Nephron-Sparing Robotic Radiosurgical Therapy for Primary Renal Cell Carcinoma: Single-Institution Experience and Review of the Literature

PURPOSE: We report our single-institution stereotactic body radiation therapy (SBRT) experience on stage I renal cancer with prospectively collected toxicity and efficacy data. METHODS AND MATERIALS: A total of 21 patients with solitary renal tumors, including 14 surgical candidates who refused surgery (66%), were treated with SBRT. Histologic confirmation was obtained on all patients before treatment; 2 had transitional cell carcinoma and 19 had renal cell carcinoma. The median age was 71 years (range, 58-88). Nearly all patients received 48 Gy in 3 fractions. RESULTS: The median follow-up was 78 months (range, 5-107). At 5 years post treatment, the local tumor control rate was 100%. Tumor size decreased by a median value of 5.3% at 1 year post treatment, 15.6% at 2 years post treatment, and 15.4% at 5 years post treatment. Glomerular filtration rate had decreased by a median value of 1.5% at 1 year post treatment, 7.0% at 2 years post treatment, and 14.2% at 5 years post treatment. Three patients experienced grade 1 toxicity; no other treatment-related adverse effects were reported. CONCLUSIONS: SBRT is a promising noninvasive treatment in the management of primary renal cell carcinoma, with evolving clinical evidence demonstrating encouraging results with respect to local control and toxicity.