Proton Radiation Therapy (RT) for the Treatment of Pediatric Rhabdomyosarcoma

* A special device is made for each participant to help them hold still during the treatment. This may be in the form of a mask or a custom made foam cradle depending on the area to be treated. * Radiation treatments will be given once per day, 5 days a week for a total of 4 to 6 weeks, depending upon how much total dose the tumor requires. * Participants will be seen once per week by their radiation doctor to monitor health and record any side effects from treatment. * After the radiation treatments are completed, participants will be required to undergo further tests and evaluations for several years following treatment.