My research group is focused on applications of emerging functional and molecular imaging techniques in radiation therapy of cancer. In order to integrate these novel imaging procedures with state-of-the-art radiation therapy, a number of issues must be addressed. First, what are the molecular targets that hold the most promise for targeting and monitoring response to radiation therapy, and how can they best be visualized in vivo? Second, what are the limitations of novel imaging techniques that may bear on their application in radiation oncology? Third, how can one display, analyze, and segment multiple three-dimensional datasets to generate target volumes for radiotherapy? And finally, how will the information contained in imaging results of different modalities be integrated into the selection of a treatment course for a patient and subsequently, where appropriate, the specification of an optimized radiation target?