclusions: Long-term experience with RC in our institution demonstrates that RC is a safe and effective treatment for patients with SRMs.