LUNG-CANCER - REPRODUCIBILITY OF QUANTITATIVE MEASUREMENTS FOR EVALUATING 2-[F-18]-FLUORO-2-DEOXY-D-GLUCOSE UPTAKE AT PET

PURPOSE: To study the precision of repeated 2-[fluorine-18]-fluoro-2-d eoxy-D-glucose (FDG) uptake measurements al positron emission tomograp hy (PET) in patients with primary lung cancer. MATERIALS AND METHODS: Ten patients with untreated lung cancer underwent two dynamic FDG PET examinations after a 4-hour fast within 1 week. Kinetic modeling of tu mor FDG uptake was performed on the basis of a three-compartment model . The tumor concentration of F-18 (standardized uptake value calculate d on the basis of predicted lean body mass [SUV-lean]) was also measur ed 50-60 minutes after injection of a tracer. Blood glucose, insulin, and free fatty acid levels were monitored. RESULTS: SUV-lean and the F DG influx constant K-i were measured with a mean +/- standard deviatio n difference of 10% +/- 7 and 10% +/- 8, respectively, over repeated P ET scans. The mean difference was reduced to 6% +/- 6 and 6% +/- 5 by multiplying SUV-lean and K-i by plasma glucose concentration. CONCLUSI ON: SUV-lean and graphical K-i can be measured reproducibly, supportin g their use in quantitative FDG PET algorithms.