Radiation Oncology

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External Radiation Therapy: What to Expect

The radiation used in radiation therapy can come from a variety of sources. Your doctor may choose to use x-rays, or an electron beam. Choosing which type of radiation to use depends on what type of cancer you have and on how deep into your body the doctor wants the radiation to penetrate. High-energy radiation is used to treat many types of cancer. Low-energy x-rays are used to treat some kinds of skin diseases.

After a physical exam and a review of your medical history, the radiation oncologist may need to do some special planning to pinpoint the treatment area. In a process called simulation, you will be asked to lie very still on a table while the radiation therapist uses a special x-ray machine to define your treatment port or field. For planning of three-dimensional conformal therapy, a CT scanner is used for this process. This is the exact place on your body where the treatment will be aimed. You may have more than one treatment port. Simulation may take from a half-hour to about 2 hours.

The radiation therapist often will mark the treatment port on your skin with tiny dots of colored, semipermanent ink to outline the treatment area. Be careful when you bathe because the marks must not be washed off until all of your treatment is over. If they start to fade, tell the therapist who will darken them so that they can be seen easily. Do not try to draw over faded lines at home unless they will be completely gone before your next visit. If you do replace the marks, be sure to tell the therapist at your next visit.

Using the information from the simulation, other tests, and your medical background, your doctor will meet with the radiation physicist and the dosimetrist. Your doctor then decides how much radiation is needed, how it will be delivered, and how many treatments you should have. This process often takes several days.

After you have started the treatments, your doctor will follow your progress, checking your response to treatment and your overall well-being at least once a week. The treatment plan may be revised by your doctor, if needed. It's very important that you have all of your scheduled treatments to get the most benefit from your therapy. Unnecessary delays can lessen the effectiveness of your radiation treatment

How Long Does the Treatment Take?

Radiation therapy usually is given 5 days a week for 6 or 7 weeks. When radiation is used for palliative care, the course of treatment lasts for 2 to 3 weeks. These types of schedules, which use small amounts of daily radiation, rather than a few large doses, help protect normal body tissues in the treatment area. Weekend rest breaks allow normal cells to recover. The total dose of radiation and the number of treatments you need will depend on the size and location of your cancer, type of tumor, your general health, and any other treatments you're receiving.

What Happens During Each Treatment Visit?

Before your treatment is given, you may need to change into a hospital gown or robe. It's best to wear clothing that is easy to take off and put on again.  In the treatment room, the radiation therapist will use the marks on your skin to locate the treatment area. You will sit in a special chair or lie down on a treatment table. For each external radiation therapy session, you will be in the treatment room about 15 to 30 minutes, but you will be getting your dose of radiation for only about 1 to 5 minutes of that time. Receiving external radiation treatments is painless, just like having an x-ray taken.

The radiation therapist may put special shields (or blocks) between the machine and certain parts of your body to help protect normal tissues and organs. There might also be plastic or plaster forms to help you stay in exactly the right place. You will need to remain very still during the treatment so that the radiation reaches only the area where its needed and the same area is treated each time. You don't have to hold your breath--just breathe normally

The radiation therapist will leave the treatment room before the machine is turned on. The machine is controlled from a small area that is nearby. You will be watched on a television screen or through a window in the control room. Although you may feel alone, keep in mind that you can be seen and heard at all times by the therapist who can talk with you through a speaker.

The machines used for radiation treatments are very large, and they make noises as they move around to aim at the treatment area from different angles. Their size and motion may be frightening at first. Remember that the machines are being moved and controlled by your radiation therapist. They are checked constantly to be sure they're working right. If you are concerned about anything that happens in the treatment room, ask your therapist to explain.

You will not see or hear the radiation, and, most likely, you won't feel anything. If you do feel ill or very uncomfortable during the treatment, tell your therapist at once. The machine can be stopped at any time.

What is Hyperfractionated Radiation Therapy?

Radiation is usually given once a day in a dose that is based on the type and location of the tumor. In hyperfractionated radiation therapy, the daily dose is divided into smaller doses that are given more than once a day. If more than one treatment is given per day to an area, the treatments usually are separated by 4 to 6 hours. Doctors are studying hyperfractionated therapy to see if it is equally or even more effective than once-a-day therapy. Early results in certain tumors are encouraging, and hyperfractionated therapy is becoming a more common way to give radiation treatments.

What are the 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 of your treatment. Even hugging, kissing, or having sexual relations with others poses no risk to them of radiation exposure.

Side effects of radiation therapy most often are related to the area that is being treated. Your doctor and nurse will tell you about the possible side effects 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 unusual pain. Most side effects that occur during radiation therapy, although unpleasant, are not serious and can be controlled with medication or diet. They usually go away within a few weeks after treatment ends. However, some side effects can last longer. Many patients have no side effects at all. In another section "Managing Side Effects," you will find advice on how to cope with the side effects that might occur during and after your therapy.

Throughout your treatment, your radiation oncologist 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 discomforts you may have had, especially after your treatment is completed. You may continue to notice more improvements with time. Your doctor probably will recommend some tests to be sure that the radiation is causing as little damage to normal cells as possible. You may have routine blood tests to check the levels of white blood cells and platelets, which may be lower than normal during treatment.

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 the doctor must plan, and sometimes adjust, your treatment just for you. In addition, your doctor or nurse will give you advice for caring for yourself at home that is specific for your treatment and the side effects that might result.

Nearly all cancer patients receiving radiation therapy need to take special care of themselves to protect their health and help the treatment succeed. Some guidelines to remember are given below:

• Be sure to get plenty of rest. Sleep as often as you feel the need. Your body will use a lot of extra energy over the course of your treatment, and you may feel very tired. In fact, fatigue may last for 4 to 6 weeks after your treatment is finished.
  
• Good nutrition is a must. Try to eat a balanced diet that will prevent weight loss. For patients who have problems with eating or diet planning, the section titled "Managing Side Effects" offers practical tips.
• Avoid wearing tight clothes such as girdles or closefitting collars over the treatment area. It's best to wear older garments that feel comfortable and that you can wash or throw away if the ink marks rub off on them.

Be extra kind to the skin in the treatment area.

• Do not use any soaps, lotions, deodorants, medicines, perfumes, cosmetics, talcum powder, or other substances in the treated area without talking with your doctor.
• Wear loose, soft cotton clothing over the treated area.
• Do not starch your clothes.
• Do not rub or scrub treated skin.
• Do not use adhesive tape on treated skin. If bandaging is necessary, use paper tape. Try to apply the tape outside of the treatment area.
• Do not apply heat or cold (heating pad, ice pack, etc.) to the treatment area. Even hot water can hurt your skin, so use only lukewarm water for bathing the treated area.
• Use an electric shaver if you must shave the area-- but only after checking with your doctor or nurse. Do not use a preshave lotion or hair remover products.
• Protect the area from the sun. If possible, cover treated skin (with light clothing) before going outside. Ask your doctor if you should use a lotion that contains a sunblock. If so, use a PABA sunscreen or a sunblocking product with a protection factor of at least 15. Reapply the sunscreen often, even after your skin has healed following your treatment. Continue to protect your skin from sunlight for at least 1 year after radiation therapy.
• Be sure your doctor knows about any medicines you are taking before starting treatment. If you need to start taking any medicines, even aspirin, let your doctor know before you start.
• Ask your doctor, nurse, or radiation therapist any questions you have. They are the only ones who can properly advise you about your treatment, side effects, at-home care, and any other medical concerns you may have.