CIO 2022-22 Percutaneous Cryoablation versus Microwave Ablation of Renal Cell Carcinoma: A Comparative Study of Effectiveness and Safety

Winner of the 2022 Young Investigator Award

Purpose: To evaluate differences in efficacy and safety between percutaneous cryoablation (CRA) and microwave ablation (MWA) of renal cell carcinoma (RCC).

Materials and Methods: From 2013 to 2017, consecutive patients with RCC treated with CRA and MWA were retrospectively included. Baseline characteristics (age, gender, race, body mass index [BMI], tumor size, RENAL nephrometry score) were evaluated. Peri- and postprocedural variables (number of probes used, total computed tomography [CT] dose, procedural time, incidence of hematoma and creatinine adverse event [AE] grade ≥1, critical structure involvement, postoperative hospitalization, Clavien-Dindo class ≥1, complete response) were also evaluated. Overall survival (OS) from initial treatment was calculated using Kaplan-Meier estimation and compared using log-rank analysis. Differences in variables were assessed with chi-square and Student’s t-test using JMP statistical software.

Results: A total of 176 patients were evaluated (130 CRA; 46 MWA). The overall mean age was 68 years, and 56% of patients were male. No significant differences in baseline characteristics (age, gender, race, BMI, tumor size, RENAL nephrometry score) were noted. Compared with MWA, CRA was associated with more probes (2.1 ± 1.2 vs 1.4 ± 0.2 probes; P < 0.0001) and longer procedural times (94 ± 3.4 vs 79 ± 6.3 min; P = 0.03) but did not exhibit a significant difference in other peri- or postprocedural variables (total CT dose (2.9 ± 0.2 vs 2.6 ± 0.3 Gy*cm; P = 0.4), hematoma incidence (30% vs 22%; P = 0.4), grade 1 or greater creatinine AE (5% vs 12%; P = 0.3), critical structure involvement (30% vs 22%; P = 0.4), postoperative hospitalization (24% vs 14%; P = 0.2), Clavien-Dindo class 1 or greater (25% vs 14%; P = 0.2), complete response (93% vs 90%; P = 0.4), and OS (4.1 vs 4.7 years; P = 0.8).

Conclusions: For patients with RCC, CRA and MWA offer similar effectiveness and safety profiles even though CRA is associated with more ablation probes and procedural time.