Positron emission tomography for the diagnosis and management of patients with gastrointestinal malignancies.

F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) can play an important role in evaluating patients who have locally advanced diseases and in recurrence detection and restaging in patients who have gastrointestinal tract malignancies. Introduction of an integrated PET/CT system enabled the precise co-evaluation of function and morphology and improved the diagnostic ability of FDG-PET. Application of FDG-PET for treatment response evaluation and prognosis prediction is becoming important. Development of novel PET probes is expected to improve the characterization of individual cancer and to contribute to individualized patient management.