Overview & Description
Radiation therapy involves the use of radioactive waves to treat certain types of cancer. The therapy can be given with external beams of radiation or brachytherapy. External-beam radiation directs radioactive waves at targeted portions of the body. Brachytherapy involves an implant of radioactive material inside the body.
Radiation affects molecules, proteins, and DNA in cells. The cells become damaged and are unable to function and divide normally. Cancer cells are more susceptible to radiation because they can't repair the damage. Some cancers are considered "radiosensitive" and curable with radiation. Other cancers are resistant to radiation.
cancer of the cervix
cancer of the larynx
germ cell cancer
Hodgkin's lymphoma
prostate cancer
Other cancers are treated with radiation to improve symptoms, not to cure the person. These include:
breast cancer
colorectal cancer
lung cancer
melanoma, which is a skin cancer
The decision to use radiation therapy, and how to use it, depends on a number of factors. Among them are the tissue type and the location and stage of the cancer. The healthcare provider will also consider the person's overall state of health.
Low-energy radiation is also used for a few noncancerous conditions, such as a skin disease known as psoriasis. Total body radiation at low doses is used before bone marrow transplants. It destroys the existing bone marrow and suppresses the immune system.
Electron beams are low energy. They are often used for skin conditions and cancers. High-energy particles can penetrate deeply and are used for brain or deep solid tumors. Higher doses of radiation are used for radiation-resistant cancers and when there is an intent to cure. Lower doses are used for radiosensitive cancers and to relieve symptoms.
Any form of radiation can be combined with chemotherapy. This combination therapy has more benefits and more side effects. Fluorouracil (5-FU), doxorubicin, hydroxyurea, and cisplatin are examples of radiosensitizing chemotherapy medicines. They make the targeted tissue more susceptible to radiation therapy.
Another form of radiation therapy is radioactive iodine. It is swallowed as a liquid and circulates through the body. It is used to treat thyroid cancer. The radioactivity disappears within a few weeks.
The procedure to deliver external-beam radiation is somewhat similar to giving an X-ray. The person is put into position, and the machine delivers the radiation to the desired area. External-beam therapy involves cobalt and protons or electrons. It is given over several minutes, usually once a day for several weeks. The higher the energy, the deeper into the body the radiation can go.
Radiation affects molecules, proteins, and DNA in cells. The cells become damaged and are unable to function and divide normally. Cancer cells are more susceptible to radiation because they can't repair the damage. Some cancers are considered "radiosensitive" and curable with radiation. Other cancers are resistant to radiation.
Who is a candidate for the procedure?
Because it works so well, radiation is now used in at least half of all individuals with cancer. Many cancers can be cured solely with radiation therapy. These include:Other cancers are treated with radiation to improve symptoms, not to cure the person. These include:
The decision to use radiation therapy, and how to use it, depends on a number of factors. Among them are the tissue type and the location and stage of the cancer. The healthcare provider will also consider the person's overall state of health.
Low-energy radiation is also used for a few noncancerous conditions, such as a skin disease known as psoriasis. Total body radiation at low doses is used before bone marrow transplants. It destroys the existing bone marrow and suppresses the immune system.
How is the procedure performed?
Radioactive implants can be placed anywhere inside the body. Implants may use wires or rods that are placed at the site of the tumor. They may contain radioactive cesium, radium, or iridium. The implants can remain in place for several hours to several days. They are removed after the dose of radiation has been delivered. They do not hurt and are not generally noticeable once they are in the body.Electron beams are low energy. They are often used for skin conditions and cancers. High-energy particles can penetrate deeply and are used for brain or deep solid tumors. Higher doses of radiation are used for radiation-resistant cancers and when there is an intent to cure. Lower doses are used for radiosensitive cancers and to relieve symptoms.
Any form of radiation can be combined with chemotherapy. This combination therapy has more benefits and more side effects. Fluorouracil (5-FU), doxorubicin, hydroxyurea, and cisplatin are examples of radiosensitizing chemotherapy medicines. They make the targeted tissue more susceptible to radiation therapy.
Another form of radiation therapy is radioactive iodine. It is swallowed as a liquid and circulates through the body. It is used to treat thyroid cancer. The radioactivity disappears within a few weeks.
The procedure to deliver external-beam radiation is somewhat similar to giving an X-ray. The person is put into position, and the machine delivers the radiation to the desired area. External-beam therapy involves cobalt and protons or electrons. It is given over several minutes, usually once a day for several weeks. The higher the energy, the deeper into the body the radiation can go.
Preparation & Expectations
What happens right after the procedure?
Some medicines may be used to relieve acute or late side effects. However, they may not be very effective. Corticosteroids, such as prednisone, can reduce damage to healthy organs. People can often go home after the procedure if they have no other reason to stay in the hospital.People who receive external-beam therapy do not put others at risk. They are not radioactive during or after treatment. Patients who have the implants can emit radiation. Precautions are taken to prevent other people from being exposed.
Home Care and Complications
What happens later at home?
Radiation therapy can lessen the symptoms of cancer. These include pain, numbness, headaches, and nerve problems.Radiation treatment with intent to cure delivers a tolerable dose. People who are cured can live healthy lives. They can be treated again at the same site if a relapse occurs.
Almost all cancers treated with radiation require monitoring for a return of the cancer. Monitoring may last for 2 to 10 years, depending on the type of cancer.
What are the potential complications after the procedure?
Side effects occur because any living tissue is sensitive to radiation. They may be acute, mild, and temporary. Other times, they can be more serious and permanent. Normal cells that are rapidly growing or regenerating are more prone to side effects. Examples are bone marrow, intestines, kidneys, liver, and lungs. The brain, heart, and bone are less sensitive.Some side effects are acute but go away on their own. These include:
Other side effects can develop more slowly and are permanent. These include necrosis or death of bone, and pneumonitis, an irritation of the lungs. Later side effects may also include:
Radiation to the brain can cause delayed cognitive impairments. These may include personality changes, memory loss, and dementia.
Combining radiation and chemotherapy can cause more acute and late side effects. Combination therapy is more likely to cause secondary cancers and permanent damage to the bone marrow.
Superficial electron-beam radiation is usually free of serious side effects. Implanted radiation tends to cause local reactions. There can be some late complications, such as scarring. Radioactive iodine in the usual doses rarely causes any problems.
Attribution
Author:Miriam P. Rogers, EdD, RN, AOCN, CNS
Date Written:
Editor:Crist, Gayle P., MS, BA
Edit Date:08/31/01
Reviewer:Adam Brochert, MD
Date Reviewed:07/27/01
Date Written:
Editor:Crist, Gayle P., MS, BA
Edit Date:08/31/01
Reviewer:Adam Brochert, MD
Date Reviewed:07/27/01
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