RADIOTHERAPY
The use of high-energy radiation from x-rays, gamma rays, neutrons and other sources to treat tumors and destroy cancer cells.

RADIOSURGERY
A radiation therapy procedure that delivers a large dose of radiation to a tumor over one to five treatment sessions.

STEREOTACTIC RADIOSURGERY
Radiation treatment of a tumor that is applied in a single session with a high dose of radiation.

FRACTIONATED STEREOTACTIC RADIOTHERAPY
A series of radiation treatments over a period of time.

IMAGE-GUIDED RADIOSURGERY (IGRS)
Radiation treatment that uses real-time x-ray and CT imaging to deliver precisely focused, high-energy radiation to a tumor.