The current practice of radiation oncology now requires a strong relationship with all radiology subspecialists and is embedded with a variety of imaging modalities and formats for both treatment planning and treatment execution. Unlike technology in the past, modern treatment technology delivery systems include kilovoltage imaging and cone beam computed tomography–guided treatment systems for daily patient treatment reproducibility. Today's radiation planning tools include 4-dimensional motion management and fusion software that can routinely blend anatomic and metabolic imaging for target volume definition. Imaging tools are used daily for each patient by all members of a modern radiation oncology department. As imaging tools improve and can be successfully registered with radiation planning imaging, targets will be further refined and patient-specific treatment planning optimized with confidence that the target is reproduced correctly every treatment day. Imaging has become symbiotic with all elements of daily practice, and application of emerging imaging tools will be an essential component of modern radiation oncology clinical translational research for the next generation of clinical trial investigators.