This volume will cover what is known regarding the biology and treatment of CNS metastasis, including novel chapters such as the future of targeted therapies. It will begin with an overview of the natural history and risk factors for CNS metastases that will broadly cover all cancer histologies.   This will be followed by 3 chapters that will cover the biology. These include: molecular biology, discussing what is known about specific genes/proteins involved in the process and model systems to study brain metastasis; the brain microenvironment, focusing on how it is different from the microenvironment of other organs of the body; and the blood-brain barrier, which includes a discussion of permeability with respect to brain metastases. A chapter on experimental imaging will cover both the biology of brain metastasis from an imaging perspective and use of imaging techniques to study brain metastases. The clinical chapters will discuss treatment options with separate chapters on surgery, chemotherapy and radiation. In addition, leptomeningeal metastasis will be given its own chapter. Finally, quality of life issues will be the concluding chapter.