title: Prospective Study of 68Ga-DOTATATE Positron Emission Tomography/Computed Tomography for Detecting Gastro-Entero-Pancreatic Neuroendocrine Tumors and Unknown Primary Sites.
abstract: OBJECTIVE
  Gastro-entero-pancreatic neuroendocrine tumors (GEPNETs) are increasing in incidence, and accurate staging is important for selecting the appropriate treatment. (68)Ga-DOTATATE imaging is a promising approach for detecting GEPNETs and could help in selecting optimal therapeutic strategies. The aim of this study was to prospectively determine the clinical utility of (68)Ga-DOTATATE positron emission tomography (PET)/computed tomography (CT) in detecting unknown primary and metastatic GEPNETs.
  
  
  METHODS
  One hundred thirty-one patients were enrolled in a prospective study of patients undergoing (68)Ga-DOTATATE PET/CT, (111)In-pentetreotide single-photon emission computed tomography (SPECT)/CT and multiphasic CT scan, and/or magnetic resonance imaging in a blinded fashion with comprehensive biochemical testing. The primary outcome measure was the detection of lesions by each imaging study.
  
  
  RESULTS
  (68)Ga-DOTATATE PET/CT imaging detected 95.1% of lesions (95% CI, 92.4% to 96.8%) with an average maximum standardized uptake value of 65.4 ± 47 (range, 6.9 to 244), anatomic imaging detected 45.3% of lesions (95% CI, 37.9% to 52.9%), and (111)In-pentetreotide SPECT/CT detected 30.9% of lesions (95% CI, 25.0% to 37.5%), with a significant difference between imaging modalities (P < .001). In four of 14 patients (28.6%), (68)Ga-DOTATATE PET/CT found a previously unknown primary tumor, and detected primary GEPNET, lymph node, and distant metastases correctly in 72 of 113 lesions (63.7%) when compared with histopathology, with 22.1% and 38.9% detected by using (111)In-pentetreotide SPECT/CT and anatomic imaging, respectively. On the basis of findings with (68)Ga-DOTATATE PET/CT, 43 of 131 patients (32.8%) had a change in management recommendation. In patients with carcinoid symptoms but negative biochemical testing, (68)Ga-DOTATATE PET/CT detected lesions in 65.2% of patients, 40% of which were detected neither by anatomic imaging nor by (111)In-pentetreotide SPECT/CT.
  
  
  CONCLUSIONS
  (68)Ga-DOTATATE PET/CT imaging provides important information for accurate staging of GEPNETs and selection of appropriate treatment interventions even in the absence of biochemical evidence of disease in symptomatic patients.
authors.affiliation: All authors: National Institutes of Health, Bethesda, MD.
authors.forename: Samira M
authors.initials: SM
authors.lastname: Sadowski
authors.affiliation: All authors: National Institutes of Health, Bethesda, MD.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Neychev
authors.affiliation: All authors: National Institutes of Health, Bethesda, MD.
authors.forename: Corina
authors.initials: C
authors.lastname: Millo
authors.affiliation: All authors: National Institutes of Health, Bethesda, MD.
authors.forename: Joanna
authors.initials: J
authors.lastname: Shih
authors.affiliation: All authors: National Institutes of Health, Bethesda, MD.
authors.forename: Naris
authors.initials: N
authors.lastname: Nilubol
authors.affiliation: All authors: National Institutes of Health, Bethesda, MD.
authors.forename: Peter
authors.initials: P
authors.lastname: Herscovitch
authors.affiliation: All authors: National Institutes of Health, Bethesda, MD.
authors.forename: Karel
authors.initials: K
authors.lastname: Pacak
authors.affiliation: All authors: National Institutes of Health, Bethesda, MD.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Marx
authors.affiliation: All authors: National Institutes of Health, Bethesda, MD. electron.kebebew@nih.gov.
authors.forename: Electron
authors.initials: E
authors.lastname: Kebebew
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D053379:Chromogranin A / Q000097:blood; D005260:Female; D006801:Humans; D006897:Hydroxyindoleacetic Acid / Q000652:urine; D007414:Intestinal Neoplasms / Q000175:diagnosis* / Q000473:pathology; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000556:secondary; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009382:Neoplasms, Unknown Primary / Q000175:diagnosis* / Q000473:pathology; D018358:Neuroendocrine Tumors / Q000175:diagnosis* / Q000556:secondary*; D009942:Organometallic Compounds; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D010191:Pancreatic Polypeptide / Q000097:blood; D010751:Phosphopyruvate Hydratase / Q000097:blood; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D013004:Somatostatin / Q000031:analogs & derivatives; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000473:pathology; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed; D014660:Vasoactive Intestinal Peptide / Q000097:blood; D055815:Young Adult
chemical_list: D053379:Chromogranin A; D009942:Organometallic Compounds; D014660:Vasoactive Intestinal Peptide; D013004:Somatostatin; D006897:Hydroxyindoleacetic Acid; D010191:Pancreatic Polypeptide; C513399:gallium Ga 68 dotatate; D010751:Phosphopyruvate Hydratase; C081788:pentetreotide