Imaging is a critical component in the delivery of radiotherapy to patients with malignancy, and this book teaches the principles and practice of imaging specific to radiotherapy. Introductory chapters outline the basic principles of the available imaging modalities including x-rays, ultrasound, CT, MR, nuclear medicine, and PET. Site specific chapters then cover the main tumor sites, reviewing optimal imaging techniques for diagnosis, staging, radiotherapy planning, and follow-up for each site. Chapters are co-authored by oncologists and radiologists specializing in a specific area to provide an authoritative view on the role of imaging in the patient's journey and examples of relevant images are provided throughout. The important areas of radiation protection, exposure justification, and risks, are also comprehensively covered, exploring issues such as balancing radiation exposure with long-term risks of radiation effects, such as second cancer induction.