Stereotactic body irradiation for metastasis from renal carcinoma: A retrospective study.

Background: Renal cell carcinoma (RCC) has traditionally been considered to be radioresistant. Response rates are believed to be improved by a high dose of stereotactic body radiotherapy (SBRT). A retrospective analysis was conducted of patients treated with SBRT for metastatic disease from RCC. Material and methods: We reviewed records from 20 patients who underwent SBRT for a total of 30 RCC metastases from 2015 to 2020. Patients were included who had a confirmed primary RCC and radiographic evidence of metastasis, either synchronous or metachronous. The most common SBRT fractionation was 30 Gy in 3 fractions. Results: Median age was 60 years (range, 40-77 years) and 60% were male. After a median follow-up of 18 months (range, 3-36 months), overall survival was estimated to be 85% and 70%, at 1 and 2 years, respectively, and local control at 2 years was 83.33%. Only 5 patients had documented progression of disease, all of whom received biologically effective dose inferior to 100 Gy, and no patients treated with a higher biologically effective dose had disease, which progressed. The most common acute toxicity was grade 1 fatigue (20%). No grade 3 or higher acute toxicity occurred. Conclusions: Treatment with SBRT in patients with RCC metastases yielded a high local control rate, promising survival rate, and low toxicity.