title: Accuracy of radiography, nuclear scintigraphy, and histopathology for determining the proximal extent of distal radius osteosarcoma in dogs.
abstract: OBJECTIVE
  To compare the accuracy of radiography, nuclear scintigraphy, and histopathology for determining the proximal extent of distal radius osteosarcoma in dogs.
  
  
  METHODS
  Retrospective clinical study.
  
  
  METHODS
  Twenty client-owned dogs taken to Colorado State University with osteosarcoma of the distal radius.
  
  
  METHODS
  Medical records of 20 dogs with confirmed osteosarcoma that underwent a limb-salvage procedure were reviewed. Measurements were performed directly from the lateral view of each radius, from both the scintigram and the radiograph, to determine the length of the radius and the distance from the proximal extent of the tumor to the distal radiographic or scintographic extent of the radius. The ratio of distal radial involvement to total radius length was calculated. A similar ratio was also determined using the macroslide, which included the entire portion of bone that was excised during the limb-salvage procedure. All 3 methods of measurement were compared.
  
  
  RESULTS
  Nuclear scintigraphy significantly overestimated tumor length when compared with macroslide specimen measurements. Radiography also overestimated tumor length, but these results were not significantly different from macroslide specimen measurements.
  
  
  CONCLUSIONS
  Both radiography and nuclear scintigraphy overestimate the extent of distal radius osteosarcoma in dogs when compared with histopathologic macroslides of the same lesions. Nuclear scintigraphy overestimated tumor extent to a larger degree than did radiography.
  
  
  CONCLUSIONS
  Although radiography is a more accurate method of measurement of the extent of distal radius osteosarcoma, because nuclear scintigraphy overestimates tumor length to a greater degree, scintigraphy may provide a larger margin of safety for determining the site of proximal osteotomy during a limb-salvage procedure. However, caution should be taken when utilizing scintigraphy, because this method may overestimate length of radius involved to such an extent as to cause the surgeon to believe that a patient is not a suitable limb-salvage candidate.
authors.affiliation: Comparative Oncology Unit, Animal Cancer Center, Department of Veterinary Clinical Sciences, Colorado State University, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, CO 80523, USA.
authors.forename: N F
authors.initials: NF
authors.lastname: Leibman
authors.forename: C A
authors.initials: CA
authors.lastname: Kuntz
authors.forename: P F
authors.initials: PF
authors.lastname: Steyn
authors.forename: M J
authors.initials: MJ
authors.lastname: Fettman
authors.forename: B E
authors.initials: BE
authors.lastname: Powers
authors.forename: S J
authors.initials: SJ
authors.lastname: Withrow
authors.forename: W S
authors.initials: WS
authors.lastname: Dernell
mesh_terms: D000818:Animals; D001859:Bone Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D004283:Dog Diseases / Q000175:diagnosis* / Q000473:pathology; D004285:Dogs; D012516:Osteosarcoma / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D011859:Radiography / Q000662:veterinary*; D011877:Radionuclide Imaging / Q000662:veterinary*; D011884:Radius / Q000000981:diagnostic imaging / Q000473:pathology; D012189:Retrospective Studies