Oncology Glossary

Adjuvant therapy: A treatment method used in addition to the primary therapy. Radiation therapy often is used as an adjuvant to surgery.
Alopecia: Hair loss.
Anesthesia: Loss of feeling or sensation resulting from the use of certain drugs or gases.
Antiemetic: A medicine to prevent or treat nausea or vomiting.
Benign Tumor: A term used to describe a tumor that is not cancerous.
Biologic Therapy: Treatment that stimulates the body's immune defense system to fight infection and disease. Also called immunotherapy or immune therapy.
Biopsy: The removal of a sample of tissue that is examined under a microscope to see if cancer cells are present.
Brachytherapy: Internal radiation treatment achieved by implanting radioactive material directly into the tumor or close to it. Sometimes called internal radiation therapy.
Cancer: A general term for more than 100 diseases that have uncontrolled, abnormal growth of cells that can invade and destroy healthy tissues.
Catheter: A thin, flexible tube through which fluids enter or leave the body.
Chemotherapy: The use of drugs to treat cancer.
Dosimetrist: A person who plans and calculates the proper radiation dose for treatment.
Electron Beam: A stream of high-energy particles called electrons used to treat cancer.
External Radiation: Radiation therapy that uses a machine located outside of the body to aim high-energy rays at cancer cells.
Fractionation: Dividing the total dose of radiation into smaller doses in order to give healthy tissue time to repair itself.
Gray: A measurement of the amount of radiation dose absorbed by the body (1 Gray = 100 rads).
High-dose-rate Remote Brachytherapy: A type of internal radiation in which each treatment is given in a few minutes while the radioactive source is in place. The source of radioactivity is removed between treatments. Also known as high-dose-rate remote afterloading radiation therapy.
Hyperfractionated Radiation: Division of the total dose of radiation into smaller doses that are given more than once a day.
Immune Therapy: Treatment that stimulates the body's immune defense system to fight infection and disease. Also called biologic therapy or immunotherapy.
Implant: A small container of radioactive material placed in or near a cancer.
Internal Radiation: A type of therapy in which a radioactive substance is implanted into or close to the area needing treatment. Also called brachytherapy.
Interstitial Radiation: A type of internal radiation in which a radioactive source (implant) is placed directly into the tissue (not in a body cavity).
Intracavitary Radiation: A type of internal radiation in which a radioactive source (implant) is placed in a body cavity, such as the vagina.
Intraoperative Radiation: A type of external radiation therapy used to deliver a large dose of radiation to the tumor 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 mega-voltage (MeV) linear accelerator or a linac.
Malignant: Cancerous.
Medical Oncologist: A doctor who is specially trained in the diagnosis and treatment of cancer and who specializes in the use of chemotherapy and other drugs to treat cancer.
Metastasis: The spread of cancer cells to distant areas of the body by way of the lymph system or bloodstream.
Oncologist: A physician who specializes in caring for people who have cancer.
Oncology: The branch of medicine devoted to the diagnosis and treatment of cancer.
Palliative Care: Treatment to relieve, rather than cure, symptoms caused by cancer. Palliative care can help people live more comfortably.
Physical Therapist: A health professional who uses exercises and other methods to restore or maintain the body's strength, mobility, and function.
Platelets: Special blood cells that help stop bleeding.
Port (also treatment field): The area of the body through which external beam radiation is directed to reach a tumor.
Prosthesis: An artificial replacement of a part of the body.
Protraction: The time during which a course of radiation is given.
Rad: Short form for "radiation absorbed dose"; a measurement of the amount of radiation absorbed by the body (100 rad = 1 Gray).
Radiation: Energy carried by waves or a stream of particles.
Radiation Oncologist: A doctor who specializes in using radiation to treat cancer. Radiation physicist: A person trained to ensure that the radiation machine delivers the right amount of radiation to the treatment site. Assists the radiation oncologist and dosimetrist in the design, planning, and calculation of the proper dose for radiation treatment.
Radiation Therapist: A person with special training to work the equipment that delivers the radiation.
Radiation Therapy: The use of high-energy penetrating rays or subatomic particles to treat disease. Types of radiation include: x-ray, conformal, electron beam, alpha and beta particle, and gamma ray. Radioactive substances include: cobalt, radium, iridium cesium, iodine, and palladium.
Radiation Therapy Nurse: A nurse who has extensive training in oncology and radiation therapy.
Radiologist: A physician with special training in reading and interpreting diagnostic x-rays and performing specialized x-ray procedures.
Radioresistance: When cells do not respond easily to radiation.
Radiosensitivity: How susceptible a cell, cancerous or healthy, is to radiation. Cells that divide frequently are especially radiosensitive and are more affected by radiation.
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.
Treatment Field (or port): The place on the body at which the radiation beam is aimed.
Tumor: An abnormal lump or mass of tissue. Tumors are either benign (noncancerous) or malignant (cancerous).
White Blood Cells: The blood cells that help defend the body against infection.
X-ray: One form of radiation that can be used at low levels to produce an image of the body on film or at high levels to destroy cancer cells.