Radiation Therapy
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Radiation Therapy

Reviewed by: Kate M. Cronan, MD

What Is Radiation?

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. Radiation 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.

What Is Cancer?

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 and make someone very sick. When these cells form a mass (or lump), it is called a tumor (say: TOO-mer).

Tumors can be:

  • benign (say: bih-NINE), which means they aren't cancer
  • malignant (say: muh-LIG-nent), which means they are cancerous

Both adults and kids can get cancer, but kids don't get it very often.

Why Is Radiation Used to Treat Cancer?

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 along with chemotherapy or surgery. Chemotherapy (say: kee-mo-THER-uh-pee) is a treatment that uses medicine to destroy cancer cells. Each person's treatment depends on the kind of cancer he or she has.

A doctor called an oncologist (say: on-KAHL-uh-jist) will make the decision about whether radiation therapy is best for the patient.

Radiation therapy can be given in two ways:

  1. Radiation can be directed to the outside of the body. This is called external radiation therapy.
    or
  2. Doctors may place radioactive material directly into the tumor inside the body. This is called internal radiation therapy.

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

What Happens During External Radiation Therapy?

External radiation therapy uses a large machine and special equipment to aim the right amount of radiation at the tumor. A radiation therapist knows exactly which area of the body will get the treatment. So 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.

Then, the machine is positioned to deliver the exact amount of radiation needed to kill the cells. During treatment, the person has to lie still.

People getting 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. But 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.

What Are Side Effects?

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 depend on the location of the radiation and the dose (how much radiation the patient gets).

Side effects can include hair loss, rash, nausea, vomiting, and diarrhea. Also, a person's mouth and throat can get sore, which can be treated with a type of mouthwash prescribed by the doctor. All of these side effects get better as the effects of the radiation wear off.

What Can Help Me Feel Better?

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 others on the kid's health care team can answer questions and help the kid feel comfortable.

Here are some more tips to help a kid feel better during treatment:

  • Get plenty of sleep.
  • Try to eat healthy meals and drink plenty of liquids.
  • Ask the doctor about medicine to help with any side effects.
Reviewed by: Kate M. Cronan, MD
Date reviewed: December 2018