Glossary of Cancer Terms
X-ray 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.
X-ray therapy The use of high-energy radiation from X-rays to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy) or from materials called radioisotopes. Radioisotopes produce radiation and can be placed in or near the tumor or in the area near cancer cells. This type of radiation treatment is called internal radiation therapy, implant radiation, interstitial radiation, or brachytherapy.
Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that circulates throughout the body. X-ray therapy is also called radiation therapy, radiotherapy and irradiation.
Xeloda A drug used to treat stage III colon cancer in patients who had surgery to remove the cancer. It is also being studied in the treatment of other types of cancer. Xeloda belongs to the family of drugs called antimetabolites. Also called capecitabine.
xenograft The cells of one species transplanted to another species.
xeroderma pigmentosum A genetic condition marked by an extreme sensitivity to ultraviolet radiation, including sunlight. People with xeroderma pigmentosum are not able to repair skin damage from the sun and other sources of ultraviolet radiation, and have a very high risk of skin cancer.
xerogram A picture of the body recorded on paper rather than on film. Also called a xeroradiograph.
xeroradiograph A picture of the body recorded on paper rather than on film. Also called a xerogram.
xeroradiography A type of x-ray in which a picture of the body is recorded on paper rather than on film.
xerostomia Dry mouth. It occurs when the body is not able to make enough saliva.
XK469R A substance that is being studied in the treatment of leukemia. It belongs to the family of drugs called topoisomerase inhibitors.
XR9576 A substance that is being studied in the treatment of cancer. It may help tumor cells respond again to drugs they have become resistant (unable to respond) to. XR9576 belongs to the families of drugs called multidrug resistance inhibitors and P-glycoprotein antagonists. Also called tariquidar.
XRP9881 A substance that is being studied in the treatment of breast cancer. It belongs to the family of drugs called taxane derivatives.
Xyotax A form of the anticancer drug paclitaxel combined with a protein called poliglumex that may have fewer side effects and work better than paclitaxel. It is being studied in the treatment of breast cancer, ovarian cancer, lung cancer, and other types of cancer. It belongs to the family of drugs called mitotic inhibitors. Also called paclitaxel poliglumex, paclitaxel polyglutamate and CT-2103.