title: Treatment with octreotide does not reduce tumor uptake of (68)Ga-DOTATATE as measured by PET/CT in patients with neuroendocrine tumors.
abstract: We hypothesized that (68)Ga-DOTATATE uptake of neuroendocrine tumors is sensitive to therapy with a nonradioactive somatostatin analog.
  
  
  METHODS
  (68)Ga-DOTATATE PET/CT was used to examine 105 patients, 35 of whom had been pretreated with long-acting octreotide. The maximum standardized uptake value (SUV(max)) of target tissues, as well as metastases, was compared between the groups of patients with (group 1) and without (group 2) octreotide treatment.
  
  
  RESULTS
  The SUV(max) of the spleen and liver was significantly lower in group 1 than in group 2 (both P < 0.001). There were no significant group differences in SUV(max) for primary tumors (28.6 ± 6.8 vs. 32.9 ± 31.5) or metastases in the liver (27.2 ± 14.8 vs. 25.7 ± 10.7), lymph nodes (41.4 ± 19.5 vs. 25.0 ± 6.3), or skeleton (39.5 ± 22.0 vs. 15.4 ± 7.8). In 9 patients available for intraindividual comparison, tumor uptake was unaffected by treatment with somatostatin analogs (21.7 vs. 20.6; P = 0.93).
  
  
  CONCLUSIONS
  Treatment with a long-acting somatostatin analog did not significantly reduce (68)Ga-DOTATATE binding in neuroendocrine tumors but tended to improve the tumor-to-background ratio.
authors: Department of Nuclear Medicine, Ludwig-Maximilians-University, Munich, Germany. Alexander.Haug@med.uni-muenchen.de
authors: Alexander R
authors: AR
authors: Haug
authors: Axel
authors: A
authors: Rominger
authors: Mona
authors: M
authors: Mustafa
authors: Christoph
authors: C
authors: Auernhammer
authors: Burkhard
authors: B
authors: Göke
authors: Gerwin P
authors: GP
authors: Schmidt
authors: Björn
authors: B
authors: Wängler
authors: Paul
authors: P
authors: Cumming
authors: Peter
authors: P
authors: Bartenstein
authors: Marcus
authors: M
authors: Hacker
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001692:Biological Transport / Q000187:drug effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009362:Neoplasm Metastasis; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D015282:Octreotide / Q000494:pharmacology* / Q000627:therapeutic use; D009942:Organometallic Compounds / Q000378:metabolism*; D049268:Positron-Emission Tomography; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D009942:Organometallic Compounds; C513399:gallium Ga 68 dotatate; D015282:Octreotide