title: Normal uptake of 68Ga-DOTA-TOC by the pancreas uncinate process mimicking malignancy at somatostatin receptor PET.
abstract: OBJECTIVE
  To characterize a commonly occurring increased uptake by the uncinate process of the pancreas at PET/CT using 68Ga-DOTA-d-Phe1-Tyr3-octreotide (68Ga-DOTA-TOC). This tracer has replaced In pentetreotide (OctreoScan®) for somatostatin receptor scintigraphy at our laboratory.
  
  
  METHODS
  Fifty of our first 74 PET/CT examinations with 68Ga-DOTA-TOC could be evaluated in retrospect. None of these patients had surgery or showed any pathology in the pancreas head at the concomitant CT.
  
  
  RESULTS
  Thirty-five of the 50 examinations (70%) showed an uptake by the uncinate process sufficiently intense to be interpreted as pathologic and simulating a tumor. Mean SUVmax was 9.2. Mean SUVmean using an isoactivity cut-off of >75% and >50% was 7.8 and 6.0, respectively. Volume calculations of the uncinate process activity using these definitions gave 0.9 mL and 4.2 mL, respectively.
  
  
  CONCLUSIONS
  There is a frequent physiological uptake of 68Ga-DOTA-TOC by the pancreas uncinate process. This may be caused by an accumulation of pancreatic polypeptide-containing cells expressing somatostatin receptors. If there is a normal finding at concomitant diagnostic CT, this uptake should be regarded as physiological.
authors.affiliation: Department of Radiology, Karolinska University Hospital Solna, Stockholm, Sweden. hans.jacobsson@karolinska.se
authors.forename: Hans
authors.initials: H
authors.lastname: Jacobsson
authors.forename: Patricia
authors.initials: P
authors.lastname: Larsson
authors.forename: Cathrine
authors.initials: C
authors.lastname: Jonsson
authors.forename: Emma
authors.initials: E
authors.lastname: Jussing
authors.forename: Per
authors.initials: P
authors.lastname: Grybäck
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001692:Biological Transport; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D015282:Octreotide / Q000031:analogs & derivatives* / Q000378:metabolism; D009942:Organometallic Compounds / Q000378:metabolism*; D010179:Pancreas / Q000002:abnormalities* / Q000000981:diagnostic imaging* / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism*; D049268:Positron-Emission Tomography; D017481:Receptors, Somatostatin / Q000378:metabolism*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: C499142:Ga(III)-DOTATOC; D009942:Organometallic Compounds; D017481:Receptors, Somatostatin; D015282:Octreotide