The Role of Stereotactic Ablative Body Radiotherapy in Renal Cell Carcinoma

Context: Stereotactic ablative body radiotherapy (SABR) is an emerging treatment modality for primary and metastatic renal cell carcinoma (RCC). Objective: To review and summarise the evidence on the use of SABR in RCC in a narrative review. Evidence acquisition: We performed an online search of the PubMed database from January 2000 through December 2021. Studies of SABR/stereotactic radiosurgery (SRS) targeting primary, extracranial, or intracranial metastatic RCC were included. Evidence synthesis: Two meta-analyses (including 54 studies), and 13 prospective and 20 retrospective studies were included in this review. In aggregate, SABR for 589 primary RCCs in 575 patients resulted in a local control rate of above 90% with grade 3–4 toxicity of 0–9%. Similarly, the local control rate ranged between 90% and 97% with SRS in 1225 patients with intracranial metastatic RCC. SABR was able to delay systemic therapy for at least 1 yr in 70–90% of oligometastatic RCC patients with grade 3–4 toxicity of <10%. As per the early data, the combination of SABR with systemic therapy for metastatic RCC, such as targeted therapy or immunotherapy, appears safe, feasible, and tolerable. Conclusions: We outlined data supporting SABR in the key clinical scenarios of primary and metastatic, including oligometastatic, RCC in lieu of systemic therapy, in combination with systemic therapy, and palliation of brain and spinal metastases. Patient summary: Stereotactic ablative body radiotherapy (SABR) is a relatively new treatment option in kidney cancer. Here, we review the published literature on the experience of using SABR in kidney cancer. The accumulated evidence demonstrates that SABR can be used safely and effectively to treat selected cases of primary or secondary kidney cancer.