Whole-Body Biodistribution, Dosimetry, and Metabolite Correction of [11C]Palmitate: A PET Tracer for Imaging of Fatty Acid Metabolism:

Introduction:Despite the decades long use of [11C]palmitate positron emission tomography (PET)/computed tomography in basic metabolism studies, only personal communications regarding dosimetry and biodistribution data have been published.Methods:Dosimetry and biodistribution studies were performed in 2 pigs and 2 healthy volunteers by whole-body [11C]palmitate PET scans. Metabolite studies were performed in 40 participants (healthy and with type 2 diabetes) under basal and hyperinsulinemic conditions. Metabolites were estimated using 2 approaches and subsequently compared: Indirect [11C]CO2 release and parent [11C]palmitate measured by a solid-phase extraction (SPE) method. Finally, myocardial fatty acid uptake was calculated in a patient cohort using input functions derived from individual metabolite correction compared with population-based metabolite correction.Results:In humans, mean effective dose was 3.23 (0.02) µSv/MBq, with the liver and myocardium receiving the highest absorbed doses. Metabolite ...