title: Searching for primaries in patients with neuroendocrine tumors (NET) of unknown primary and clinically suspected NET: Evaluation of Ga-68 DOTATOC PET/CT and In-111 DTPA octreotide SPECT/CT.
abstract: BACKGROUND
  To evaluate the clinical efficacy of In-111 DTPA octreotide SPECT/CT and Ga-68 DOTATOC PET/CT for detection of primary tumors in patients with either neuroendocrine tumor of unknown primary (NETUP) or clinically suspected primary NET (SNET).
  
  
  METHODS
  A total of 123 patients were included from 2006 to 2009, 52 received Ga-68 DOTATOC PET/CT (NETUP, 33; SNET, 19) and 71 underwent In-111 DTPA octreotide SPECT/CT (50; 21). The standard of reference included histopathology or clinical verification based on follow-up examinations.
  
  
  RESULTS
  In the NETUP group Ga-68 DOTATOC detected primaries in 15 patients (45.5%) and In-111 DTPA octreotide in 4 patients (8%) (p < 0.001); in the SNET group, only 2 primaries could be detected, all by Ga-68 DOTATOC. In patients with NETUP, primary tumors could be found significantly more often than in patients with SNET (p = 0.01). Out of these 21 patients 14 patients were operated.
  
  
  CONCLUSIONS
  Ga-68 DOTATOC PET/CT is preferable to In-111 DTPA octreotide SPECT/CT when searching for primary NETs in patients with NETUP but should be used with caution in patients with SNET.
authors.affiliation: Department of Nuclear Medicine, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany.
authors.forename: Nils Friedemann
authors.initials: NF
authors.lastname: Schreiter
authors.affiliation: Department of Nuclear Medicine, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany.
authors.forename: Ann-Mirja
authors.initials: AM
authors.lastname: Bartels
authors.affiliation: Department of Radiology, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany.
authors.forename: Vera
authors.initials: V
authors.lastname: Froeling
authors.affiliation: Department of Nuclear Medicine, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany.
authors.forename: Ingo
authors.initials: I
authors.lastname: Steffen
authors.affiliation: Department of Gastroenterology, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany.
authors.forename: Ulrich-Frank
authors.initials: UF
authors.lastname: Pape
authors.affiliation: Department of Radiology, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Beck
authors.affiliation: Department of Radiology, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Hamm
authors.affiliation: Department of Nuclear Medicine, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany.
authors.forename: Winfried
authors.initials: W
authors.lastname: Brenner
authors.affiliation: Department of Nuclear Medicine, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany ; Department of Radiology, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Röttgen
keywords: CUP; Ga-68 DOTATOC PET/CT; In-111 DTPA octreotide SPECT; NET; clinically suspected NET