SRS and How it Works

Stereotactic radiosurgery, or SRS, is the most precise method of administering a dose of radiation to an area inside the body, in order to eliminate a tumor or other abnormality. It has been used for some time by neurosurgeons to treat vascular abnormalities and tumors in the brain, both benign and malignant. SRS’s ultra-high precision destroys tumors with high doses of radiation, while sparing the surrounding healthy tissue. In this way SRS provides a noninvasive alternative to surgery, allowing treatment of some otherwise inoperable tumors.

Recent advances in imaging, patient positioning, and targeting have all made SRS appropriate for the treatment of some cancers in other parts of the body as well. Diagnostic images taken before treatment—including computed tomography (CT), positron emission tomography (PET), and magnetic resonance imaging (MRI)—help determine where to aim the radiation. The beams are shaped to match the contours of the tumor and are delivered from many different angles around the body, all converging precisely at the planned target location.

Unlike other forms of radiation therapy that might be delivered over a period of weeks, SRS treatments are usually completed in a single day. (Another treatment method, stereotactic radiotherapy, or SRT, involves just a few treatment sessions.) SRS is most often delivered as an outpatient procedure.