Reports on new radiosurgery technologies, the use of novel imaging techniques for dose planning and results analyses, outcomes for patients with benign and malignant brain tumors, vascular malformation radiosurgery, and radiobiology and physics studies are the main themes in this third volume of the peer-reviewed high-quality book series 'Radiosurgery’. It provides reports from the 1999 meeting of the International Stereotactic Radiosurgery Society (ISRS) in Sydney, Australia. As the medical field of radiosurgery grows scientifically, a record number of scientific submissions for publication were received. A selection of the important topics discussed in the ISRS meeting are presented in this volume. This publication is of special interest to neurologists, neurosurgeons and radiation oncologists who need up-to-date and precise information to keep up with the important developments in the field and their impact on the management of brain disease.