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Radiation Therapy Process

Radiation Therapy procedure

Radiation therapy (RT), including proton therapy, is used to destroy tumor cells to help control your child’s cancer. The doctors who treat cancer with radiation are called radiation oncologists.

The radiation oncologist and other members of the radiation oncology team will talk with you about the best type of therapy for your child’s cancer and answer any questions you have about the treatment process, including follow up.

Your child’s treatment process will include:


During consultation, you will meet many members of your treatment team, including physicians, nurses, child life specialists and the clinical research staff. They will help answer any questions you have about the process.

Your treatment team will talk to you about informed consent. This is a process for giving permission before treatment can start. They will explain the goal of radiation treatment and any side effects your child may have. 


This is the treatment-planning process. During simulation, your child will have a CT scan and sometimes an MRI to show exactly where the tumor is. The radiation team may do several things to make sure the exact places get treated each time.

  • A staff member may put marks on your child’s skin with permanent marker or paint pen to make it easy for the radiation oncologist to know where to aim each time. You may wash the area gently but do not scrub. Scrubbing can remove the marks and can also irritate your child’s skin.
  • Instead of the marker, the therapist may place very small tattoos (freckle size) on your child’s skin using a very small, sterilized needle.
  • Your child may be fitted for a device to help keep him or her in the same position during each treatment. For instance, a mask or body mold might be made for your child. The therapist may put marks on the mask, too. This helps guide the radiation to the tumor and avoid the healthy tissue.

A physicist and radiation oncologist will plan the amount of radiation and map the radiation beams. 


Because radiation can harm healthy cells along with cancer cells, the radiation must be aimed in exact spots to target the tumor. This means your child’s body must be in precise position during radiation treatments. The correct position can help kill more cancer cells while doing as little damage as possible to normal cells. The radiation oncologists will explain to your child that it’s important to be still during the treatment so they can pinpoint the radiation to the exact placement of the tumor. An anesthesiologist may also be part of your child’s treatment team. They will help your child be comfortable and still during therapy.

Your child will get radiation as an outpatient. How often and for how long your child will need radiation depends on the type of cancer.

Your child’s radiation oncologist will explain:

  • About how long each radiation treatment will take (getting the child into the right position takes much longer than the treatment).
  • How long radiation treatment will last—the total number of treatments your child may have (a common schedule is 4 to 5 days a week for several weeks. Small daily doses help protect the skin.)
  • How many “rest” days there will be between your child’s treatments (commonly, your child won’t get RT on the weekends. This time off helps healthy cells recover.)

There will be someone on your child’s treatment team called a scheduler who will work with you to make these radiation appointments.

Follow-up Visits

After treatment, your child’s radiation oncologist will meet with you for follow-up visits. This will help monitor the success of treatment and to look for any possible side effects.


Additional Resources

Refer a Radiation Therapy Patient

Patient Referrals