PROJECT SUMMARY/ABSTRACT (Radiosensitization Core) The Radiosensitization Core within this SPORE will provide specialized expertise, instrumentation and technical services to each of the Projects for their research activities related to evaluation of radiation sensitization of therapeutic agents. These services include irradiation of cultured cells and animal models, development of treatment plans for conformal irradiation of subcutaneous and orthotopic tumors, evaluation of therapeutic response using imaging with the goal of optimizing dose and schedule of the combination therapies in a rational and mechanism driven manner. The Core features three orthovoltage units, a SARRP (Small Animal Radiation Research Platform) which permits bioluminescence and CT-guided delivery of radiation to animals as well a laser microirradiation instrument to study DNA repair in single cells. Additionally, the Radiosensitization Core will be a central conduit for SPORE investigators to access research resources within the Rogel Cancer Center, including the Pharmacokinetics Shared Resource and the Preclinical Imaging and Computational Analysis Shared Resource. Dr. Balter, will oversee activities related to image-guided radiation therapy and conformal treatment planning. Dr. Rehemtulla, will guide studies on mouse models of cancer and imaging to provide quantitative and mechanistic insights for each of the project-specific therapeutic paradigms. Dr. Leopold will oversee research related to preclinical optimization of dosing and schedule for test agents in a manner that informs design of the planned clinical trials in each project. The Radiosensitization Core will also work seamlessly with the other Cores within the SPORE, the Biostatistics and Computational Biology Core and the Translational Pathology Core, to ensure that the planning and execution of pre-clinical studies is conducted with scientific rigor and consistent with the goals of each of the projects. The integration of the Radiosensitization core with each of the research Projects and the Cores is critical and will provide SPORE investigators the ability to conduct studies that positively impact the management of patients undergoing radiation therapy.