(Radioterapia)

What do you think of when you hear the word radiation? Do you think of getting X-rays of your teeth or a broken bone? Or do you think of something dangerous?

Radiation (say: ray-dee-ay-shun) is tricky to understand because you can't see it. It's a process in which energy is given off in the form of particles or rays. For example, the sun emits a kind of radiation.

Radiation is everywhere — in soil, water, food, building materials, and even our own bodies. Too much of it can be harmful, but in the right amounts, radiation has many uses. It can be used to make X-rays, create electricity, and even power submarines.

And radiation therapy is one form of treatment for kids or adults who have cancer. Both adults and kids can get cancer, but kids don't get it very often.

Cancer is a disease that causes normal cells in the body to grow out of control. If left untreated, these cells can grow throughout the body, making the person very sick. Radiation therapy kills cancer cells and keeps them from growing and multiplying. The fewer cancer cells, the better, because then a person can start feeling well again.

How Is Radiation Given?

Cancer can be treated with radiation therapy alone or in combination with chemotherapy or surgery. Chemotherapy (say: kee-mo-ther-uh-pee) is a treatment that uses medicine to destroy cancer cells. Some people may first have surgery to remove cancer cells or tumors and then have radiation therapy. Each person's treatment depends on the kind of cancer he or she has.

A doctor called an oncologist (say: on-kahl-oh-jist) will make the decision about whether radiation therapy is best for the patient. Sometimes people stay in the hospital to get radiation therapy, but in most cases, the patient comes to the hospital or doctor's office for treatment and goes home afterward.

Radiation therapy can be given in two ways. A person may receive radiation directed to the outside of the body called external radiation. Or a person may receive radiation therapy that places the radiation inside the body, which is called internal radiation therapy (putting radioactive material directly in the tumor).

Some people may receive both types of radiation therapy, but internal radiation is rarely used to treat the kinds of cancer kids get.

What Happens During Radiation Therapy?

Because the radiation treatment needs to be just right, the patient must go through a simulation first. During this process, the person lies on an X-ray table while the radiation therapist uses a special machine called a simulator to define the treatment area.

When the therapist knows exactly which area of the body will get the radiation treatment, he or she marks it with ink. This "tattoo" should not be wiped off because these spots help to position the radiation for each treatment.

At each appointment, a large machine is positioned to deliver the exact amount of radiation necessary to kill the cells. It usually takes only a few minutes for a person to receive the daily dose of radiation. During a radiation treatment, a person has to lie still.

People who are having external radiation therapy usually visit the hospital on weekdays for several weeks. These doses of radiation are small, but they are strong enough to kill cancer cells. The radiation also can damage normal cells. Weekend breaks from radiation treatments give normal cells a chance to recover and let new, healthy cells grow.

How Does Radiation Therapy Make a Person Feel?

Getting a radiation treatment doesn't hurt and you do not see, smell, or feel the radiation. But these treatments can cause some temporary health problems called side effects. The kinds of side effects experienced by the patient depend on the location of the radiation and the dose, or how much radiation the patient receives.

Common side effects include hair loss, rash, nausea, vomiting, and diarrhea. All of these side effects get better as the effects of the radiation wear off.

For a kid getting radiation therapy, it's normal to feel a little nervous. One important thing to remember is that a kid's parents will be there to help. Also, doctors, nurses, and other health care workers can answer questions and help patients feel comfortable.

It's a good idea to visit the center where the treatment will be done, so the patient can see the place and meet the people who work there. Here are some more tips to help a person feel better during treatment:

• Get plenty of sleep.
• Try to eat healthy meals and drink plenty of fluids.
• Ask the doctor about medicine to help with nausea and stomach upset.
• Keep affected skin protected from the sun and ask about getting a special cream if a rash develops.

After the radiation treatments, patients visit the doctor for follow-up care. In many cases, the person will be well on the way to being cancer free.

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