Stereotactic radiosurgery for brain lesions: an observation and follow-up.

Stereotactic radiosurgery (SRS) is a technique for obliterating intracranial targets that are inaccessible or unsuitable for open surgical techniques. By means of well-collimated beams of ionizing radiation, a high-dose, single fraction of radiation is delivered to a defined volume of tissue. The entrance and exit doses are distributed in such a way that tissue outside the target is minimally affected.