conformal proton beam therapy
a technique for giving radiation therapy that uses proton beams rather than standard radiation. (Protons are parts of atoms.) Unlike standard radiation beams, which release energy both before and after hitting the target, proton beams cause less damage to tissues they pass through, and then release their energy after traveling a certain distance. Proton beam therapy has not been directly compared to standard radiation methods, but the hope is that it may be able to deliver more radiation to the cancer with less damage to nearby normal tissues. It is still fairly new and is offered in only a small number of treatment centers. See also conformal radiation therapy, external beam radiation therapy, ionizing radiation.