title: The added value of68Ga-DOTA-TATE-PET to contrast-enhanced CT for primary site detection in CUP of neuroendocrine origin.
abstract: OBJECTIVE
  To quantify the additional value of68Ga-DOTA-TATE PET/CT in comparison with contrast-enhanced CT alone for primary tumour detection in neuroendocrine cancer of unknown primary (CUP-NET).
  
  
  METHODS
  In total, 38 consecutive patients (27 men, 11 women; mean age 62 years) with histologically proven CUP-NET who underwent a contrast-enhanced68Ga-DOTA-TATE PET/CT scan for primary tumour detection and staging between 2010 and 2014 were included in this IRB-approved retrospective study. Two blinded readers independently analysed the contrast-enhanced CT and68Ga-DOTA-TATE PET datasets separately and noted from which modality they suspected a primary tumour. Consensus was reached if the results were divergent. Postoperative histopathology (24 patients) and follow-up68Ga-DOTA-TATE PET/CT imaging (14 patients) served as the reference standards and statistical measures of diagnostic accuracy were calculated accordingly.
  
  
  RESULTS
  The majority of confirmed primary tumours were located in the abdomen (ileum in 19 patients, pancreas in 12, lung in 2, small pelvis in 1). High interobserver agreement was noted regarding the suspected primary tumour site (Cohen's k 0.90, p < 0.001).68Ga-DOTA-TATE PET demonstrated a significantly higher sensitivity (94 % vs. 63 %, p = 0.005) and a significantly higher accuracy (87 % vs. 68 %, p = 0.003) than contrast-enhanced CT.
  
  
  CONCLUSIONS
  Ga-DOTA-TATE PET/CT compared with contrast-enhanced CT alone provides an improvement in sensitivity of 50 % and an improvement in accuracy of 30 % in primary tumour detection in CUP-NET.
  
  
  CONCLUSIONS
  •68Ga-DOTA-TATE PET augments the sensitivity of contrast-enhanced CT by 50 % •68Ga-DOTA-TATE PET augments the accuracy of contrast-enhanced CT by 30 % • Somatostatin receptor-targeted hybrid imaging optimizes primary tumour detection in CUP-NET.
authors.affiliation: Institut für Klinische Radiologie, Klinikum der Universität München, Marchioninistraße 15, 81377, München, Germany. philipp.kazmierczak@med.lmu.de.|Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, München, Germany. philipp.kazmierczak@med.lmu.de.
authors.forename: Philipp M
authors.initials: PM
authors.lastname: Kazmierczak
authors.affiliation: Department of Nuclear Medicine, Ludwig-Maximilians-University Hospital Munich, München, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Rominger
authors.affiliation: Department of Nuclear Medicine, Ludwig-Maximilians-University Hospital Munich, München, Germany.
authors.forename: Vera
authors.initials: V
authors.lastname: Wenter
authors.affiliation: Department of Internal Medicine II, Ludwig-Maximilians-University Hospital Munich, München, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Spitzweg
authors.affiliation: Department of Internal Medicine II, Ludwig-Maximilians-University Hospital Munich, München, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Auernhammer
authors.affiliation: Department of General, Visceral, Transplantation, Vascular and Thoracic Surgery, Ludwig-Maximilians-University Hospital Munich, München, Germany.
authors.forename: Martin K
authors.initials: MK
authors.lastname: Angele
authors.affiliation: Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, München, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Rist
authors.affiliation: Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, München, Germany.
authors.forename: Clemens C
authors.initials: CC
authors.lastname: Cyran
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009382:Neoplasms, Unknown Primary / Q000000981:diagnostic imaging*; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging*; D015588:Observer Variation; D009942:Organometallic Compounds; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods; D049268:Positron-Emission Tomography / Q000379:methods; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D009942:Organometallic Compounds; D019275:Radiopharmaceuticals; C513399:gallium Ga 68 dotatate
keywords: 68Ga-DOTATATE; Multislice computed tomography; Neuroendocrine tumours; Positron emission tomography; Unknown primary