Percutaneous cryoablation of renal masses: impact of patient selection and treatment parameters on outcomes.

Objectives: To evaluate whether the trend in patient selection or perioperative parameters were associated with treatment outcomes after percutaneous cryoablation (PCA) of renal masses.

Methods: We retrospectively analyzed our urological oncology database and identified 52 patients treated for a total of 54 renal masses. Univariate analysis was performed to evaluate whether the variables of age, gender, tumor size, number of probes used, total freezing time, preoperative creatinine, American Society of Anesthesia class, body mass index, or age-adjusted Charlson comorbidity index (CCI) score had an impact on the outcomes of treatment failure or the complication rate.

Results: During a mean follow-up of 21 months, recurrence-free, overall, and disease-specific (based on radiographic follow-up and biopsy) survival were 96.2%, 98.1% and 100%, respectively. The mean age-adjusted CCI score for patients with postoperative complications was 6.5, compared with a mean score of 3.0 in patients without postoperative complications (P = .02). The complication rate was also significantly higher when a greater number of cryoprobes were used during PCA (P < .005). None of the variables analyzed were predictive of treatment failure.

Conclusions: Of the pre- and intraoperative variables studied, age-adjusted CCI score and number of cryoprobes used were the only variables with predictive value for outcomes in regard to treatment failure or complications. As investigators continue using cryoablation to treat renal masses, it is important to be able to completely and honestly counsel patients regarding the likelihood of complications and need for subsequent therapy in the setting of treatment failure.