Brain Tumor Glossary of Terms

Easily explore the meaning of hundreds of medical terms or words, many directly used in brain tumor-related terminology.


A device which radiates small areas of the brain. The x-knife can focus radiation therapy to a specific small area. Use of this type of radiation therapy allows a patient to receive radiation in smaller doses on repeated occasions and to be treated for tumors that are very close to very critical structures such as the visual nerves, which are sensitive to radiation. The x-knife is often used to remove pieces of the tumor left behind during surgery.

X-ray therapy

A type of radiation therapy that uses high-energy radiation from x-rays to kill cancer cells and shrink tumors.


A type of high-energy radiation. In low doses, x-rays are used to diagnose diseases by making pictures of the inside of the body. In high doses, x-rays are used to treat cancer.

Xanthoastrocytoma, Pleomorphic

A low-grade astrocytic tumor which may exhibit anaplastic features and generally carries a relatively favorable prognosis and should not be classified with other high-grade gliomas, such as anaplastic astrocytoma and glioblastoma multiforme.