Ablative techniques in renal tumours for inoperable patients: Step forward in SBRT

The localized renal cell carcinoma (RCC) is the eighth most common tumour in Spain. While surgical resection remains the gold standard for treatment, some elderly and frail patients may not be suitable candidates for this procedure. In selected cases, ablative therapies provide less invasive alternatives. Recent research has highlighted the potential of Stereotactic Body Radiotherapy (SBRT) as a non-invasive, well-tolerated, and effective treatment for RCC. This review aims to examine recent advances in SBRT for localized RCC, focusing on patient selection, treatment modalities and delivery, as well as efficacy and tolerance assessment.

A narrative literature review of English articles using Pubmed, Scopus, Cochrane, Google Scholar and Science Direct databases was performed focusing on prospective and relevant retrospective studies. Search terms included "kidney cancer", "renal cell carcinoma", "stereotactic radiotherapy", "radiofrequency ablation", "cryoablation", "microwave ablation", "SBRT" and "SABR".

Studies have reported local control rates ranging from 80% to 100% with SBRT. The decline in glomerular filtration rate following SBRT is approximately -10 to -13 mL/min over the years. Common toxicities are rare and are mostly classified as CTCAE grade I.

Based on available evidence, SBRT appears to be a viable option for patients with localized RCC who are not surgical candidates, given its high local control rate and favorable safety profile. Therefore, some indications for its use in clinical practice have been purposed according to the available evidence and recommending a case by case discussion in a uro-oncology multidisciplinary setting to optimize patient selection and treatment planning.