During the last few years stereotactic radiosurgery has become a partner of equal rank within the discipline of neurosurgery. Today it is regarded as being of the same importance as microsurgery and endovascular neurosurgery, branches which have also progressed rapidly in recent years. Breakthrough success, however, requires a combined effort of all partners involved.The editors have brought together leading experts in the fields of neurosurgery, neuroradiology, neurology, neuropathology, neuroanatomy, radiation oncology, and biophysics to discuss indications and therapeutic strategies in the treatment of arteriovenous malformations and intracranial tumors and to find a common basis for their future work.