**Part 1**

**Neoplastic Disorders** 

**1** 

*USA* 

**Outcomes Following** 

*1Yale University School of Medicine* 

*2Hofstra North Shore-LIJ School of Medicine* 

Veronica L.S. Chiang1

**Gamma Knife for Metastases** 

Henry S. Park1, James B. Yu1, Jonathan P.S. Knisely2 and

Brain metastases occur in approximately 20-40% of all cancer patients, with an annual incidence of 170,000-200,000 cases, outnumbering primary brain tumors by a factor of ten to one (Gavrilovic, 2005; Posner, 1992). The management of brain metastases has evolved significantly in the past 10-20 years. These changes are attributable not only to improvements in the fields of neurosurgery and radiation oncology but also to refinements in diagnostic imaging and systemic therapy. Management of brain metastases requires a multidisciplinary approach. In this chapter, we will explore the evolving role of radiosurgery in the treatment of brain metastases and the controversies that have surrounded this promising therapeutic modality, especially in the context of evolving

While up to 20% of patients can present with brain metastases as their first sign of cancer, most typically occur later in the course of disease. The finding of a brain metastasis in a cancer patient has historically indicated a continued progression of systemic disease, portending a poor prognosis and shifting the primary goal of treatment to relief of symptomatology. Treatment of brain metastases was therefore, by definition, palliative. Prior to the availability of computerized axial tomographic scanning (CT scan) and magnetic resonance imaging (MRI), brain metastases were diagnosed when they caused symptomatology, including seizures, the effects of increased intracranial pressure, or focal neurological deficits from mass effect on critical structures. Without treatment, the survival rate after diagnosis averaged approximately 4-6 weeks (Al-Shamy & Sawaya, 2009) despite

This dismal view of brain metastases outcomes began to change with the introduction of whole brain radiation therapy (WBRT). One of the first reports of radiation therapy for brain metastases was by Lenz & Fried (1931) for the palliation of breast cancer patients with intracranial metastases. The initial reasoning behind WBRT was to treat clinically symptomatic metastatic disease, and the ability to control presumed, clinically silent, and

**1. Introduction** 

systemic management protocols.

**2. Whole brain radiation therapy** 

the use of glucocorticoids and ongoing systemic therapy.
