More than half of all people with cancer are treated with radiation therapy, a type of cancer treatment that is used to shrink tumors and stop the growth of cancer cells. Keep reading to get the facts on radiation therapy, including what it is, what to expect, and how to cope with side effects.

What Is Radiation Therapy?

Cancer is a disease that causes cells to grow abnormally and out of control. In radiation therapy, high-energy X-rays are directed at a person's body to kill cancer cells and keep them from growing and multiplying.

Most people have been exposed to radiation in the form of an X-ray — most likely at a dentist's office. And just like the X-rays given in the dentist's office, radiation therapy is painless. But unlike a typical X-ray, the radiation isn't used just to create a picture of a tooth or broken bone. Radiation therapy delivers higher doses of radiation so that the radiation will kill cancer cells and shrink tumors.

While it's killing the cancer, radiation therapy also can damage normal cells. The good news is that normal cells are more likely to recover from the effects of radiation. Doctors take precautions to protect a person's healthy cells when they're giving radiation treatments.

How Is Radiation Given?

Doctors can give people with cancer radiation therapy as the only form of treatment. Or they may use a combination of radiation therapy and chemotherapy (a treatment that uses medications or chemicals to destroy cancer cells) to fight the cancer. Other people with cancer may have surgery to remove tumors or cancer cells first and then have radiation therapy. Each person's situation and treatment is different. A person who has cancer will see an oncologist (pronounced: on-kah-luh-jist), a doctor who specializes in cancer treatment.

A radiation oncologist is a doctor whose specialty is using radiation to treat cancer. The radiation oncologist will work with other health care professionals to decide on the type and dose of radiation therapy that will best treat a person's cancer.

Radiation therapy can be given two ways — externally, through the skin, or internally, through injection or by implanting a radioactive pellet in the body. Internal radiation therapy is very rare in teens — it's usually adults who get this form of treatment.

With external radiation therapy, doctors use a large machine and special equipment that aims specific amounts of radiation directly at the cancer.

What Happens During External Radiation Therapy?

People who are having external radiation treatments usually don't need to stay in the hospital overnight. They usually visit the hospital or treatment center 5 days a week (with weekends off) for 2 to 8 weeks. Getting small daily doses of radiation helps to protect the normal cells from damage. The weekend breaks help the normal cells to recover from radiation.

If you're being treated using external radiation therapy, at each appointment, you'll dress in a hospital gown or robe and enter the radiation treatment room. After settling you into position on a table or other flat surface, the radiation therapist will leave the room (just as an X-ray technician does when you're having an X-ray at the dentist or hospital). Then a large machine called a simulator will deliver the exact amount of radiation necessary to kill the cancer cells in the area, which has usually been outlined with ink or a faint tattoo.

It usually takes only a few minutes for a teen to receive the daily dose of radiation. While the simulator is on, you'll have to lie very still so the radiation is directed to the right place on your body.

You don't have to worry that you'll glow in the dark after radiation treatment: People who receive external radiation are not radioactive. You'll be able to have normal contact with family and friends after you leave the treatment room.

Common Side Effects of Radiation Therapy

Although radiation therapy is painless, it is powerful, and people who receive it might have some problems during and after treatment. These problems (called side effects) are different from person to person, depending on age, the type of treatment, and where the cancer is located. For example, some people who have radiation therapy may feel more tired than usual, not feel hungry, or lose their hair.

Some of the more common side effects of radiation therapy include:

• Fatigue. Fatigue, or feeling tired, is the most common side effect of radiation treatment, both during treatment and after. You may feel tired for up to 6 weeks after radiation therapy has ended.
• Skin damage or changes. The skin around the treatment area may be red, sensitive, or easily irritated in the days, weeks, and months during and after treatment. The skin may swell or droop or the texture may change. (Most symptoms of skin damage are temporary, although a person may get permanent changes in skin tone or texture.)
• Hair loss. People who receive radiation therapy to the head and neck can lose their hair. Usually, their hair will grow back within 3 months after radiation treatment ends.
• Sore mouth and tooth decay. If you received radiation therapy to the head and neck, your mouth might be sore and sensitive and you may get more cavities. Your doctor may prescribe a mouth rinse to reduce pain. To help reduce these side effects, see the dentist during radiation therapy.
• Stomach and digestive problems. If you receive radiation treatment to the pelvis or abdomen, you might feel sick to your stomach, not feel like eating, have diarrhea, or throw up after radiation treatment. Some people who receive radiation therapy to the head and neck can also experience nausea and vomiting.
• Blood changes. Radiation therapy can kill the germ-fighting cells in the blood. This may temporarily make it harder for a person's body to fight off infection and may increase the need for blood transfusions.

Depending on how old someone receiving radiation therapy is, there may be some long-term side effects. Some people may notice they're not growing as fast as their friends. This happens because normal tissues, especially areas that are still growing, might be damaged during radiation treatments.

Teens who receive radiation to the pelvic or abdominal region might have problems having children later in life, although doctors do everything they can to prevent this. Some people who have had radiation therapy can also be more likely to develop a second cancer later in life. Anyone who has been successfully treated for cancer should be extra careful to have regular checkups and avoid smoking and sun exposure.

It's important to tell a nurse or doctor about any side effects so they can help treat the problem. If you're receiving radiation therapy as a cancer treatment, your doctors will work to cure you, but they'll also want you to be as comfortable as possible while you're being treated.

What Can I Expect After Radiation Treatment?

Although radiation therapy itself doesn't hurt, it can be scary to think about. If you want, talk to your doctor about taking a tour of the hospital or radiation treatment center. Meeting the radiation technologists who will be helping you every day and seeing the radiation equipment may help you feel more comfortable during treatment. Many hospitals set up routine treatment planning visits to prepare patients for treatment. These include a tour of the facilities and an opportunity to ask questions.

In a lot of hospitals, you can talk to a parent or the radiation therapist on an intercom during external radiation treatment. Someone will always be watching you during treatment, and the machine can be stopped at any time if there's a problem. Some treatment centers even provide closed-circuit TVs so your parent can watch you during the procedure.

As you go through radiation treatment, you may feel like you're all alone — but you're not. Your parent, friends, doctors, nurses, psychiatrists, psychologists, social workers, and other members of the cancer treatment team are there to reassure you before, during, and after radiation therapy.

Friends make you feel good when you're healthy — so surrounding yourself with your buds when you're sick is sure to be a pick-me-up. If you're too tired to head to the mall after school, plan a video-fest at your place instead. Sometimes people worry that their friends will feel weird or uncomfortable around them. A parent, nurse, or counselor may be able to give you tips on how to help with this situation.

Many camps, support groups, and other activities are available to teens with cancer. Your nurse or hospital social worker can help you find these opportunities. Who knows? Your treatment for cancer might lead you to a lifelong friend.

In addition to coping with the many emotions you'll feel, you have to deal with the physical stuff, too. Try these tips for chilling out more comfortably during treatment:

• Sleep long, sleep often. Your body needs plenty of rest to recover from radiation and to keep up with basic activities. So scale back on strenuous stuff, and make time to get a good night's sleep every night. Opportunities to get your family to wait on you hand and foot don't come along often!
• Focus on good nutrition. Your appetite may be in the toilet from all that nausea, vomiting, and diarrhea, so try to eat foods that are high in nutrients. Also, eat a balanced diet to prevent weight loss. Several small meals might be easier to eat than a fewer larger ones — you may find it helps to eat every few hours so you don't get too hungry. At times when your stomach is upset, try foods like crackers, toast, broth, and juice pops.
• If you're frequently sick to your stomach, ask your doctor about anti-nausea medicine.
• Get your doctor's OK before taking any medications, including herbal medicines or over-the-counter drugs.
• Wear loose-fitting, soft clothes, especially around the treatment area. This can help you feel more comfortable, so dig those sweatpants out of the closet or ask the radiation tech if you can borrow some scrubs!
• Your skin is more sensitive to sunlight during and after radiation treatment. Avoid exposing the treated area to the sun during the weeks you're getting radiation therapy. And when the treatment's over, wear an SPF 30 sunscreen on the treated area.
• If you lose your hair because of radiation therapy, protect your head from sun exposure and irritation by wearing soft hats or scarves.
• Wash sensitive areas of skin gently using only lukewarm water — no soaps or skin products, including creams and lotions, until you get your doctor's OK. Pat your skin dry after bathing. If your skin is itchy and irritated, your doctor may prescribe ointments or cream to speed healing and reduce irritation.

Once you've finished radiation treatment, it's still important to visit the doctor for follow-up appointments. During these checkups, the doctor will want to know how you're feeling, whether you're having any continuing side effects, and whether there are any signs of the cancer coming back.

Undergoing treatment for cancer can be time-consuming, scary, and sometimes painful — both for the teens going through it and their friends and families. The good news is that radiation therapy can be an effective cancer fighter that enables many people to go on to live healthy, full lives.

Reviewed by: Donna Patton, MD
Date reviewed: May 2010