title: Fusion of [(18)F]FDG PET with fluorescence diffuse optical tomography to improve validation of probes and tumor imaging.
abstract: OBJECTIVE
  Given the progress of fluorescence diffuse optical tomography (fDOT) technology, here, we study the additional benefits provided by multimodal PET/fDOT imaging by comparing the biodistribution of 2-deoxy-2-[(18)F]fluoro-D-glucose ([(18)F]FDG) in tumors with three fluorescent probes: a glucose analog, a protease activatable optical probe, and a ligand of αvβ3 integrin.
  
  
  METHODS
  Sequential fDOT/PET/computed tomography (CT) imaging of mice was performed with a custom multimodal mouse support that allows the subject to be transferred between the fDOT and the PET/CT scanners. Experiments were performed in xenografted tumor models derived from the human breast cancer line MDA-MB 231 and compared to ex vivo analysis.
  
  
  RESULTS
  The three-dimensional signals showed that the fluorescent glucose analog is not colocalized with [(18)F]FDG, raising questions about its use as a surrogate probe of the PET tracer. Fusion of [(18)F]FDG with the other fluorescent probes showed evidence of high variability both for the protease activity and the αvβ3 integrin expression during tumor growth.
  
  
  CONCLUSIONS
  The added value of hybrid PET/fDOT over the two modalities was demonstrated for cross-validation of probes and for better characterization of tumor models.
authors.affiliation: CEA, Institut d'Imagerie Biomédicale, Service Hospitalier Frédéric Joliot, Orsay Cedex, France.
authors.forename: Anikitos
authors.initials: A
authors.lastname: Garofalakis
authors.forename: Albertine
authors.initials: A
authors.lastname: Dubois
authors.forename: Benoît
authors.initials: B
authors.lastname: Thézé
authors.forename: Bertrand
authors.initials: B
authors.lastname: Czarny
authors.forename: Bertrand
authors.initials: B
authors.lastname: Tavitian
authors.forename: Frédéric
authors.initials: F
authors.lastname: Ducongé
mesh_terms: D000818:Animals; D002403:Cathepsins / Q000378:metabolism; D045744:Cell Line, Tumor; D004058:Diffusion; D005456:Fluorescent Dyes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D051379:Mice; D015335:Molecular Probes; D009369:Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D009842:Oligopeptides; D049268:Positron-Emission Tomography / Q000379:methods*; D015203:Reproducibility of Results; D014018:Tissue Distribution; D041622:Tomography, Optical / Q000379:methods*
chemical_list: D005456:Fluorescent Dyes; D015335:Molecular Probes; D009842:Oligopeptides; D019788:Fluorodeoxyglucose F18; C047981:arginyl-glycyl-aspartic acid; D002403:Cathepsins