The "Talairach" stereotactic multibeam irradiation system developed by the authors allows to irradiate selectively small intracranial or intraorbital lesions localized in the Talairach stereotactic system. The centre of the target volume is placed in the isocentre of rotation of a linear accelerator (160 degrees), a special head fixation allows for a stepwise rotation of the head (145 degrees) around the centre of the lesion. Special collimators adapt the width of the high energy photon beam to the dimensions of the target (some millimeters to 3 cm), creating a high dose radiation field limited to the lesion (deep AVM, pituitary adenomas, small gliomas in critical areas etc.).