Ablation of a Site of Progression With Stereotactic Body Radiation Therapy Extends Sunitinib Treatment From 14 to 22 Months

Historically, chemotherapy for clear-cell renal cell carcinoma (ccRCC) has not been effective, and fewer than 25% of patients respond to cytokine therapy. Recommended treatment for patients with advanced ccRCC includes molecularly targeted agents such as sunitinib, a kinase inhibitor that targets vascular endothelial growth factor and platelet-derived growth factor receptors. A randomized phase III study established the benefits of sunitinib over interferon alfa, demonstrating an improvement in median progression-free survival (PFS) from 5 to 11 months and a 31% response rate. When a patient progresses on a systemic agent, the typical course of action is to switch therapies. We present a patient with broadly metastatic ccRCC who experienced progression at a single site while receiving sunitinib. After 14 months of sunitinib treatment, stereotactic body radiation therapy (SBRT) to the progressing metastasis allowed the patient to continue on sunitinib for 8 additional months until progression.