(UroToday.com) The 2022 EAU Section of Oncological Urology (ESOU) Annual Meeting included a session on locally advanced and metastatic renal cancer and a presentation by Dr. Shankar Siva discussing the role of stereotactic ablative body radiotherapy (SABR) for kidney cancer. Dr. Siva notes that renal cell carcinoma (RCC) has historically been considered a radioresistant disease. Looking at data from the mid-1980s, among 125 patients with metastatic RCC treated for palliation, doses ranging from 20 Gy – 60 Gy achieved a 65% response rate. However, over the last several years, the dogma of RCC being radioresistant has been challenged with improving technology and therapeutics. Preclinical studies from the mid-1990s suggested that a small fraction of cells are killed at doses of 2 Gy, whereas there is logarithmic cell death at doses of > 6 Gy. Dr. Siva notes that a different mechanism of cell kill is likely observed with high-dose radiation (ie. SABR), including endothelial apoptosis, leading to ceramide/sphingomyelinase induced cell death, and pro-inflammatory signaling for adaptive immunity:1