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Glossary

Click on a letter to go to that section of the alphabet:

A

Adjuvant therapy
A treatment method used in addition to the primary therapy. Radiation therapy often is 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.

Apoptosis (AY-pup-TOE-siss)
A type of cell death in which a series of molecular steps in a cell leads to its death. This is the body’s normal way of getting rid of unneeded or abnormal cells. The process of apoptosis may be blocked in cancer cells. Also called "programmed cell death."

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B

Benign tumor
A growth that is not a cancer and does not spread to other parts of the body.

Biological therapy
Treatment by stimulation of the body's immune defense system.

Biopsy
The removal of a sample of tissue to see whether cancer cells are present.

Brachytherapy (BRAK-ee-THER-ah-pee)
Internal radiation treatment achieved by implanting radioactive material directly into the tumor or very close to it. Sometimes called "internal radiation therapy."

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C

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
Treatment with anticancer drugs.

Cobalt 60
A radioactive substance used as a radiation source to treat cancer.

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D

Dietician (also "registered dietician")
A professional who plans diet programs for proper nutrition.

Dosimetrist (do-SIM-uh-trist)
A person who plans and calculates the proper radiation dose for treatment using a treatment planning computer system.

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E

Electron beam
A stream of particles that produces high-energy radiation to treat cancer.

External radiation
Radiation therapy that uses a machine located outside of the body to aim high-energy rays at cancer cells.

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F

Fluoride
A chemical applied to the teeth to prevent tooth decay.

Fractionation
Dividing the total dose of radiation into smaller doses in order to give healthy tissue time to repair itself.

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G

Gamma rays
High-energy rays that come from a radioactive source such as cobalt-60.

Gray
A measurement of absorbed radiation dose; 1 Gray = 100 rads.

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H

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 radiation therapy."

Hyperfractionated radiation
Division of the total dose of radiation into smaller doses that are given more than once a day.

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I

IMRT
Intensity Modulated Radiation Therapy. The intensity of the radiation can be changed during treatment to spare more adjoining normal tissue than with radiation therapy and allows for increasing the dose of radiation to the tumor. IMRT is also known as "conformal radiation."

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.

Interstitial radiation
A radioactive source (implant) placed directly into the tissue (not in a body cavity).

Intracavitary radiation
A radioactive source (implant) placed in a body cavity such as the chest cavity or the vagina.

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.

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J

K

L

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 "LINAC."

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M

Malignant
Cancerous (see "cancer").

Medical oncologist
A doctor who specializes in using chemotherapy to treat 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.

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N

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O

Oncologist
A doctor who specializes in treating cancer.

Oncology
The branch of medicine devoted to the diagnosis and treatment of cancer.

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P

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 trained in the use of treatments such as exercise and massage.

Platelets
Special blood cells that help stop bleeding.

Port (also "treatment field")
The area of the body through which external beam radiation is directed in order to reach a tumor.

Prosthesis
An artificial replacement of a part of the body.

Protraction
The period of time during which a course of radiation is given.

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Q

R

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 doctor who specializes in using radiation to treat cancer.

Radiation oncology nurse
A registered nurse or licensed practical nurse who has extensive training in oncology and radiation therapy.

Radiation physicist
A person trained to ensure that the radiation machine delivers the right amount of radiation to the treatment site.

Radiation therapist
A person with special training who runs 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, 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.")

Radioisotope
A radioactive form of an element.

Radiologist
A physician with special training in reading 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.

Radiotherapy
See "radiation therapy."

Remote brachytherapy
See "high-dose-rate remote brachytherapy."

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S

Sealed radiation source
A metal seed or capsule containing a radioisotope, used for brachytherapy procedures.

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.

Social worker
A mental health professional with a master's degree in social work (MSW). A social worker can provide assistance in dealing with medical, psychological, social and educational needs.

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T

Teletherapy
Treatment in which the radiation source is at a distance from the body. Linear accelerators and cobalt machines are used in teletherapy.

Treatment port or field
The place on the body at which the radiation beam is aimed.

Tumor
An abnormal mass of tissue. Tumors are either benign or malignant.

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U

Unsealed internal radiation therapy
Internal radiation therapy given by injecting a radioactive substance into the bloodstream or a body cavity. This substance is not sealed in a container.

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V

W

White blood cells
The blood cells that fight infection.

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X

X-ray
High-energy radiation that can be used at low levels to diagnose disease or at high levels to treat cancer.

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Y

Z

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