title: Peptide receptor imaging in neuroendocrine tumors: comparison between diagnostic scintigraphy and post-therapy whole-body scan.
abstract: OBJECTIVE
  Several different somatostatin analogs labeled with gamma or positron-emitting radionuclides exist for diagnostic imaging of neuroendocrine tumors (NETs). Differences between standard diagnostic scintigraphy (SDS) and post-therapy whole-body scan (PTWBS) at peptide receptor radionuclide therapy in lesion detection are known; such differences have been correlated with the varying degree of receptor subtype expression and the varying receptor affinity profile of the different ligands. The aim of this study is to investigate differences between SDS and PTWBS obtained using the same radiopharmaceutical.
  
  
  METHODS
  We retrospectively reviewed clinical records of 53 patients with a diagnosis of NET, who underwent both SDS and PTWBS using (111)In-Pentetreotide. We compared the number of lesions for each body region detected by SDS and PTWBS.
  
  
  RESULTS
  In 14/53 patients (26.4%) discrepancies between SDS and PTWBS were found. PTWBS detected 68 additional lesions with respect to SDS that were distributed as follows: head and neck, 6; mediastinum, 1; liver, 10; abdomen/pelvis, 1; bone, 44; other localizations, 6. The number of lesions detected by SDS was significantly different from that revealed by PTWBS (Wilcoxon matched pairs test, P = 0.0313). The regions that contributed significantly to reach this difference were head and neck (McNemar test, P = 0.0412), liver (McNemar test, P = 0.0044), bone (McNemar test, P < 0.0001) and other localizations (McNemar test, P = 0.0412).
  
  
  CONCLUSIONS
  PTWBS shows more lesions than SDS with a significant discrepancy. We suppose that administration of higher radiopharmaceutical activity, use of larger peptide amount and the different time interval between radiopharmaceutical administration and scan execution can determine a higher sensitivity of PTWBS.
authors.affiliation: Department of Biomedical Sciences and of Morphologic and Functional Images, University of Messina, Messina, Italy. fminutoli@unime.it
authors.forename: Fabio
authors.initials: F
authors.lastname: Minutoli
authors.forename: Astrid
authors.initials: A
authors.lastname: Herberg
authors.forename: Alessandro
authors.initials: A
authors.lastname: Sindoni
authors.forename: Davide
authors.initials: D
authors.lastname: Cardile
authors.forename: Mariapaola
authors.initials: M
authors.lastname: Cucinotta
authors.forename: Sergio
authors.initials: S
authors.lastname: Baldari
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging* / Q000378:metabolism* / Q000628:therapy; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D017481:Receptors, Somatostatin / Q000378:metabolism*; D012189:Retrospective Studies; D051598:Whole Body Imaging
chemical_list: D019275:Radiopharmaceuticals; D017481:Receptors, Somatostatin