Ewing Sarcoma: Radiation Therapy

What is radiation?

Radiation uses high-energy radiation from X-rays or particles to kill cancer cells.

When might radiation be used?

Radiation is sometimes part of the treatment for Ewing sarcomas. It’s often used with other types of treatment. Although radiation is not usually the main treatment, these tumors often respond well to radiation. There are several reasons your healthcare provider may suggest radiation:

  • To try to shrink a tumor before surgery. This may make it easier to remove. When it’s used before surgery, it’s called neoadjuvant therapy.

  • Instead of surgery as the main treatment. If the healthcare provider doesn't think all of the tumor can be removed safely with surgery, radiation might be used instead.

  • After surgery, especially if the surgeon isn't sure all of the cancer has been removed. 

  • To treat tumors in other parts of the body. If Ewing sarcoma has spread, radiation is often an option to treat cancer that’s reached other organs. 

To plan your child's treatment, you'll meet with a team of cancer specialists. This might include a surgeon, radiation oncologist, and medical oncologist.

What happens during radiation

The most common way to get radiation for Ewing sarcoma is from a machine outside the body that emits invisible X-ray beams. This is called external radiation. Sometimes special types of external radiation are used to try to limit the doses of radiation that reaches nearby normal cells. These include intensity-modulated radiation therapy (IMRT) or proton beam therapy.

A doctor who specializes in cancer and radiation is called a radiation oncologist. This doctor decides the kind of radiation your child needs. He or she also decides the dose and how long your child will need the treatment.

External radiation can often be given on an outpatient basis in a hospital or a clinic. The standard treatment for external radiation is given five days a week for several weeks.

Preparing for radiation

Before your child's first treatment, he or she will have a session to learn exactly where on the body the radiation beam needs to be aimed. The process is called simulation. This session may take up to two hours. During this session, your child may have imaging tests. These may include computerized tomography (CT) scans or magnetic resonance imaging (MRI) scans. This can help healthcare providers know the exact location of the tumor to better aim the radiation. Also at this session, your child may have body molds made. This can help keep him or her from moving during the treatment. Then, he or she will lie still on a table while a radiation therapist uses a machine to define the treatment field. The field is the area where the radiation will be aimed. Sometimes it’s called the radiation port. The therapist may mark your child's skin with tiny dots of semi-permanent ink. This is done so the radiation will be aimed at the exact same place each time. 

On the days your child gets radiation  

On the days your child gets radiation, he or she will lie on a table while the machine is placed over him or her. Your child may have to wear a hospital gown. The experience is much like getting an X-ray, only longer. It takes about 15–30 minutes to do. You should, though, plan on being there for about an hour.

At the start of the treatment session, a radiation therapist may place blocks or special shields to protect parts of the body that don’t need to be exposed to radiation. The therapist then lines up the machine so that radiation is directed to the spot that was marked during the simulation. When your child is ready, the therapist leaves the room and turns the machine on. Your child may hear whirring or clicking noises, like the sounds of a vacuum cleaner, while the radiation is being given. During the session, your child will be able to talk to the therapist over an intercom. You can’t feel radiation, so the process will be painless. Also, your child will not be radioactive afterward.

What to expect after radiation

Because radiation affects normal cells as well as cancer cells, your child may have some side effects from this treatment. The side effects from radiation tend to be limited to the area being treated. Some people have few or no side effects. If your child has them, the healthcare provider may change the dose of radiation or the frequency of treatments. Or the healthcare provider may stop treatment until the side effects are cleared up. Be sure to let your child’s healthcare provider know about any side effects he or she has.

Potential short-term side effects

Common side effects of radiation can include the following:

  • Skin changes in the areas that get radiation. This is like sunburn.

  • Hair loss in areas that get radiation

  • Nausea or diarrhea. This may happen from radiation to the abdomen or pelvis.

  • Bladder irritation. This can lead to a feeling of having to urinate often or to pain or burning during urination. This may happen from radiation to the pelvis.

  • Low blood cell counts

If your child has any of the side effects, talk with the healthcare provider about how to deal with them and how to know when they become serious. These side effects tend to go away a few weeks after treatment.

Potential long-term side effects

Radiation can cause some long-term side effects. These depend on where the radiation was aimed. This is a concern in treating Ewing sarcoma, which often affects children, teens, or young adults.

  • Slowed bone growth. Radiation can slow bone growth in children. This may cause one leg to be shorter than the other, for instance. This isn’t a concern in people whose bones are no longer growing.

  • Second cancers. Cancers are more likely to form in areas that have received radiation. These cancers may form even decades after treatment.

  • Reduced fertility. Radiation to the pelvis can damage reproductive organs. This could affect fertility later in life.

  • Damage to other organs. Organs such as the heart or lungs might be affected by radiation to the chest. The intestines might be affected by radiation to the abdomen.