title: Functional imaging of neuroendocrine tumors with combined PET/CT using 68Ga-DOTATATE (DOTA-DPhe1,Tyr3-octreotate) and 18F-FDG.
abstract: BACKGROUND
  The aim was to assess the relevant distribution of the novel PET tracer (68)Ga-DOTATATE in neuroendocrine tumors (NETs) with combined positron emission tomography / computed tomography (PET/CT) and compare its performance with that of (18)F-FDG PET/CT.
  
  
  METHODS
  The imaging findings with (68)Ga-DOTATATE and (18)F-FDG on 38 consecutive patients with a diagnosis of primary or recurrent NET were compared and correlated with tumor grade on histology based on ki67 and mitotic index.
  
  
  RESULTS
  The sensitivity of (68)Ga-DOTATATE PET/CT was 82% (31 of 38) and that of (18)F-FDG PET/CT was 66% (25 of 38). The sensitivity of combined (68)Ga-DOTATATE and (18)F-FDG PET/CT was 92% (35 of 38). There was greater uptake of (68)Ga-DOTATATE than (18)F-FDG in low-grade NET (median SUV 29 vs 2.9, P < .001). In high-grade NET there was higher uptake of (18)F-FDG over (68)Ga-DOTATATE (median SUV 11.7 vs 4.4, P = .03). There was a significant correlation with predominant tumor uptake of (68)Ga-DOTATATE or (18)F-FDG and tumor grade on histology (P < .0001).
  
  
  CONCLUSIONS
  (68)Ga-DOTATATE PET/CT is a useful novel imaging modality for NETs and is superior to (18)F-FDG for imaging well-differentiated NET. Functional imaging with both (68)Ga-DOTATATE and (18)F-FDG has potential for a more comprehensive tumor assessment in intermediate- and high-grade tumors.
authors.affiliation: Institute of Nuclear Medicine, University College Hospital, London, UK.
authors.forename: Irfan
authors.initials: I
authors.lastname: Kayani
authors.forename: Jamshed B
authors.initials: JB
authors.lastname: Bomanji
authors.forename: Ashley
authors.initials: A
authors.lastname: Groves
authors.forename: Gerard
authors.initials: G
authors.lastname: Conway
authors.forename: Sveto
authors.initials: S
authors.lastname: Gacinovic
authors.forename: Thida
authors.initials: T
authors.lastname: Win
authors.forename: John
authors.initials: J
authors.lastname: Dickson
authors.forename: Martyn
authors.initials: M
authors.lastname: Caplin
authors.forename: Peter Joseph
authors.initials: PJ
authors.lastname: Ell
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18; D005708:Gallium; D006801:Humans; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging*; D009942:Organometallic Compounds; D049268:Positron-Emission Tomography; D011379:Prognosis; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D015996:Survival Rate; D014057:Tomography, X-Ray Computed
chemical_list: D009942:Organometallic Compounds; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; C513399:gallium Ga 68 dotatate; D005708:Gallium