This study will seek to establish the clinical feasibility of a novel real-time localization and tracking system for use of reduced PTV margins during intensity modulated radiation therapy (IMRT), which will allow treatment of smaller volumes of normal tissue during radiation therapy. Such a reduction in the PTV margins and the exposure of healthy tissue during treatment may allow for several future improvements in prostate radiotherapy including:
* decreased acute and chronic adverse effects with similar local tumor control
* dose escalation to achieve higher cure rates with similar adverse effects to standard dose treatment
* hypofractionation to shorten the time of, and lower the expense of, treatment without increased adverse effects.
