Radiation Therapy for Sarcoma in Children

During radiation therapy, energy beams penetrate the skin, destroying cancer cells in the body. Our doctors sometimes recommend radiation therapy, along with surgery or chemotherapy, for children with sarcomas, particularly for those whose tumors cannot be removed completely by surgery.

Your child’s doctor may use radiation therapy to shrink tumors in the arm or leg, making them easier to remove during limb-sparing surgery. This treatment may also be used if surgically removing the tumor might cause disfigurement or the loss of an important organ, such as the bladder or an eye.

Radiation therapy can also be used to treat cancer that has spread to other parts of the body, such as the lymph nodes, the small immune system organs that trap viruses and bacteria.

Our radiation oncologists typically use one of four types of radiation therapy to treat childhood sarcomas.

External Beam Radiation Therapy

The most commonly used type of radiation, this therapy delivers high-energy X-ray radiation from a machine to treat tumors. During therapy, your child lies on a table that slides into a machine. Depending on the type and location of the tumor, the treatment typically takes 20 to 30 minutes.

This outpatient therapy requires daily sessions, five days a week for five to six weeks, depending on the type and size of the tumor. Younger children may require sedation or general anesthesia to help them keep still during therapy. Because this type of radiation treatment is not targeted, healthy tissue may also be affected and side effects can occur.

Proton Therapy

This targeted therapy delivers high doses of focused radiation directly to the tumor without damaging surrounding tissue in the body. In proton therapy, positively charged particles called protons are accelerated to rapid speeds—nearly two-thirds the speed of light—and aimed toward cancer cells to damage their DNA, causing them to die. Because proton therapy provides targeted radiation, your child’s doctor may recommend it when the tumor is close to vital organs.

This procedure is typically performed 30 to 90 minutes daily, 5 days a week, for 1 week to 2 months, depending on the tumor’s type and size. Young children who need help lying still may require general anesthesia.

Intensity Modulated Radiation Therapy

During intensity modulated radiation therapy, or IMRT, beams of high-energy X-ray radiation of varying intensities are manipulated to conform to the shape of the tumor. Because this is a targeted therapy, higher doses of radiation can be delivered directly to the tumor, minimizing the damage to surrounding tissue.

This 20- to 30-minute radiation therapy requires daily sessions, 5 days a week, for 5 to 6 weeks, depending on the type and size of the tumor. Younger children may require sedation or general anesthesia to help them keep still during the treatments.


During brachytherapy, doctors treat cancer by implanting radioactive substances called capsules or seeds into or next to a tumor. Sometimes the seeds are implanted in the area where the tumor was removed to prevent it from returning. Because the radiation is designed to target the tumor, there is less damage to surrounding tissue, minimizing side effects. Brachytherapy is used only occasionally to treat sarcomas.

Managing Side Effects

Most types of radiation can affect healthy tissue, causing short-term side effects, including fatigue and red, burning skin that peels easily. Other side effects include nausea and vomiting.

Our specialists can help your child cope with side effects through our medical, emotional, and psychological support services.

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