Sam Beddar, PhD, is a tenured professor in the Division of Radiation Oncology, University of Texas (UT) MD Anderson Cancer Center, Houston, USA; professeur adjoint in the Département de Physique, Génie Physique et Optique, Université Laval, Québec City, Québec, Canada; and adjunct professor in the Department of Medical Physics, University of Wisconsin School of Medicine, Madison, Wisconsin, USA. He is also the chief of clinical research and service chief of gastrointestinal service in the Department of Radiation Physics at the UT MD Anderson Cancer Center. His research interests include scintillation dosimetry, intraoperative radiation therapy, four-dimensional computerized tomography, four-dimensional magnetic resonance imaging techniques for radiation therapy, and prompt gamma imaging for proton therapy. He has served as a mentor for many graduate students, postdoctoral research fellows, and clinical residents. Dr. Beddar has published more than 140 scientific papers and book chapters, and served as a reviewer for National Institutes of Health (NIH) study section review panels. Dr. Beddar has been principal investigator, co-investigator, and/or project leader on NIH R01, SBIR phase I, SBIR phase II, P01, R21, R43, R44, and T32 grants, and numerous industrial grants. He has served as an associate editor for Medical Physics, section editor for the Journal of Applied Clinical Medical Physics, and reviewer for numerous scientific journals, including the International Journal of Radiation Oncology, Biology, Physics, and Physics in Medicine and Biology. Luc Beaulieu, PhD, is a professor in the Department of Physics and director of the Graduate Medical Physics Program at Université Laval, Québec City, Québec, Canada (part of Canada’s top 10 research universities), as well as a medical physicist and head of the Medical Physics Research Group in the Department of Radiation Oncology, Centre Hospitalier Universitaire de Québec, Québec City, Canada. He is the recipient of numerous awards and has organized many international conferences. Dr. Beaulieu has been the author or coauthor of more than 185 articles published in refereed journals. He has served as president of the Canadian Organization of Medical Physicists and is an active member of the American Association of Physicists in Medicine, American Society for Therapeutic Radiology and Oncology, European Society for Radiotherapy and Oncology, and American Brachytherapy Society. Dr. Beaulieu’s research interests include image-guided brachytherapy, Monte Carlo dose calculation methods, and detector development.