title: Impact of Multiphase 68Ga-DOTATOC-PET/CT on therapy management in patients with neuroendocrine tumors.
abstract: OBJECTIVE
  Retrospective evaluation of the impact of integrated positron emission tomography/computed tomography (PET/CT) using (68)Ga-DOTA(0)-Phe(1)-Tyr(3)-octreotide ((68)Ga-DOTATOC) on the therapeutic management of patients with neuroendocrine tumors (NET).
  
  
  METHODS
  The (68)Ga-DOTATOC-PET/CT data of 66 patients (31 male, 35 female; age: 29-79, mean age: 56 years) with known or suspected NET were included. Imaging data (PET and triple-phase contrast-enhanced CT) were evaluated in consensus by two readers for the visualization of NET manifestations. Combined PET/CT, clinical and imaging follow-up as well as histopathology (if available) served as the reference standard. In order to assess the impact of the respective submodalities on the therapeutic strategy chosen, the results were compared to the treatment decision made by the interdisciplinary NET tumor board of our institution.
  
  
  RESULTS
  Two of the initial 66 patients included did not suffer from NET according to further immunohistopathological examination. In 50 of the remaining 64 (78%) NET patients, a total of 181 NET manifestations were detected by PET/CT. 59/181 (32.6%) were detected by one submodality only (CT 17.1%, PET 15.5%, p for comparison of both = 0.459). Combined PET/CT reading had an impact on the therapeutic management in 24 of 64 (38%) NET patients: primary resection (n = 5), curative lymph node resection (n = 1), initiation/switch of chemotherapy (CTx) due to progressive disease (n = 10), no surgery due to systemic disease (n = 2), radiopeptide receptor therapy instead of CTx (n = 1), additional bisphosphonate therapy (n = 4), and hepatic brachytherapy (n = 1). In 12 of 24 (50%) of these patients, relevant findings were detected by a single submodality only: CT (n = 5), PET (n = 7); p for comparison = 0.774).
  
  
  CONCLUSIONS
  (68)Ga-DOTATOC-PET/CT influences therapeutic management in about one third of patients examined. CT and PET are comparably sensitive, deliver complementary information and equally contribute to therapeutic decision-making. Thus, despite the merits of the PET modality, the CT component must not be neglected and an optimized multiphase CT protocol is recommended.
authors.affiliation: Klinik für Radiologie und Nuklearmedizin, Universitätsklinikum Magdeburg AöR, Magdeburg, Germany. juri.ruf @ med.ovgu.de
authors.forename: Juri
authors.initials: J
authors.lastname: Ruf
authors.forename: Friederike
authors.initials: F
authors.lastname: Heuck
authors.forename: Jan
authors.initials: J
authors.lastname: Schiefer
authors.forename: Timm
authors.initials: T
authors.lastname: Denecke
authors.forename: Florian
authors.initials: F
authors.lastname: Elgeti
authors.forename: Andreas
authors.initials: A
authors.lastname: Pascher
authors.forename: Marianne
authors.initials: M
authors.lastname: Pavel
authors.forename: Lars
authors.initials: L
authors.lastname: Stelter
authors.forename: Siegfried
authors.initials: S
authors.lastname: Kropf
authors.forename: Bertram
authors.initials: B
authors.lastname: Wiedenmann
authors.forename: Holger
authors.initials: H
authors.lastname: Amthauer
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000473:pathology* / Q000628:therapy*; D015282:Octreotide / Q000031:analogs & derivatives*; D009942:Organometallic Compounds; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: C499142:Ga(III)-DOTATOC; D009942:Organometallic Compounds; D019275:Radiopharmaceuticals; D015282:Octreotide