The exponential growth and acceptance rate of stereotactic radiosurgery (as measured by recognized indications and number of treating centers) has been coupled with concern about its possible over-utilization and long-term risks. To provide the most balanced account possible of this controversy, each chapter in this book is followed by a critical commentary from an expert on each indication, often one who does not perform radiosurgery. As a result, the reader benefits from an intelligent discussion of the clinical indications by both advocates and critics of radiosurgery. The book’s contributors, true leaders in the field from the United States, Europe, and Japan, represent a wide variety of experience and opinion. Whereas earlier texts devoted large sections to the actual equipment used to perform radiosurgery, as the field matures it is now clear that the technique can be performed equally well with a variety of technologies. Thus, this book has just one chapter on technology, and otherwise concentrates on appropriate indications, use, and patient outcomes. It is the author’s hope that neurosurgeons, radiation oncologists and neurologists will use the information in this text to decide for themselves the role that radiosurgery should play in treating patients with neurologic disorders.