Basic principles: gamma knife technology and physics - past, present and future radiobiologic considerations in gamma knife radio surgery principles of dose prescription and risk minimization for radiosurgery. Vascular radiosurgery: patient outcomes after arteriovenous malformation radiosurgery gamma knife radiosurgery and particulate embolization of dural arteriovenous fistulas, with a special emphasis on the cavernous sinus stereotactic radiosurgery for cavernous malformations. Benign tumour radiosurgery: gamma knife radiosurgery for acoustic neuromas stereotactic radiosurgery of meningiomas gamma knife radiosurgery for pituitary tumours stereotactic radiosurgery for other skull base lesions. Frontiers of radiosurgery: radiosurgery management of brain metastasis from systemic cancer stereotactic radiosurgery for glial neoplasms stereotactic radiosurgery in the treatment of pineal region tumours gamma knife radiosurgery for the treatment of movement disorders gamma radio knife radiosurgery for trigeminal neuralgia.