3:27 PM Abstract No. 243 Microwave ablation vs cryoablation in the treatment of T1a renal cell carcinoma: a single-center comparison of safety and outcomes

Abstract

To compare the safety and efficacy of percutaneous ablation of T1a renal cell carcinoma (RCC) performed utilizing microwave ablation (MWA) and cryoablation (CRYO). Retrospective analysis spanning 9/2006 to 9/2014 was performed to identify RCC patients treated with MWA or CRYO. 37 patients with RCC underwent 40 percutaneous ablation procedures during the study period. 22 CRYO procedures (mean tumor diameter: 2.6 ± 0.9 cm, mean RENAL score: 7.3 [range 4-10], mean PRAC score: 8.3 [range 4-11.5]) were performed for 20 patients (age: 69.9 ± 8.1 years, male sex: 65%). 18 MWA procedures (mean tumor diameter: 2.4 ± 0.8 cm, mean RENAL score: 7.2 [range 4-10], mean PRAC score: 7.7 [range 4-11.5]) were performed for 18 patients (age: 66.8 ± 12.8 years, male sex: 61.1%). Outcomes variables included technical success, pre- and posttreatment lab values, complications, imaging response, and overall survival. Technical success was achieved in all cases. There was no significant difference in baseline renal function between MWA (BUN: 19.6 ± 7.2 mg/dl, creatinine: 1.4 ± 0.8 mg/dl) and CRYO (BUN: 24.6 ± 16.0 mg/dl, creatinine: 1.2 ± 0.5 mg/dl) groups (p = 0.238 and p = 0.465 respectively) or significant change in either BUN post-ablation for MWA and CRYO (p = 0.852 and p = 0.805 respectively) or creatinine (p = 0.355 and p = 0.599 respectively). There were 7 complications (MWA:5, Cryo:2) including 6 perinephric hematomas and an episode of urinary retention, 2 being major (SIR C) complications, without significant difference in the complication incidence between the 2 groups (p = 0.259). At median follow-up time of 3.2 years, 7 instances of disease progression (Cryo:5, MWA: 2) occurred at an average of 14.7 months post-ablation with no difference in disease progression between modalities (p = 0.205). Overall cohort survival was 5.1 (95% CI: 4.3–6.0) years with no significant difference between treatment groups (p = 0.486). There is no difference in technical success, renal function change, complication incidence, imaging outcomes, or overall survival in RCC patients treated with either microwave ablation or cryoablation. Overall survival in the present cohort was 5.1 (95% CI: 4.3–6.0) years.