Renal cell carcinoma is a tumor that is not sensitive to conventional radiotherapy. Previous clinical studies on postoperative radiotherapy for high-risk renal cell carcinoma have shown no survival benefit of adjuvant radiotherapy, therefore, adjuvant radiotherapy after radical surgery is not recommended.
Radiotherapy is mainly used for palliative treatment of renal cell carcinoma, such as palliative radiotherapy for patients with local recurrence of tumor bed, regional or distant lymph node metastasis, skeletal, brain or lung metastasis, to achieve pain relief and improve survival quality.
In the last decade, radiotherapy techniques have been rapidly developed, and in some retrospective and clinical phase I or II studies, stereotactic body radiation therapy (SBRT, i.e., single high-dose irradiation in one or several fractionated irradiation patterns) techniques have been gradually used to treat renal cell carcinoma. Retrospective analyses have shown that SBRT can achieve better treatment outcomes than conventional radiotherapy. In several retrospective and clinical phase I or II studies, SBRT has achieved good near-term local control rates and has a good treatment safety profile. In the last two years, several studies of SBRT combined with immune checkpoint inhibitors for advanced renal cell carcinoma have shown high efficiency and local control rates, but the number of reported cases is small and long-term follow-up results are lacking. There are no randomized subgroup studies demonstrating the efficacy of SBRT over conventional fractionated radiotherapy or other local therapies. Therefore, SBRT should only be used as an alternative palliative treatment for renal cell carcinoma in medical centers with technical support for precision radiotherapy and physicians and physiotherapists with extensive radiotherapy experience, or in related clinical studies.