title: Correlation of immunohistopathological expression of somatostatin receptor-2 in breast cancer and tumor detection with 68Ga-DOTATOC and 18F-FDG PET imaging in an animal model.
abstract: BACKGROUND
  Fludeoxyglucose positron emission topography ((18)F-FDG PET) is insufficiently sensitive at detecting small or low-grade breast tumors. The characterization of somatostatin receptors (SSTR) in tumors and the development of (68)Ga-DOTATOC PET for imaging could be of interest. The aim of this study was to validate an animal model expressing SSTR2 and to correlate the immunohistochemical (IHC) analysis with (18)F-FDG and (68)Ga-DOTATOC uptake in vivo.
  
  
  METHODS
  Ten nude mice were xenografted with the ZR-75-1 breast tumor cell line. Imaging was performed with (68)Ga-DOTATOC and (18)F-FDG and correlated to IHC analysis of SSTR2.
  
  
  RESULTS
  IHC analyses showed that the tumors expressed SSTR2. On PET imaging, the tumors were barely visible with (18)F-FDG, whereas with (68)Ga-DOTATOC, specific two-fold higher uptake was observed (p<0.005).
  
  
  CONCLUSIONS
  Our results suggest that (68)Ga-DOTATOC PET could be used for detection of breast tumors not detected with (18)F-FDG. SSTR2 status should be assessed to allow for individual treatment.
authors.affiliation: Department of Surgical Oncology, Institut Paoli Calmettes, 232 Boulevard de Sainte-Marguerite 13009 Marseille, France. elisabeth.chereau@gmail.com
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Chereau
authors.forename: Lucile
authors.initials: L
authors.lastname: Durand
authors.forename: Albane
authors.initials: A
authors.lastname: Frati
authors.forename: Aurelie
authors.initials: A
authors.lastname: Prignon
authors.forename: Jean-Noël
authors.initials: JN
authors.lastname: Talbot
authors.forename: Roman
authors.initials: R
authors.lastname: Rouzier
mesh_terms: D000818:Animals; D000912:Antibodies, Neoplasm / Q000378:metabolism; D045744:Cell Line, Tumor; D004195:Disease Models, Animal; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007150:Immunohistochemistry; D015674:Mammary Neoplasms, Animal / Q000000981:diagnostic imaging* / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D051379:Mice; D015282:Octreotide / Q000031:analogs & derivatives*; D009942:Organometallic Compounds; D049268:Positron-Emission Tomography; D017481:Receptors, Somatostatin / Q000276:immunology* / Q000378:metabolism
chemical_list: D000912:Antibodies, Neoplasm; C499142:Ga(III)-DOTATOC; D009942:Organometallic Compounds; D017481:Receptors, Somatostatin; C570769:somatostatin receptor 2, mouse; D019788:Fluorodeoxyglucose F18; D015282:Octreotide
keywords: 18F-FDG; 68Ga-DOTATOC; PET; SSTR2; immunohistochemistry; somatostatin analogs