What is proton therapy?
Proton therapy is an advanced form of radiation therapy that uses protons, which are charged particles from an atom. The advantage of proton therapy over traditional forms of radiation treatment is its ability to deliver a pencil-thin beam of radiation to the tumor area with remarkable precision -- within one millimeter -- that avoids the surrounding tissue, generates fewer side effects and improves tumor control.
Proton therapy requires a highly specialized machine to deliver treatment, as well as a highly trained staff to ensure the best planning and treatment.
How does it differ from traditional (photon) therapy?
Proton therapy is different from traditional X-ray or photon therapy because it aims high-energy protons very accurately at the area of concern. Once protons enter the body, they deposit their energy (dose) at a precise location and stop, allowing no dose of radiation to go farther into the body. With more common radiation treatments that use X-rays (also known as photons or gamma rays), radiation is aimed precisely at the tumor. However, some radiation continues through the body, radiating organs and tissues that may not require treatment. This dose is called the "exit dose" and is almost non-existent with proton therapy.
What are its advantages?
The biggest advantage of proton therapy for children is that it reduces the dose to the body outside of the tumor area. In addition, there tends to be less radiation deposited between the entry point on the surface of the patient's body to the target area, know as the "entrance dose." Proton therapy may allow more aggressive treatment of tumors near or within sensitive organs, such as the lungs. In children, there may be a reduction in side effects with proton therapy. There's convincing evidence that even low doses of traditional radiation can increase the risk of secondary tumors.
Why was it a good choice for Jake's rhabdomyosarcoma?
Jake (the patient featured in the profile above) had a relatively rare cancer of the soft tissue that originated in the skeletal muscle.