This prospective study evaluates the clinical utility of a novel real-time localization
system allowing for smaller volumes of normal tissue to be included in radiation field and
determines dosimetric parameters and adverse effect profiles of radiation therapy using this
technology. Subjects will have beacon transponders implanted into the prostate to more
precisely localize the position of the organ during radiation therapy. Hypothesis: 1.
Treatment with highly targeted radiation therapy can be delivered in a daily treatment time
consistent with routine clinical practice. 2. Highly targeted radiation therapy with reduced
PTV margin will result in a significant decrease in rectal and bladder volume treated.