Introduction
Renal cancer constitutes 2-3% of adult cancers. It is the seventh most common cancer type in
males and the ninth most common type of cancer in females (1). Today, the incidence of
small renal masses (SRMs) is increasing with the development of imaging modalities and
with the increase in the public awareness (2). In current practice, Nephron-sparing surgery(NSS) is the new gold standard in the treatment of SRMs (2).
Current minimal invasive ablative treatments including radiofrequency ablation (RFA),
microwave ablation (MWA) and high intensity focused ultrasound ablation (HIFU) are
alternative teratments for SRMs, especially for T1a renal tumors (3). These treatments have
some advantages, such as less complication rate, shorter recovery and hospital stay and less
ischemic injury to the kidney than surgical treatments. (4, 5) Another advantage of ablative
therapies is the ability to provide curative and nephron-sparing treatment for patients who are
inappropriate for the surgical treatments (4-7). EAU guideline offer active surveillance,
radiofrequency ablation and cryoablation to elderly and comorbid patients with small renal
masses. However, there is no recommendation for RFA and cryoablation due to the inadequacy of existing data. In the AUA guideline, thermal ablation may be preferred in small renal masses with a T1a stage of 3 cm. (8, 9) In this study, we aimed to evaluate the operative and long-term oncological outcomes of RFA and MWA.