External Beam Radiation Therapy is a type of treatment that can be used for prostate cancer. This type of treatment works by targeting the prostate gland with beams of radiation. After your prostate has been mapped and your body has been set into place by a fitted mold, shaped beams of radiation are directed at the prostate from several directions which kills the cancer cells. There are two types of radiation that your doctor may use. These include either three dimensional conformal radiotherapy (3DCRT) or intensity-modulated radiotherapy (IMRT).