Stereotactic techniques for radiotherapy tumors of the central nervous system

Abstract

As a result of a constant progress in accurate patient positioning and fixation techniques, as well as new posibilities in imaging methods, stereotactic radiosurgery (SRS) has been proved to be a new useful method of intracranial leasions' treatment. Stereotactic technique is a method using reference markers to precisely locate a target within three dimensional boundaries. Stereotactic radiosurgery is used most frequently in the treatment of arteriovenous malformations (AVM), solitary brain metastases, and acoustic nerve neuromas. In AVM, local control is obtained in 60-90% with late toxicity risk in range of 6-10% after delivering a single, high dose of ionizing radiation. Percentage response depends on AVM's size (volume). It is possible to obtain local control in more then 95% patients with acoustic nerve neuroma, with acceptable late toxicity risk. The treatment's effects of solitary brain metastases are comparable to surgical treatment. Other clinical indications for SRS are meningiomas, high grade gliomas, and pituitary adenomas.