title: Bone metastases in patients with neuroendocrine tumor: 68Ga-DOTA-Tyr3-octreotide PET in comparison to CT and bone scintigraphy.
abstract: Somatostatin receptor scintigraphy is an accurate imaging modality for the diagnosis of neuroendocrine tumor. Because detection of distant metastases has a major impact on treatment, early diagnosis of metastatic spread is of great importance. So far, no standard procedure has become established for the early diagnosis of bone metastases from neuroendocrine tumor. We compared the diagnostic value of CT with that of the novel somatostatin analog (68)Ga-1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid-d-Phe(1)-Tyr(3)-octreotide ((68)Ga-DOTATOC) in the detection of such metastases.
  
  
  METHODS
  Fifty-one patients (22 women and 29 men; age range, 32-87 y) with histologically verified neuroendocrine tumor were included in this study. PET scans were fused with CT scans using a vacuum fixation device. (18)F-NaF or (99m)Tc-dicarboxypropane diphosphonate bone scans or clinical follow-up served as the reference standard.
  
  
  RESULTS
  Twelve of the 51 patients had no evidence of bone metastases on any of the available imaging modalities, and 37 patients had (68)Ga-DOTATOC PET results true-positive for bone metastases. (68)Ga-DOTATOC PET results were true-negative for 12 patients, false-positive for one, and false-negative for another, resulting in a sensitivity of 97% and a specificity of 92%. (68)Ga-DOTATOC PET detected bone metastases at a significantly higher rate than did CT (P < 0.001). Furthermore, conventional bone scans confirmed the results of somatostatin receptor PET but did not reveal additional tumors in any patients.
  
  
  CONCLUSIONS
  (68)Ga-DOTATOC PET is a reliable, novel method for the early detection of bone metastases in patients with neuroendocrine tumor. Our results show that CT and conventional bone scintigraphy are less accurate than (68)Ga-DOTATOC PET in the primary staging or restaging of neuroendocrine tumor.
authors.affiliation: Department of Nuclear Medicine, Innsbruck Medical University, Innsbruck, Austria. daniel.putzer@i-med.ac.at
authors.forename: Daniel
authors.initials: D
authors.lastname: Putzer
authors.forename: Michael
authors.initials: M
authors.lastname: Gabriel
authors.forename: Benjamin
authors.initials: B
authors.lastname: Henninger
authors.forename: Dorota
authors.initials: D
authors.lastname: Kendler
authors.forename: Christian
authors.initials: C
authors.lastname: Uprimny
authors.forename: Georg
authors.initials: G
authors.lastname: Dobrozemsky
authors.forename: Clemens
authors.initials: C
authors.lastname: Decristoforo
authors.forename: Reto Josef
authors.initials: RJ
authors.lastname: Bale
authors.forename: Werner
authors.initials: W
authors.lastname: Jaschke
authors.forename: Irene Johanna
authors.initials: IJ
authors.lastname: Virgolini
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000175:diagnosis* / Q000556:secondary*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000175:diagnosis* / Q000556:secondary*; D015282:Octreotide / Q000031:analogs & derivatives*; D009942:Organometallic Compounds; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: C499142:Ga(III)-DOTATOC; D009942:Organometallic Compounds; D019275:Radiopharmaceuticals; D015282:Octreotide