Karmanos - Crittenton Cancer Center Definitions to several words frequently used in radiation therapy Adjuvant therapy A treatment method used in addition to the primary therapy. Radiation therapy is often used as an adjuvant to surgery. Alopecia (al-oh-PEE-she-ah) Hair loss Anesthesia Loss of feeling or sensation resulting from the use of certain drugs or gases. Antiemetic (an-tee-eh-MET-ik) A medicine to prevent or relieve nausea or vomiting. Benign tumor A growth that is not a cancer and does not spread to other parts of the body. Biopsy The removal of a sample of tissue to see whether cancer cells are present. Brachytherapy (BRAK-ee-THER-ah-pee) Treatment with radioactive sources placed into or very near the tumor or affected area. This includes surface application, body cavity application (intracavitary), and placement into the tissue (interstitial). Sometimes this term is used interchangeably with "internal radiation therapy." CT (CAT) Scan An x-ray procedure enhanced by a computer which creates a three-dimensional view, clearly showing both bone and soft tissue. Cancer A general term for several diseases that have uncontrolled, abnormal growth of cells that can invade and destroy healthy tissues. Chemotherapy Treatment with anticancer drugs. Cobalt 60 A radioactive substance used as a radiation source to treat cancer. Conformal therapy the process of geometrically shaping the radiation beam so that its radiation dose contour corresponds to the target. Also known as Intensity Modulated Radiation therapy (IMRT). Dietician An individual who plans diet programs for proper nutrition. Dosimetrist (do-SIM-uh-trist) An individual who plans and calculates the proper radiation dose for treatment. Endocavitary implant A radioactive source placed in a body cavity such as the chest cavity or the vagina. External radiation Radiation therapy that uses a machine located outside of the body to aim high-energy rays at cancer cells. Gamma rays Same as x-rays but from a different radioactive source. Gray A measurement of absorbed radiation dose; 1gray = 100 rads. Hyperfractionated radiation Division of the total dose of radiation into smaller doses that are given more than once a day. Implant A small container of radioactive material placed in or near a cancer. IMRT Intensity Modulated Radiation Therapy. (See also conformal therapy and peacock therapy.) Internal radiation A type of therapy in which a radioactive substance is implanted into or close to the area needing treatment. (See also interstitial implant and intracavitary implant.) Interstitial implant A radioactive source placed directly into the tissue (not in a body cavity). Intraoperative radiation A type of external radiation used to deliver a large dose of radiation therapy to the tumor bed and surrounding tissue at the time of surgery. Linear accelerator A machine that creates high-energy radiation to treat cancers using electricity to form a stream of fast-moving subatomic particles. Also called megavoltage (MeV) linear accelerator or a linac. Malignant Cancerous (see cancer). Metastasis The spread of a cancer from one part of the body to another. Cells in the second tumor are like those in the original tumor. Oncologist A doctor who specializes in the treatment of cancer. Palliative therapy A treatment that may relieve symptoms without curing the disease. Peacock therapy A specific radiation therapy product designed to deliver intensity modulated radiation therapy for the treatment of cancer. Rad Short form for "radiation absorbed dose;" a measurement of the amount of radiation absorbed by tissues (100 rad = 1 gray). Radiation Energy carried by waves or a stream of particles. Radiation oncologist A physician who specializes in using radiation to treat disease. Radiation physicist An individual trained to ensure that the radiation machine delivers the right amount of radiation to the treatment site. Radiation therapist An individual with special training who operates the equipment that delivers radiation. Sometimes called a "radiation technologist." Radiation therapy The use of high-energy penetrating rays or subatomic particles to treat disease. Types of radiation include x-ray, electron beam, alpha and beta particles, and gamma rays. Radioactive substances include cobalt, radium, iridium, and cesium. (See also gamma rays, brachytherapy, teletherapy, and x-ray.) Also called Radiotherapy. Radiologist A physician with special training in reading diagnostic x-rays and performing specialized x-ray procedures. Remote Afterloading Brachytherapy A type of radiation treatment where the radioactive source is inserted into delivery tubes from a computerized control unit in a separate, or remote, location after the tubes have been precisely placed for treatment by a radiation oncologist. Simulation A process involving special x-ray pictures that are used to plan radiation treatment so that the area to be treated is precisely located and marked for treatment. Stereotactic Radiosurgery A non-invasive treatment technique of focusing multiple small beams of radiation at a targeted small intracranial lesion. Treatment port The place on the body at which the radiation beam is aimed. Tumor An abnormal mass of tissue. Tumors are either benign or malignant. X-ray High-energy radiation that can be used at low levels to diagnose disease or at high levels to treat cancer.