Percutaneous microwave ablation for local control of metastatic renal cell carcinoma

The purpose of the article is to evaluate the safety and oncologic efficacy of microwave ablation for metastatic renal cell carcinoma (mRCC). From September 2011 to December 2016, 33 mRCC were ablated in 18 patients using percutaneous microwave ablation. Sites of mRCC include retroperitoneum (n = 12), contralateral kidney (n = 6), liver (n = 6), lung (n = 5), adrenal gland (n = 5). Technical success, local, and distant tumor progression, and complications were assessed at immediate and follow-up imaging. The Kaplan-Meier method was used for survival analysis. Technical success was achieved for 33/33 (100%) mRCC tumors. Ablation provided durable local control for 28/30 (93%) mRCC tumors in 17 patients at a median duration of clinical and imaging follow-up of 1.6 years (IQR 0.7-3.6) and 0.8 years (IQR 0.5-2.7), respectively. In-hospital and perioperative mortality was 0%. There were 5 (15%) procedure-related complications including one high-grade event (Clavien-Dindo III). Four patients have died from mRCC at a median of 1.3 years (range 0.7-5.1) following ablation. Estimated OS (95% CI number still at risk) at 1, 2, and 5 years were 86% (53-96%, 11), 75% (39-92%, 8), and 75% (39-92%, 3), respectively. Microwave ablation of oligometastatic renal cell carcinoma is safe and provides durable local control in appropriately selected patients.