Radiation Oncology

Radiation Oncology: Glossary of Terms

You may hear many words associated with radiation oncology that you have not heard before. Please ask for an explanation for any terms you may not understand. Your nurse will have a packet of information to give you. You may hear the following common terms before, during and after your treatment.

Adjuvant therapy: Treatment added to the primary treatment to enhance the effectiveness of the primary treatment. Radiation therapy often is used as an adjuvant to surgery.

Alopecia (al-oh-PEE-she-ah): Hair loss.

Anesthesia: Loss of feeling or sensation to prevent pain. Certain drugs or gases called 'anesthetics' are used to achieve anesthesia so that medical procedures may be performed without pain. A local anesthetic causes loss of feeling in part of the body. A general anesthetic puts the patient to sleep.

Antiemetic (an-tee-eh-MET-ik): A medicine that prevents or relieves nausea and vomiting.

Biological therapy: Treatment to stimulate or restore the ability of the immune system to fight infection and disease; also called immunotherapy.

Brachytherapy (BRAK-ee-THER-ah-pee): Internal radiation therapy using an implant of radioactive material placed directly into or near the tumor; also called "internal radiation therapy."

Cancer: A term for diseases in which abnormal cells divide without control. Cancer cells can invade nearby tissues and can spread through the bloodstream and lymphatic system to other parts of the body.

Catheter: A thin flexible, hollow tube through which fluids enter or leave the body. Radioactive materials may be placed in catheters that are placed near the cancer.

Chemotherapy: Treatment with anticancer drugs.

CT (computerized tomography) scan: An x-ray procedure that uses a computer to produce a series of detailed pictures of a cross-section of the body; also called a CAT scan.

Dietitian (also "registered dietitian"): 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.

Electron beam: A stream of electrons (small, negatively charged particles found in atoms) that can be used for radiation therapy.

Electronic Medical Record (EMR): An information and image management system that stores all of a patient's medical information into a single, organized medical report that is stored electronically and can be accessed by multiple sources.

External radiation: The use of radiation from a machine located outside of the body to aim high-energy rays at cancer cells.

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

High dose-rate remote brachytherapy: A type of internal radiation treatment in which the radioactive source is removed between treatments; also known as 'high dose-rate remote radiation therapy.'

Hyperfractionated radiation: Radiation treatment that is given in smaller-than-usual doses two or three times a day.

Implant: A radioactive source in a small holder that is placed in the body in or near a cancer.

Internal radiation: Radiation therapy that uses the technique of placing a radioactive source in or near a cancer.

Interstitial radiation: A radioactive source (implant) placed directly into the cancerous tissue, such as in the head and neck region or the breast.

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

Intraoperative radiation: External radiation treatment given during surgery to deliver a large dose of radiation to the tumor bed and surrounding tissue; also called IORT.

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 (MV) linear accelerator" or a "linac."

Medical oncologist: A doctor who specializes in treating cancer with chemotherapy.

Oncologist: A doctor who specializes in treating cancer.

Palliative care, palliation: Treatment that relieves symptoms but does not cure disease. Palliative care can help people with cancer live more comfortably.

Physical therapist: A health professional trained in the use of such treatments as exercise and massage.

Radiation nurse: A nurse who specializes in caring for people who are undergoing radiation therapy.

Radiation oncologist: A doctor who specializes in treating cancer with radiation.

Radiation physicist: The person who makes sure that the radiation machine delivers the right amount of radiation to the treatment site. In consultation with the radiation oncologist, the physicist also determines the treatment schedule that will have the best chance of killing the most cancer cells.

Radiation therapist: The person who runs the equipment that delivers the radiation.

Radiation therapy: Treatment with high-energy rays (such as x-rays) to kill cancer cells. The radiation may come from outside of the body (external radiation) or from radioactive materials placed directly in the tumor (internal or implant radiation). Types of radiation include x-rays, electron beams, gamma rays, neutron beams, and proton beams. Radioactive substances include cobalt, iridium, iodine and cesium.

Radioactive: Capable of emitting high-energy rays or particles.

Radiologist: A doctor with special training in creating and interpreting pictures of areas inside the body. The pictures are produced with x-rays, magnetic resonance, sound waves, or other types of energy.

Recurrence: Reappearance of cancer cells at the same site or in another location after a disease-free period.

Remote brachytherapy: See high dose-rate remote brachytherapy.

Simulation: The process used to plan radiation therapy so that the target area is precisely located and marked.

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

Tumor: An abnormal mass of excess tissue that results from excessive cell division. Tumors perform no useful body function and may be either benign (not cancerous) or malignant (cancerous).

White blood cells: Cells that help the body fight infection and disease.

X-rays: High-energy radiation that is used in low doses to diagnose disease and in high doses to treat cancer.