The purpose of this work is to provide background and current directions of image guidance for localized prostate cancer treatments. We will describe the external beam hypofractionation protocol for localized prostate cancer currently in progress at Stanford University and the biological bases for large fractions in an abbreviated treatment course for prostate cancer. The need for image guidance in external beam prostate cancer treatments will be discussed. Our experience with two imageguided implementations of hypofractionated radiotherapy for localized prostate cancer will be presented. These are the Cyberknife System (Accuray, Inc.) and the Trilogy System (Varian Medical Systems, Inc.).