Relevance of the POS-1 orthotopic model as an "imaging model" for in vivo and simultaneous monitoring of tumor proliferation and bone remodeling in osteosarcoma.
BACKGROUND
Osteosarcoma (OS) management requires a better understanding of tumor/bone interactions in vivo during disease progression. Using [(18)F]-FDG and [(99m)Tc]-HMDP imaging, we assessed a methodology for an in vivo quantitative characterization of an orthotopic model of osteolytic OS on the basis of (1) tumor proliferation, (2) tumor and bone metabolic activities, and (3) bone remodeling.


METHODS
POS-1 tumor bearing mice were monitored in vivo over a 26-day period, with tumor and bone metabolic volumes (TMV and BMV, respectively) being determined from [(18)F]-FDG, bone remodeling from [(99m)Tc]-HMDP, and tumoral volume from micro- computed tomography scans.


RESULTS
From day 10, [(18)F]-FDG strongly accumulated within POS-1 tumor, with a tumor/muscle ratio of 3.7 ± 0.8. TMV and BMV increased as pathology progressed: TMV increased at early stage of pathology (from 56%) whereas BMV strongly increased (from 113%) during late stage. From [(99m)Tc]-HMDP imaging, bone remodeling features were evidenced within the distal region of tibia bearing the tumor, with a mean scintigraphic ratio of 1.36 ± 0.11 at day 12, that reached value of 2.53 ± 0.19 at day 26.


CONCLUSIONS
Our results validated the POS-1 orthotopic model as "OS imaging model," that could serve for evaluating in vivo therapies targeting tumor proliferation and/or bone remodeling in OS.
UMR 990 INSERM/Clermont-1 University, Clermont-Ferrand, France. elisabeth.noirault@inserm.fr
Elisabeth
E
Miot-Noirault
François
F
Gouin
Marie-Mélanie
MM
Dauplat
Dominique
D
Heymann
Jean-Michel
JM
Chezal
Françoise
F
Redini
D000818:Animals; D001859:Bone Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D016723:Bone Remodeling / Q000502:physiology*; D048708:Cell Growth Processes / Q000502:physiology; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D012516:Osteosarcoma / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D013669:Technetium Tc 99m Medronate / Q000031:analogs & derivatives / Q000493:pharmacokinetics
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; C024226:technetium Tc 99m hydroxymethylene diphosphonate; D013669:Technetium Tc 99m Medronate