External Radiation Therapy, Part 2

by National Cancer Institute

(Page 3 of 9)

IMPROVING RADIATION TREATMENT

Researchers in the field of radiation therapy continue to seek ways to improve the outcome of treatment. Their challenge is to get a high dose of radiation to the tumor while the surrounding normal tissue is protected from radiation damage. New methods for using radiation to treat cancer are being investigated. Many are promising but they are not yet widely available. You may hear the following terms that describe some of these new methods of radiation treatment:

Three-dimensional conformal radiation therapy is a radiation technique that is being used in some cancer centers. Computer simulation produces an accurate image of the tumor and surrounding organs so that multiple radiation beams can be shaped exactly to the contour of the treatment area. Because the radiation beams are precisely focused, nearby normal tissue is spared. This technique is being used to treat prostate cancer, lung cancer, and certain brain tumors.

Stereotactic radiosurgery, which uses gamma rays or a linear accelerator, is useful for treating certain kinds of brain tumors and some malformations in the brain's blood vessels. One technique uses many powerful, precisely focused radiation beams. The patient wears a special helmet to focus the gamma rays and aim them at the target tissue from many directions. The treatment is painless and bloodless and, unlike conventional brain surgery, there is no danger of infection. Other systems use a linear accelerator to deliver the radiation in arcing paths around the patient's head.

Cyberknife is a new, but less common, treatment that is being used to treat brain tumors. This system uses a miniature radiation machine and a robotic arm that moves around the patient's head while delivering small doses of radiation from hundreds of directions. During treatment a computer analyzes hundreds of brain images and adjusts for slight movements by the patient. This makes it possible to deliver the treatment without using a frame to hold the patient's head still. Only the tumor receives the high doses of radiation and healthy tissue is spared.

The Peacock system is a variation of the cyberknife. It uses special machinery that delivers tiny focused beams of radiation while it rotates around the patient's head. The beams continuously change shape and size to conform to the shape and size of the tumor while avoiding vital structures in the brain. Computer software controls the intensity of the radiation.

Precision therapy is a method of radiosurgery recently developed in Sweden. It uses high doses of radiation delivered in fewer fractions than in conventional radiation therapy. An advanced treatment planning system permits precise targeting from many angles. As with other advances in radiation treatment, it allows high doses of radiation to be delivered to tumor tissue while reducing radiation damage to healthy tissue.

What Are the Side Effects of Treatment?

External radiation therapy does not cause your body to become radioactive. There is no need to avoid being with other people because you are undergoing treatment. Even hugging, kissing, or having sexual relations with others poses no risk of radiation exposure.

Most side effects of radiation therapy are related to the area that is being treated. Many patients have no side effects at all. Your doctor and nurse will tell you about the possible side effects you might expect and how you should deal with them. You should contact your doctor or nurse if you have any unusual symptoms during your treatment, such as coughing, sweating, fever, or pain.

The side effects of radiation therapy, although unpleasant, are usually not serious and can be controlled with medication or diet. They usually go away within a few weeks after treatment ends, although some side effects can last longer. In the Managing Side Effects 2 section, you will find advice on how to cope with the side effects that might occur during and after your therapy. Always check with your doctor or nurse about how you should deal with side effects.

Throughout your treatment, your doctor will regularly check on the effects of the treatment. You may not be aware of changes in the cancer, but you probably will notice decreases in pain, bleeding, or other discomfort. You may continue to notice further improvement after your treatment is completed.

Your doctor may recommend periodic tests and physical exams to be sure that the radiation is causing as little damage to normal cells as possible. Depending on the area being treated, you may have routine blood tests to check the levels of red blood cells, white blood cells, platelets; radiation treatment can cause decreases in the levels of different blood cells.

What Can I Do To Take Care of Myself During Therapy?

Each patient's body responds to radiation therapy in its own way. That's why your doctor must plan, and sometimes adjust, your treatment. In addition, your doctor or nurse will give you suggestions for caring for yourself at home that are specific for your treatment and the possible side effects.

Nearly all cancer patients receiving radiation therapy need to take special care of themselves to protect their health and to help the treatment succeed.

Before starting treatment, be sure your doctor knows about any medicines you are taking and if you have any allergies. Do not start taking any medicine (whether prescription or over-the-counter) during your radiation therapy without first telling your doctor or nurse.

Fatigue is common during radiation therapy. Your body will use a lot of extra energy over the course of your treatment, and you may feel very tired. Be sure to get plenty of rest and sleep as often as you feel the need. It's common for fatigue to last for 4 to 6 weeks after your treatment has been completed.

Check with your doctor before taking vitamin supplements or herbal preparations during treatment.

Avoid wearing tight clothes such as girdles or close-fitting collars over the treatment area.

Be extra kind to your skin in the treatment area:

• Ask your doctor or nurse if you may use soaps, lotions, deodorants, sun blocks, medicines, perfumes, cosmetics, talcum powder, or other substances in the treated area.

• Wear loose, soft cotton clothing over the treated area.

• Do not wear starched or stiff clothing over the treated area.

• Do not scratch, rub, or scrub treated skin.

• Do not use adhesive tape on treated skin. If bandaging is necessary, use paper tape and apply it outside of the treatment area. Your nurse can help you place dressings so that you can avoid irritating the treated area.

• Do not apply heat or cold (heating pad, ice pack, etc.) to the treated area. Use only lukewarm water for bathing the area.

• Use an electric shaver if you must shave the treated area but only after checking with your doctor or nurse. Do not use a preshave lotion or hair removal products on the treated area.

• Protect the treatment area from the sun. Do not apply sunscreens just before a radiation treatment. If possible, cover treated skin (with light clothing) before going outside. Ask your doctor if you should use a sunscreen or a sunblocking product. If so, select one with a protection factor of at least 15 and reapply it often. Ask your doctor or nurse how long after your treatments are completed you should continue to protect the treated skin from sunlight.

If you have questions, ask your doctor or nurse. They are the only ones who can properly advise you about your treatment, its side effects, home care, and any other medical concerns you may have.

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