title: [(68)Ga]PSMA-HBED uptake mimicking lymph node metastasis in coeliac ganglia: an important pitfall in clinical practice.
abstract: OBJECTIVE
  To determine the frequency of seemingly pathological retroperitoneal uptake in the location of the coeliac ganglia in patients undergoing [(68)Ga]PSMA-HBED PET/CT.
  
  
  METHODS
  The study included 85 men with prostate cancer referred for [(68)Ga]PSMA-HBED PET/CT. The PET/CT scans were evaluated for the local finding in the prostate and the presence of lymph node metastases, distant metastases and coeliac ganglia. The corresponding standardized uptake values (SUV) were determined. SUVmax to background uptake (gluteal muscle SUVmean) ratios were calculated for the ganglia and lymph node metastases. Immunohistochemistry was performed on the ganglia.
  
  
  RESULTS
  In 76 of the 85 patients (89.4%) at least one ganglion with tracer uptake was found. For the ganglia, SUVmax and SUVmax to background SUVmean ratios were 2.97 ± 0.88 and 7.98 ± 2.84 (range 1.57-6.38 and 2.83-30.6), respectively, and 82.8% of all ganglia showed an uptake ratio of >5.0. For lymph node metastases, SUVmax and SUVmax to background SUVmean ratios were 8.5 ± 7.0 and 23.31 ± 22.23 (range 2.06-35.9 and 5.25-115.8), respectively. In 35 patients (41.2%), no lymph node metastases were found but tracer uptake was seen in the ganglia. Immunohistochemistry confirmed strong PSMA expression in the ganglia.
  
  
  CONCLUSIONS
  Coeliac ganglia show a relevant [(68)Ga]PSMA-HBED uptake in most patients and may mimic lymph node metastases.
authors.affiliation: Department of Nuclear Medicine, RWTH University Hospital Aachen, Pauwelsstraße 30, 52074, Aachen, Germany, tkrohn@ukaachen.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Krohn
authors.forename: Frederik A
authors.initials: FA
authors.lastname: Verburg
authors.forename: Thomas
authors.initials: T
authors.lastname: Pufe
authors.forename: Winfried
authors.initials: W
authors.lastname: Neuhuber
authors.forename: Andreas
authors.initials: A
authors.lastname: Vogg
authors.forename: Alexander
authors.initials: A
authors.lastname: Heinzel
authors.forename: Felix M
authors.initials: FM
authors.lastname: Mottaghy
authors.forename: Florian F
authors.initials: FF
authors.lastname: Behrendt
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002447:Celiac Plexus / Q000000981:diagnostic imaging*; D004492:Edetic Acid / Q000031:analogs & derivatives*; D005189:False Positive Reactions; D005709:Gallium Isotopes; D005710:Gallium Radioisotopes; D006801:Humans; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009842:Oligopeptides; D049268:Positron-Emission Tomography; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging*; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed
chemical_list: D005709:Gallium Isotopes; D005710:Gallium Radioisotopes; D009842:Oligopeptides; D019275:Radiopharmaceuticals; C000718244:gallium 68 PSMA-11; D004492:Edetic Acid