title: (68)Ga-AMBA and (18)F-FDG for preclinical PET imaging of breast cancer: effect of tamoxifen treatment on tracer uptake by tumor.
abstract: BACKGROUND
  AMBA is a bombesin analogue that binds to GRPr. In a mouse model of estrogen-dependent human breast cancer, we tested whether (68)Ga-AMBA can be used for PET detection of GRPr-expressing tumors and could be more accurate than (18)F-FDG to monitor tumor response to hormone therapy.
  
  
  METHODS
  The radiolabeling of (68)Ga-AMBA was automated using a R&D Synchrom module. ZR75-1, a breast cancer cell line, was xenografted in nude mice. (68)Ga-AMBA tumor uptake was compared with that of (18)F-FDG before and after treatment with tamoxifen.
  
  
  RESULTS
  AMBA was (68)Ga-radiolabelled in 30min with 95.3% yield and purity≥98%. Prior to treatment, (68)Ga-AMBA was highly concentrated into tumors (tumor to non-tumor ratio=2.4 vs. 1.3 with (18)F-FDG). With tamoxifen treatment (n=6) (68)Ga-AMBA uptake plateaued after 1week and decreased after 2weeks, with a significant reduction compared to controls (n=4). In contrast the effect of tamoxifen treatment could not be appreciated using (18)F-FDG.
  
  
  CONCLUSIONS
  (68)Ga-AMBA appeared better than (18)F-FDG to visualize and monitor the response to hormone treatment in this breast cancer model.
authors.affiliation: Plateforme LIMP, UMS28 Phénotypage du petit animal, UPMC, Paris, France. Electronic address: aurelie.prignon@upmc.fr.
authors.forename: A
authors.initials: A
authors.lastname: Prignon
authors.affiliation: Plateforme LIMP, UMS28 Phénotypage du petit animal, UPMC, Paris, France; APHP, Hôpital Tenon, Médecine nucléaire, Paris, France.
authors.forename: V
authors.initials: V
authors.lastname: Nataf
authors.affiliation: Plateforme LIMP, UMS28 Phénotypage du petit animal, UPMC, Paris, France.
authors.forename: C
authors.initials: C
authors.lastname: Provost
authors.affiliation: Bracco Research USA, Princeton USA.
authors.forename: A
authors.initials: A
authors.lastname: Cagnolini
authors.affiliation: Plateforme LIMP, UMS28 Phénotypage du petit animal, UPMC, Paris, France; APHP, Hôpital Tenon, Médecine nucléaire, Paris, France.
authors.forename: F
authors.initials: F
authors.lastname: Montravers
authors.affiliation: Inserm, U773, Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: Gruaz-Guyon
authors.affiliation: Bracco Research USA, Princeton USA.
authors.forename: L E
authors.initials: LE
authors.lastname: Lantry
authors.affiliation: Plateforme LIMP, UMS28 Phénotypage du petit animal, UPMC, Paris, France; APHP, Hôpital Tenon, Médecine nucléaire, Paris, France.
authors.forename: J N
authors.initials: JN
authors.lastname: Talbot
authors.affiliation: Bracco Research USA, Princeton USA.
authors.forename: A D
authors.initials: AD
authors.lastname: Nunn
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D049109:Cell Proliferation / Q000187:drug effects; D002471:Cell Transformation, Neoplastic; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism* / Q000493:pharmacokinetics; D005710:Gallium Radioisotopes; D006801:Humans; D051379:Mice; D009842:Oligopeptides / Q000378:metabolism* / Q000493:pharmacokinetics; D049268:Positron-Emission Tomography; D013629:Tamoxifen / Q000494:pharmacology*; D047368:Tumor Burden / Q000187:drug effects
chemical_list: C512446:DO3A-CH2CO-G-4-aminobenzoyl-Q-W-A-V-G-H-L-M-NH2; D005710:Gallium Radioisotopes; D009842:Oligopeptides; D013629:Tamoxifen; D019788:Fluorodeoxyglucose F18
keywords: (18)F-FDG; (68)Ga; Breast cancer; Estrogen; Gastrin releasing peptide receptor; PET