This book is a concise and well-illustrated review of the physics and biology of radiation therapy intended for radiation therapists, dosimetrists, radiation oncology residents, and physicists. It presents topics that are included on the radiation therapy physics and biology board examinations and is designed with the intent of presenting information in an easily digestible format with maximum retention in mind. The inclusion of mnemonics, rules of thumb, and reader-friendly illustrations throughout the book help to make difficult concepts easier to grasp. This new edition is updated throughout with the latest information and applications of radiation oncology physics and biology and includes four new chapters. New topics include: MRI linac, proton beam radiotherapy, chemomodulation and immunomodulation of radiation in vitro and in vivo, and stochastic and deterministic late effects. Basic Radiotherapy Physics and Biology is a valuable reference for radiation oncologists, medical professionals in the field, residents, and all students interested in radiation oncology.