Proton Therapy is a treatment of diseased tissue using a beam of protons to target the affected region. The advantage of protons is that they can be more precisely focused in a narrow radiation pattern. Because protons are charged particles, they are very effective at damaging the DNA of the tumor cells. Medical Physicists are at the forefront of refining this technology.rachytherapy refers to placing radiation sources adjacent to the cancerous tissue or inside a region that may contain residual cancer after surgery. This technique is used especially for breast and prostate cancers. Medical Physicist continue to research the most effective means to employ this procedure for various types of cancer.