Stereotactic body radiation therapy (SBRT) for metastatic renal cell carcinoma: A multi-institutional experience
Raj Singh, Hayden Ansinelli, Dana Sharma, Jan Jenkins, Joanne Davis, Sanjeev Sharma and John Austin Vargo
Objectives: Examine local control(LC), overall survival(OS), and toxicity following stereotactic body radiation therapy(SBRT) for patients with metastatic renal cell carcinoma(mRCC).
Methods: A multi-institutional registry was queried. Potential predictive factors of LC and OS were evaluated with a Cox-proportional hazards model for multivariate analysis(MVA).
Results: We identified 115 mRCC patients with 181 lesions. Median biologically effective dose (BED7) was 72.9 Gy7 (range: 42.9–231.4 Gy7) with a median dose/fraction of 10 Gy (range: 5-24 Gy). Utilizing both Karnofsky Performance Score (KPS) and presence of osseous metastatic disease as prognostic indicators, estimated 2-year OS rates were 67.7% (95% CI: 49.9-89.5%), 31.8% (95% CI: 19.0-45.3%), and 20% (95% CI: 1.4-54.7%; p=0.0012). One- and 2-year LC rates were 88.2% and 82.7%, respectively, with no prognostic factors identified. Roughly 13% of patients reported toxicities with one Grade 3-5 toxicity.
Conclusion: SBRT was well-tolerated with promising LC. Both KPS and osseous metastatic disease should be considered in determining which patients with mRCC may preferentially benefit from SBRT.
Keywords: Stereotactic body radiation therapy; metastatic renal cell carcinoma; local control; overall survival; bone metastases