title: First ex vivo study demonstrating that 99mTc-NTP 15-5 radiotracer binds to human articular cartilage.
abstract: OBJECTIVE
  Preclinical data pointed to (99m)Tc-NTP 15-5 as a good candidate for single photon emission computed tomography (SPECT) imaging of cartilaginous disease. We set out to investigate and quantify (99m)Tc-NTP 15-5 ex vivo uptake by human articular cartilage relative to bone (99m)Tc-hydroxymethylene diphosphonate (HMDP) radiotracer.
  
  
  METHODS
  Three osteoarthritic human tibial plateaux and four tibiofemoral joints were incubated with (99m)Tc-NTP 15-5 and (99m)Tc-HMDP for 2 h. Affinity of tracers for cartilage was determined by visual analysis of SPECT/CT acquisitions and measurement of cartilage to cortical bone uptake ratios.
  
  
  RESULTS
  Cartilage to cortical bone uptake ratios were 3.90 ± 2.35 and 0.76 ± 0.24, respectively, for (99m)Tc-NTP 15-5 and (99m)Tc-HMDP radiotracers. Visual analysis of fused SPECT/CT slices showed selective, intense (99m)Tc-NTP 15-5 accumulation in articular cartilage, whereas (99m)Tc-HMDP binding was low. Interestingly, a cartilage defect visualized on CT was clearly associated with focal decreased uptake of (99m)Tc-NTP 15-5.
  
  
  CONCLUSIONS
  The tracer (99m)Tc-NTP 15-5 is of major interest for human cartilage molecular imaging and could find clinical applications in osteoarthritis staging and monitoring.
authors.affiliation: Nuclear Medicine Department, Jean Perrin Cancer Centre, Clermont-Ferrand, France. florent.cachin@cjp.fr
authors.forename: Florent
authors.initials: F
authors.lastname: Cachin
authors.forename: Stéphane
authors.initials: S
authors.lastname: Boisgard
authors.forename: Aurélien
authors.initials: A
authors.lastname: Vidal
authors.forename: Marc
authors.initials: M
authors.lastname: Filaire
authors.forename: Philippe
authors.initials: P
authors.lastname: Auzeloux
authors.forename: Damien
authors.initials: D
authors.lastname: Culot
authors.forename: Serge
authors.initials: S
authors.lastname: Askienazy
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Madelmont
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Chezal
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Miot-Noirault
mesh_terms: D001692:Biological Transport; D002358:Cartilage, Articular / Q000000981:diagnostic imaging / Q000378:metabolism*; D006573:Heterocyclic Compounds, 1-Ring / Q000378:metabolism*; D006801:Humans; D064847:Multimodal Imaging; D015609:Organotechnetium Compounds / Q000378:metabolism*; D049268:Positron-Emission Tomography; D000644:Quaternary Ammonium Compounds / Q000378:metabolism*; D011829:Radiation Dosage; D011849:Radioactive Tracers; D013977:Tibia / Q000000981:diagnostic imaging / Q000378:metabolism; D014057:Tomography, X-Ray Computed
chemical_list: D006573:Heterocyclic Compounds, 1-Ring; C407019:N-(triethylammonium)-3-propyl(15)ane-N5; D015609:Organotechnetium Compounds; D000644:Quaternary Ammonium Compounds; D011849:Radioactive Tracers