Glossary of Terms

Listed below are the definitions of brachytherapy and cancer-related terms in alphabetical order.

Adjuvant therapy – A necessary addition to current treatments. An example is chemotherapy or radiation therapy after surgery to prevent the return of cancer.

Anesthesia – The loss of feeling or sensation as a result of drugs. General anesthesia causes temporary loss of consciousness (“puts you to sleep”). Local or regional anesthesia numbs only a certain area.

Angioplasty – Dilatation of an occluded blood vessel. This can be done by inflating a balloon catheter to restore blood supply.

Benign tumor – An abnormal noncancerous growth that doesn’t spread to other places in the body.

Biopsy – The removal of a sample of tissue to see whether cancer cells are present. There are several kinds of biopsies. In some, a very thin needle is used to draw fluid and cells from a lump. In a core biopsy, a larger needle is used to remove significantly more tissue.

Brachytherapy – Internal radiation treatment given by placing radioactive material directly into a tumor or close to it. Also called interstitial radiation therapy, intracavitary radiation therapy, intravascular radiation therapy, or seed implantation.

Cancer – Cancer develops when cells in the body begin to grow out of control. Normal cells grow, divide, and die. Instead of dying, cancer cells continue to grow and form new abnormal cells. Cancer cells often travel to other body parts where they grow and replace normal tissue. This process, called metastasis, occurs as the cancer cells get into the bloodstream or lymph vessels.

Carcinogen – A substance known to cause cancer.

Carcinoma – A malignant tumor that begins in the lining layer (epithelial cells) of organs. At least 80% of all cancers are carcinomas.

Catheter – A thin, flexible hollow tube. Catheters can be used to allow fluids to enter or leave the body. Catheters can also be used to insert temporary radioactive sources into tumors, as in breast brachytherapy or high dose rate prostate brachytherapy.

Cervix – The lower, narrow end of the uterus that forms a canal between the uterus and vagina.

Chemotherapy – Treatment with drugs to destroy cancer cells. Chemotherapy is often used alone or with surgery or radiation to treat cancer.

CT scan – Computed tomography scan. A series of detailed pictures of areas inside the body taken from different angles; the pictures are created by a computer linked to an x-ray machine. Also called computerized tomography and computerized axial tomography (CAT) scan.

External beam radiation therapy (External radiation) – Radiation therapy that uses a machine outside of the body to deliver high-energy rays directed at the cancer or tumor.

Gleason score – A system of grading prostate cancer cells describing how aggressive the cancer appears. It is used to determine the best treatment and to predict how well a person is likely to respond to treatment. The lower the Gleason score, the closer the cancer cells are to normal cells, the higher the Gleason score, the more abnormal the cancer cells.

High dose rate remote brachytherapy (HDR) – HDR temporary brachytherapy involves placing very tiny plastic catheters into the treatment area, and then giving radiation treatments through these catheters over a temporary period. With HDR temporary brachytherapy, a computer-controlled machine pushes a single highly radioactive source into the catheters one by one.

Internal radiation – A procedure in which radioactive material sealed in needles, seeds, wires, or catheters is placed directly into or near a tumor. Also called brachytherapy, implant radiation, or interstitial radiation therapy.

Interstitial radiation – A procedure in which radioactive material sealed in needles, seeds, wires, or catheters is placed directly into or near a tumor. Also called brachytherapy, internal radiation, or implant radiation.

Intracavitary radiation – A radioactive source (implant) placed in a body cavity such as the cervix or esophagus.

Low dose rate brachytherapy (LDR) – Brachytherapy in which sources are left in place for the duration of treatment. This includes temporary LDR in which patients are hospitalized for several days of temporary brachytherapy. It also includes permanent LDR in which seeds are permanently placed.

Lymph node (lymph gland) – A rounded mass of lymphatic tissue that is surrounded by a capsule of connective tissue. Lymph nodes are spread out along lymphatic vessels and contain many lymphocytes, which filter the lymphatic fluid (lymph). Lymph nodes are part of the body’s immune system.

Malignant – A cancerous growth with a tendency to invade and destroy nearby tissue and spread to other parts of the body.

Medical oncologist – A doctor who specializes in diagnosing and treating cancer using chemotherapy, hormonal therapy, and biological therapy. A medical oncologist often serves as the main caretaker of someone who has cancer and coordinates treatment provided by other specialists.

Metastasis – The spread of cancer from one part of the body to another. Tumors formed from cells that have spread are called “secondary tumors” and contain cells that are like those in the original (primary) tumor.

Oncologist – A doctor who specializes in treating cancer. Some oncologists specialize in a particular type of cancer treatment. For example, a radiation oncologist specializes in treating cancer with radiation.

Palliative care – Treatment given to relieve symptoms of pain caused by advanced cancer. Palliative therapy does not alter the course of a disease but can improve the quality of life.

Permanent interstitial implant – A procedure in which radioactive material sealed in seeds is placed directly into or near a tumor. Also called brachytherapy, internal radiation, or implant radiation. While the radioactivity decays away the actual seeds remain forever.

Prostate – A gland in the male reproductive system just below the bladder. The prostate surrounds part of the urethra, the canal that empties the bladder, and produces a fluid that forms part of semen.

Radiation – Radiant energy given off by x-ray machines, radioactive substances, rays that enter the Earth’s atmosphere, and other sources.

Radiation dosimetrist – A specialist who measures the amount of radiation exposure during treatment procedures.

Radiation oncologist – A doctor who specializes in using radiation to treat a variety of diseases including cancer.

Radiation physicist – A person who makes sure that the radiation machine or implant delivers the right amount of radiation to the correct site in the body. The physicist works with the radiation oncologist to choose the treatment schedule and dose that has the best chance of killing the most cancer cells.

Radiation therapist – A health professional who gives radiation treatment.

Radiation therapy – The use of high-energy radiation from x-rays, gamma rays, neutrons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy, implant radiation, or brachytherapy). Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that circulates throughout the body.

Restenosis – Narrowing of a blood vessel (usually a coronary artery) following the removal or reduction of a previous narrowing (angioplasty).

Seeds – Radioactive pellets, approximately the size of a grain of rice, used in brachytherapy.

Stage – The extent of a cancer within the body, especially whether the disease has spread from the original site to other parts of the body.

Stent – A device placed in a body structure (such as a blood vessel or the gastrointestinal tract) to provide support and keep the structure open.

Temporary interstitial implant – A procedure in which radioactive material sealed in needles, seeds, wires, or catheters is temporarily placed directly into or near a tumor.

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

Tumor staging – This is an important step in the management of cancer. Typically, several tests are performed to determine 3 things. The first part is to quantify the size and extent of a primary cancer. The second is to determine whether nearby lymph nodes are involved by the cancer. The third is to check whether cancer has spread through the blood stream to other parts of the body. Using this information, people with cancer are assigned a stage. This helps to determine the best course of treatment and it also predicts the response to treatment. Each type of cancer has a specific staging system.

Ultrasound – A test that bounces sound waves off tissues and internal organs and changes the echoes into sonograms (pictures).

Unsealed internal radiation therapy – Radiation therapy given by injecting a radioactive substance into the bloodstream or a body cavity, or by swallowing it. This substance is not sealed in a container.

Vascular – Relating to or containing blood vessels.

Volume study – This is a procedure used in prostate brachytherapy to map out the prostate gland. An ultrasound probe is placed in the rectum to get images of the prostate. Once the map is made, a computer plan is generated to show the best place to put radioactive seeds in and around the prostate. This is often done before or during a prostate implant procedure.