Patterns and Prevalence of FDG Extravasation in PET/CT Scans

PET (Positron Emission Tomography) images are used to help make patient management decisions in staging and treatment assessment, often after a cancer diagnosis. Improper injections of PET tracers (dye) may occur approximately 15% of the time. This is known as extravasation or infiltration, and it compromises the doctor's ability to read the PET image. Often, the site where the tracer is injected into the vein (usually in the inside of the elbow) are not in the images taken, so reading physicians are unaware that an extravasation or infiltration has occurred. Technology exists to capture time activity curves (amount of tracer in a location over a period of time) during the PET tracer uptake period (usually once the tracer is injected, the tracer circulates for 60 minutes prior to images), which can enable physicians to accurately detect extravasations and infiltration. This information is currently unavailable to physicians reading routine PET/CT (computed tomography) scans. Time activity curves information gathered from these sensors during the circulation period appear to match the brief pictures taken approximately 70 minutes after the tracer injection. This study will determine if these time activity curves correspond to PET images of the injection site taken during the tracer uptake period. If time activity curves correspond to PET images, they can be used to determine if the tracer was properly injected. If there was an improper injection, clinicians can be alerted to this fact and interpret the image with this additional information.