Second prize: Recurrence rates after percutaneous and laparoscopic renal cryoablation of small renal masses: does the approach make a difference?

BACKGROUND AND
PURPOSE: As radiologic detection of small renal masses increases, patients are increasingly offered percutaneous renal cryoablation (PRC) or transperitoneal laparoscopic renal cryoablation (TLRC). This multicenter experience compares these approaches. PATIENTS AND METHODS: Between September 1998 and May 2010, review of our PRC and TLRC experience was performed. Patients with ≥ 12-month follow-up were included for analysis. Post-treatment surveillance consisted of laboratory studies and imaging at regular intervals. Treatment failure was considered if persistent mass enhancement or interval tumor growth was radiographically evident. Repeated biopsy and re-treatment were recommended in the event of recurrence.
RESULTS: Sixty-one patients underwent PRC and 84 patients underwent TLRC. No significant differences were noted with respect to demographic factors. Mean tumor size was 2.7 ± 1.1 cm (PRC) and 2.5 ± 0.8 (TLRC) cm (P = 0.090). Mean follow-up was 31.0 ± 15.9 months (PRC) and 42.3 ± 21.2 (TLRC) months (P = 0.008), with local tumor recurrence noted in 10/61 (16.4%) PRC and 5/84 (5.9%) TLRC (P = 0.042). For PRC, disease-free survival (DFS) and overall survival (OS) were 93.7% and 88.9%, respectively, with four patients having evidence of disease at last follow-up. DFS and OS were 91.7% and 89.3% for TLRC, with seven patients having evidence of disease at last follow-up. DFS (P = 0.654) and OS (P = 0.939) were similar.
CONCLUSIONS: In this multicenter study of well-matched cohorts, PRC had higher primary treatment failure rates than TLRC. While no differences were noted between DFS and OS, analysis is limited by intermediate follow-up. Further study is necessary to discern reasons for the higher recurrence rates in PRC and to determine what long-term consequences exist.