We report on experience and insights gained from prototyping, for clinical radiation oncologists, a new access tool for the University of Washington Digital Anatomist information resources. This access tool is designed to integrate with a radiation therapy planning (RTP) system in use in a clinical setting. We hypothesize that the needs of practitioners in a clinical setting are different from the needs of students, the original targeted users of the Digital Anatomist system, but that a common knowledge resource can serve both. Our prototype was designed to help define those differences and study the feasibility of a full anatomic reference system that will support both clinical radiation therapy and all the existing educational applications.