Intracranial Stereotactic Radiosurgery in High Risk Patients with Metastases from Radioresistant Primary Tumors

Abstract

Traditionally radioresistant brain metastases including melanoma, renal cell carcinoma, and sarcoma have poor outcomes with supportive care and whole brain radiotherapy (WBRT) alone. Although recent advances in biologic and targeted agents have improved systemic disease control in some patients with melanoma and renal cell carcinoma, such agents have poor penetration and are relatively ineffective in controlling brain metastases. Nevertheless, the ability to provide biologically ablative doses of radiotherapy by radiosurgery still can yield excellent local control similar that found in classically non-radioresistant brain tumors. Although conventional radiobiological models suggest that these patients will not respond to conventionally fractionated radiation therapy treatment, stereotactic radiosurgery allows high doses of radiation to be delivered to the target, while minimizing dose to normal tissue. Here we present treatment strategies and clinical outcome data in the management of such patients. Given the excellent local control following radiosurgery in this group of patients we propose that radiosurgery provides a clinical benefit to this group of patients. The use of whole brain radiation therapy should be considered to improve local control, although can be omitted in selected groups of patients.