Spine Radiosurgery in the Management of Renal Cell Carcinoma Metastases.

Renal cell carcinoma (RCC) presents an interesting challenge in radiation oncology. Improved systemic therapy has significantly prolonged survival. Modern imaging has allowed practitioners to effectively identify patients with oligometastatic disease. Conventionally fractionated radiation therapy is a first-line treatment option for palliation of bone metastases, including the spine, but has limited efficacy and durability. Conventional treatment may not be sufficient in metastatic RCC because of the disease's relative radioresistance. Improved technology, including custom immobilization and on-board treatment imaging, has allowed ultra-high-dose radiation therapy, or stereotactic radiosurgery (SRS), to effectively treat metastatic disease in the spine. Safety and efficacy have already been established for intracranial disease and data are emerging for extracranial metastasis. Spine SRS offers local control rates and durable pain improvement in up to 90% of patients. Many series have already reported its effectiveness, and prospective multi-institutional trials are underway. Spine SRS should be strongly considered in select patients with refractory or oligometastatic disease.