大象tv

Radiation therapy uses high-energy rays or particles to kill cancer cells. It is a way to kill cancer cells that cannot be removed with surgery. When radiation is used to help treat osteosarcoma, it is typically given with chemotherapy (chemo).

When might radiation therapy be used?

Osteosarcoma cells are not easily killed by radiation, so radiation therapy does not play a major role in treating many of these cancers. But sometimes radiation can be useful if the tumor cannot be removed completely by surgery.

For example, osteosarcoma can start in hip bones or in the jawbones. In these situations, it is often not possible to remove all the cancer. After as much of the tumor is removed as possible, radiation can be given to try to kill the cancer cells that are left. Chemotherapy is often given after the radiation.

Radiation can also be used to help slow tumor growth and control symptoms like pain and swelling if surgery is not possible, or if the cancer has come back.

How radiation therapy is done

This type of treatment is given by a doctor called a radiation oncologist. Before treatments start, the radiation team must create a treatment plan. The team will take careful measurements with tests such as MRI scans during a session called a treatment simulation. The radiation field, or area where radiation will be given, and the dose will be defined based on these tests.

Radiation is usually given 5 days a week for several weeks. Each treatment is like getting an x-ray, although the dose of radiation is much stronger. For each session, the person lies down on a special table while a machine gives the radiation. The treatment is not painful.

Each session lasts about 15 to 30 minutes. Most of the time for the treatment is spent making sure the radiation is aimed correctly. It is important that radiation is given to the exact field planned in the simulation. Patients may be fitted with a plastic mold that looks like a body cast to hold them in the same spot for each treatment. Younger children may be given medicine to make them sleep so they will not move during treatment.

Types of radiation therapy

Modern radiation therapy techniques help doctors aim the treatment at the tumor more accurately than they could in the past.

The best approach to radiation treatment may be different for everyone and depends on the expertise and equipment available at your treatment center. Ask your care team about the plan for you or your child.

Possible side effects

The side effects of external radiation therapy depend on where the radiation is given, the dose of radiation, and the person’s age. Short-term side effects of radiation occur during or shortly after treatment; long-term side effects can take months or years to develop.

Short-term side effects

• Fatigue
• Hair loss (in the area receiving radiation)
• Skin that may be red, tender, or dry, like a sunburn (in the area receiving radiation)
• Low blood counts (this is more common if you are also getting chemo)
• Mouth sores, trouble swallowing, and/or loss of appetite (from radiation to the head and neck area)
• Nausea, vomiting, cramps, and/or diarrhea (from radiation to the abdomen or pelvis)
• Damage to the bladder, which might cause pain or problems when passing urine (from radiation to the abdomen or pelvis)

Long-term side effects

Radiation, especially in young children, can affect how bones and tissues grow. Children who have been treated with radiation should be watched closely as they age, since radiation could result in hormone changes or a failure to grow to full adult height. If radiation is given to an arm or leg, scarring may lead to limb length differences or limited movement that may need treatment.

Many of the long-term effects of radiation are specific to where the radiation was given. For example, radiation given to the neck or jaw may affect the thyroid gland or teeth, while radiation to the pelvis could affect fertility. It is best to speak with your radiation team about what specific long-term side effects you may need to watch for.

Because radiation works by breaking DNA, it can also increase the risk of a second cancer many years later. Depending on where radiation was given, early cancer screening may be recommended.

To lower the risk of serious long-term effects from radiation, doctors try to use the lowest dose of radiation therapy that is still effective. Still, it is important to go to  follow-up visits with your (child’s) doctor so that if problems come up, they can be found and treated as early as possible.

Radioactive drugs (radiopharmaceuticals)

Bone-seeking radioactive drugs, such as samarium-153-EDTMP (Quadramet) or radium-223 (Xofigo), can be used to slow tumor growth and treat symptoms, such as pain, in people with advanced osteosarcoma. These drugs are injected into a vein and collect in the bones. Once there, the radiation they give off kills the cancer cells.

These drugs are especially helpful when cancer has spread to many bones, since external beam radiation would need to be aimed at each affected bone. In some cases, these drugs are used together with external beam radiation aimed at the most painful bone metastases.

The major side effect of these drugs is a lowering of blood cell counts, which could increase the risk for infections or bleeding, especially if the blood counts are already low.