title: Significance of a Single-Time-Point Somatostatin Receptor SPECT/Multiphase CT Protocol in the Diagnostic Work-up of Gastroenteropancreatic Neuroendocrine Neoplasms.
abstract: This prospective study compared a 1-d SPECT/CT protocol with the commonly used 3-d protocol for somatostatin receptor scintigraphy in patients with gastroenteropancreatic neuroendocrine neoplasms. Additionally, the influence of SPECT/CT on patient management was evaluated.
  
  
  METHODS
  From October 2011 to October 2012, all gastroenteropancreatic neuroendocrine neoplasm patients undergoing restaging with somatostatin receptor scintigraphy on a modern SPECT/CT device were enrolled in this study. The protocol consisted of planar imaging at 4, 24, and 48 h; low-dose SPECT/CT at 24 and 48 h; diagnostic CT at 24 h using a triple-phase delay after administration of contrast; and diagnostic SPECT/CT at 24 h. All components of the imaging data were reassessed by 3 masked interpreters. The results were compared with a reference standard based on all clinical, imaging, and histopathology follow-up data available (follow-up range, 24-36 mo; mean, 29.9 mo). The reference standard was defined by a study-specific interdisciplinary tumor board that also reassessed treatment decisions.
  
  
  RESULTS
  Thirty-one patients were eligible for analysis (18 men and 13 women; mean age, 60.4 y). Ten had no imaging signs of disease and remained disease-free during follow-up. Twenty-one had persistent or recurrent disease (82 lesions: 24 in the liver, 21 in the lymph nodes, 16 in bone, 12 in the pancreas, and 9 in other locations). The respective lesion detection rates for interpreters 1, 2, and 3 were 51.9%, 49.4%, and 71.6% for low-dose SPECT/CT at 24 h; 51.9%, 55.6%, and 67.9% for low-dose SPECT/CT at 48 h; 63.0%, 70.4%, and 85.2% for diagnostic CT; and 77.8%, 84.0%, and 88.9% for diagnostic SPECT/CT. Interobserver agreement was moderate for diagnostic SPECT/CT (κ = 0.44), diagnostic CT (κ = 0.43), low-dose SPECT/CT at 48 h (κ = 0.61), and low-dose SPECT/CT at 24 h (κ = 0.55). For planar imaging, interobserver agreement was fair after 48 h (κ = 0.36) and 24 h (κ = 0.38) and moderate after 4 h (κ = 0.42). Every lesion detectable on planar imaging or low-dose SPECT/CT was also detectable on diagnostic SPECT/CT. The CT and SPECT components of diagnostic SPECT/CT strongly complemented each other, as 34 of 82 lesions (41.4%) were detected on only the CT component or only the SPECT component. Therapeutic management was influenced by the diagnostic SPECT/CT interpretation in 8 of 31 patients (25.8%).
  
  
  CONCLUSIONS
  The highest detection rates were achieved by diagnostic SPECT/CT. Thus, a more patient-friendly 1-d protocol is feasible. Furthermore, multiphase SPECT/CT affected management in about a quarter of patients.
authors.affiliation: Klinik für Radiologie und Nuklearmedizin, Universitätsklinikum Magdeburg A.ö.R., Magdeburg, Germany Klinik für Nuklearmedizin, Universitätsklinikum Freiburg, Freiburg, Germany.
authors.forename: Juri
authors.initials: J
authors.lastname: Ruf
authors.affiliation: Klinik für Radiologie und Nuklearmedizin, Universitätsklinikum Magdeburg A.ö.R., Magdeburg, Germany.
authors.forename: Friederike
authors.initials: F
authors.lastname: von Wedel
authors.affiliation: Klinik für Radiologie und Nuklearmedizin, Universitätsklinikum Magdeburg A.ö.R., Magdeburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Furth
authors.affiliation: Klinik für Strahlenheilkunde, Campus Virchow-Klinikum, Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Timm
authors.initials: T
authors.lastname: Denecke
authors.affiliation: Klinik für Strahlenheilkunde, Campus Virchow-Klinikum, Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Lars
authors.initials: L
authors.lastname: Stelter
authors.affiliation: Klinik für Radiologie und Nuklearmedizin, Universitätsklinikum Magdeburg A.ö.R., Magdeburg, Germany.
authors.forename: Ingo G
authors.initials: IG
authors.lastname: Steffen
authors.affiliation: Klinik für Gastroenterologie, Hepatologie und Infektiologie, Universitätsklinikum Magdeburg A.ö.R., Magdeburg, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Schütte
authors.affiliation: Klinik für Allgemein-, Viszeral-, und Gefäßchirurgie, Universitätsklinikum Magdeburg A.ö.R., Magdeburg, Germany; and.
authors.forename: Jörg
authors.initials: J
authors.lastname: Arend
authors.affiliation: Klinik für Radiologie und Nuklearmedizin, Universitätsklinikum Magdeburg A.ö.R., Magdeburg, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Ulrich
authors.affiliation: Klinik für Nieren- und Hochdruckkrankheiten, Diabetologie, und Endokrinologie, Universitätsklinikum Magdeburg A.ö.R., Magdeburg, Germany.
authors.forename: Silke
authors.initials: S
authors.lastname: Klose
authors.affiliation: Klinik für Gastroenterologie, Hepatologie und Infektiologie, Universitätsklinikum Magdeburg A.ö.R., Magdeburg, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Bornschein
authors.affiliation: Klinik für Radiologie und Nuklearmedizin, Universitätsklinikum Magdeburg A.ö.R., Magdeburg, Germany.
authors.forename: Ivalya
authors.initials: I
authors.lastname: Apostolova
authors.affiliation: Klinik für Radiologie und Nuklearmedizin, Universitätsklinikum Magdeburg A.ö.R., Magdeburg, Germany holger.amthauer@med.ovgu.de.
authors.forename: Holger
authors.initials: H
authors.lastname: Amthauer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D005770:Gastrointestinal Neoplasms / Q000000981:diagnostic imaging*; D006801:Humans; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging*; D015588:Observer Variation; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D017481:Receptors, Somatostatin / Q000378:metabolism*; D012015:Reference Standards; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D051598:Whole Body Imaging
chemical_list: D019275:Radiopharmaceuticals; D017481:Receptors, Somatostatin
keywords: SPECT/CT; multiphase CT; neuroendocrine neoplasm; scintigraphy; somatostatin receptor