Radiation therapy in the management of patients with limited brain metastases

Brain metastases are the most common form of intracranial tumor in adults and an increasingly important cause of morbidity and mortality. Rising incidence is attributed to advanced radiographic imaging and prolonged survival due to improvements in cancer therapy (including systemic therapies) that are not as effective in treating intracranial disease. Standard treatment options for brain metastases include resection, whole-brain radiation therapy (WBRT), stereotactic radiosurgery, or a combination of these modalities. Most patients with brain metastases receive some form of radiation therapy during the course of their illness, and for the majority of them, the prognosis is poor and WBRT remains the standard. However, within this very diverse patient population, subgroups exist in which prolonged survival is possible. In recent years, several randomized controlled trials have clearly demonstrated the efficacy of stereotactic radiosurgery in well-selected patients. This, along with an increased recognition of the late neurocognitive effects of WBRT, has led many to question the role of upfront WBRT in patients with limited intracranial metastases. In this review, we summarize the evolving role of radiotherapy in the management of brain metastases and then discuss the issues related to neurotoxicity from radiation and future areas of investigation.