To determine whether microwave ablation (MWA) has equivalent outcomes to cryoablation (CA) in terms of technical success, adverse events, local tumor recurrence and survival in adult patients with solid enhancing renal masses ≤ 4 cm.
A retrospective review of 279 small renal masses (≤ 4cm) in 257 patients (median age: 71 years; range: 40-92) treated with either CA (n=191) or MWA (n=88) between January 2008 and December 2020 at a single, high-volume institution. Evaluations of adverse events, treatment effectiveness, and therapeutic outcomes were conducted for both MWA and CA. Disease-free, metastatic-free, and cancer-specific survival rates were tabulated. The estimated glomerular filtration rate (eGFR) was employed to examine treatment-related alterations in renal function.
No difference in patient age (p=0.99) or sex (p=0.06) was observed between the MWA and CA groups. Cryoablated lesions were larger (p<0.01) and of greater complexity (p=0.03). The technical success rate for MWA was 100%, whilst one of 191 cryoablated lesions required retreatment for residual tumor. There was no impact on renal function following CA (p=0.76) or MWA (p=0.49). Secondary analysis using propensity score matching demonstrated no significant differences in local recurrence rates (p=0.39), adverse event rates (p=0.20), cancer free survival (p=0.76), or overall survival (p=0.19) when comparing matched cohorts of patients who underwent MWA and CA.
High technical success and local disease control were achieved for both MWA and CA. Cancer-specific survival was equivalent. Higher adverse event rates following CA may reflect the tendency to treat larger, more complex lesions with CA.
Journal of vascular and interventional radiology : JVIR. 2024 Feb 13 [Epub ahead of print]
George Sun, John R Eisenbrey, Amanda R Smolock, Costas D Lallas, Kevin F Anton, Robert D Adamo, Colette M Shaw
Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA., Department of Radiology, Thomas Jefferson University Hospital, Philadelphia, PA., Division of Vascular and Interventional Radiology, Department of Radiology, Medical College of Wisconsin, Milwaukee, WI., Department of Urology, Thomas Jefferson University Hospital, Philadelphia, PA.