Moreton Lecture: Imaging in the Age of Precision Medicine.

The term "precision medicine" (also known as "personalized medicine") is broadly defined as the tailoring of medical treatment to the individual characteristics of each patient. This process entails classifying patients into subpopulations that differ in their susceptibility to a particular disease, in the biology and/or prognosis of those diseases they may develop, or in their response to a specific treatment. Subpopulations are defined through systematic analysis and classification of patients' genotypic and phenotypic characteristics. Image findings are surrogates for phenotype manifestation of disease, and radiology reports are written descriptions of imaging phenotypes. Imaging phenotypes are often presented as classification, grading, or scoring systems that help assign patients to subpopulations for selecting treatment or assessing prognosis. The "spot sign score" that reflects the severity of bleeding in intracerebral hemorrhage is an example that has been used as an inclusion criterion in clinical trials. The term "radiogenomics" is used to describe the study of linkage between a patient's genotype and imaging phenotype. When a patient's genotype is known, it often suggests a surveillance role for imaging to determine clinical occurrence, location, extent, and severity of the associated disease; for example, use of breast imaging for enhanced surveillance in women known to harbor the BRCA1 and BRCA2 genes. Imaging is poised to play major roles in the age of precision medicine. The imaging community needs to learn new terminology and think in terms of how imaging phenotypes and imaging surveillance of patients with known genetic mutations can contribute to the concept.