Multiple Brain Metastases

In the United States every year, estimates of cancer patients diagnosed with brain metastases range from just under 100,000 to nearly 200,000; they affect 20–40% of all patients with cancer within their lifetimes. Patients with a limited number of metastases are candidates for surgery or stereotactic radiosurgery (SRS), with surgery preferred for larger, acutely symptomatic tumors. Patients with more numerous metastases can be treated focally with SRS or with a regional treatment such as whole brain radiation therapy (WBRT), with the latter approach or supportive care preferred for patients with worse prognoses or a significant burden of intracranial disease. Prognostication systems developed to help guide management decisions in patients with brain metastases have identified important factors such as patient performance status, age, tumor histology, intracranial disease volume, and extracranial tumor control. In addition to local necrosis from SRS, neurocognitive decline is a more recently recognized adverse effect that may occur after SRS alone or after whole brain radiation has been employed. Several approaches have recently emerged to reduce these neurocognitive consequences in patients requiring irradiation of brain metastases, including spatial partitioning of SRS, dose sparing of the hippocampi, and pharmacologically decreasing radiation-induced neuronal excitotoxicity. Optimal brain metastasis management and the integration of focal treatments with a changing landscape of systemic management approaches present challenges for oncologists. Better knowledge and better tools facilitate better choices.