Imaging of gastrointestinal stromal tumors and assessment of benefit from systemic therapy.

While gastrointestinal stromal tumors have been increasingly recognized with the prolonged survival and highly effective new targeted treatments, the role of imaging has become important not only for diagnosing and staging the tumors, but also for monitoring the effects of treatment and surveillance. Computed tomography is the imaging modality of choice for these purposes. Fluorine-18 fluorodeoxyglucose positron emission tomography is primarily used in problem solving when there are inconsistencies between CT and clinical findings or inconclusive CT images. The roles of MRI and ultrasound are also described.