This issue of Hematology/Oncology Clinics, Guest Edited by Drs. Ravi A. Chandra, Lisa A. Kachnic, Charles R. Thomas, Jr., is part one of a two-part issue focused on Contemporary Topics in Radiation Medicine. Topics include, but are not limited to, Basic Medical Physics, Basic Radiobiology, Modern Radiation Treatment Planning & Delivery, Advanced Imaging Techniques in Diagnosis and Tx, Particle Therapy/Protons, SRS/SBRT, Modern Brachytherapy, Immunotherapy/Abscopal, Nanotechnology, Bioinformatics & Artificial Intelligence, Quality-of-life & Outcomes, Normal Tissue Issues and Toxicity, Radiation Modifiers, and Health Economics/Disparities.