Project Summary: This training program prepares eight predoctoral graduate students and three postdoctoral researchers for careers in the application of physics to the medical diagnosis and treatment of cancer. Available research specializations encompass broad areas of physics as applied to disease diagnosis, patient-specific treatment and assessment of treatment efficacy, and basic physics research applied to cancer. The 34 mentors and 17 other Participating Faculty in the Departments of Medical Physics, Radiology, Human Oncology (Radiation Oncology), Engineering Physics, and Biomedical Engineering maintain a broad spectrum of research collaborations with other clinical and basic science researchers. Translational, team-driven research includes traditional x-ray, CT, MRI, ultrasound, and PET imaging with the Department of Radiology, and radiation physics, radiation biology, and radiation therapy with the Departments of Physics, Nuclear Engineering, and Human Oncology. Trainees are intimate participants in these research programs as collaborators, publishing joint research articles, and performing as investigators in extramurally funded grants and contracts. Extensive faculty contact provides leadership and supervision. Beyond research activities, predoctoral trainees as graduate students in Medical Physics take at least twenty-six credits supportive of medical physics training and oriented towards their research specialization. Nominees for predoctoral positions in this training program typically have passed their preliminary examination of a proposed PhD research plan related to cancer. This significantly increases the likelihood of their remaining in cancer-related research and shortens their typical time in the NRSA position to about two years. Postdoctoral trainees are encouraged to broaden and deepen their academic training by auditing appropriate courses, and their appointments are typically 2-3 years. Both predoctoral and postdoctoral trainees must take or audit additional research ethics courses, cancer-specific courses, must attend relevant grand round presentations, and must participate in intensive workshops on manuscript writing and grant writing. Trainees give seminars, attend colloquia, present research results at local, national, and international meetings, and co-author articles and reports. An annual Training Grant Symposium provides additional opportunity for trainees to present research results to the Medical Physics and collaborating faculty. In this way trainees in this program are well prepared to assume leadership positions as researchers and academicians in the application of physics to cancer prevention, diagnosis, and treatment.