Radiation Therapy

If you've seen a dentist or been treated for a broken bone, you've experienced radiation firsthand. In everyday life, radiation in the form of X-rays is used to create images of areas of the body that doctors can't see, such as the inside of a tooth or the interior of the chest cavity.

In much higher doses, radiation is used to treat cancer. Radiation therapy (also called radiotherapy, irradiation, or X-ray therapy) works by preventing cells from growing or reproducing, and by destroying them. But parents whose kids need radiation therapy — one of the most common treatments for childhood cancer — often have many questions and concerns about it.

About Radiation Therapy

In radiation therapy, high-energy radiation from X-rays, gamma rays, or other sources is used to kill cancer cells and shrink tumors. Some types of childhood cancer treated with radiation therapy include brain tumors, Wilm's tumor, and head and neck cancers.

Besides destroying cancer cells, radiation therapy can also harm normal cells. Normal cells are more likely to recover from its effects, though, and your child's health care team will take extensive measures to carefully monitor radiation doses to protect healthy tissue.

Because every case is different, each child's cancer treatment will also be unique. Some kids receive radiation therapy alone, while others need both radiation and chemotherapy (the use of medicines to destroy cancer cells). And some kids require radiation therapy and surgery to remove tumors or cancerous areas.

How Radiation Is Given

Radiation therapy is administered two ways: externally or internally. Some kids may receive both external and internal radiation, depending on their needs.

External radiation therapy uses a large machine and special equipment that aims very specific amounts of radiation at cancerous tumors or diseased areas of the body. With Internal radiation therapy (also known as brachytherapy, interstitial therapy, or implant therapy), a radioactive substance is injected or implanted into the body at the site of the tumor or cancer cells. In some cases, the material is swallowed.

Most kids receive only external radiation therapy, although those with cancers of the head and neck, uterus, cervix, thyroid, and testes may also undergo internal radiation therapy.

A radiation oncologist (a doctor who specializes in radiation therapy) will work with other health care professionals to decide on the type and dose of radiation therapy that's best for your child.

What Happens During Radiation Therapy

External Radiation

Receiving radiation therapy for cancer treatment isn't a one-time deal: Kids who receive external radiation usually visit the hospital or treatment center as outpatients 4 to 5 days a week for several weeks, coming in just for the treatment and going home right after. Receiving small daily doses of radiation helps to protect the normal cells from damage, and weekend breaks help the normal cells to recover from the trauma of radiation.

Before the first radiation treatment, a planning session called simulation will help you prepare. Your child will lie on an X-ray table while a radiation therapist uses an X-ray machine (called a simulator) to define the treatment area. Some X-rays or CT scans might be taken, and an area on the skin is marked with ink to highlight the treatment area. This "tattoo" should not be wiped off because it helps to position the radiation for each treatment.