The purpose of this study was to evaluate [1-11C]-acetate as a tracer for functional imaging of the pancreas and related diseases using position emission tomography (PET).
Methods: Thirty-three patients underwent 30 min of dynamic attenuation-corrected PET after intravenous administration of 740 MBq (20 mCi) of [1-11C]-acetate.
Results: The normal pancreas demonstrates prompt uptake of [1-11C]-acetate and is visualized as early as 2 min post-injection, with maximal activity achieved by 5 min. Subsequent clearance of tracer from the pancreas is slow relative to adjacent organs and background, such that by 10 min post-injection the pancreas is the most prominent organ in the imaging field of view. Pancreatic uptake of [1-11C]-acetate was unaffected by pancreatic endocrine insufficiency, but is absent in chronic pancreatitis complicated by exocrine insufficiency. Moderately reduced [1-11C]-acetate uptake was observed in acute uncomplicated pencreatitis. The level of tracer accumulation was substantially reduced in phlegmatous masses complicating pancreatitis and in chronic mass forming pancreatitis. Adenocarcinoma of the pancreas likewise demonstrated no significant uptake of [1-11C]-acetate.
Conclusions: Accumulation of [1-11C]-acetate by the pancreas allows rapid metabolic imaging using PET, and may be a useful metabolic probe for the study of pancreatic physiology and disease.