Second prize: Recurrence rates after percutaneous and laparoscopic renal cryoablation of small renal masses: does the...

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.

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.

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.

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.