title: Use of PET/CT and Stereotactic Radiation Therapy for the Diagnosis and Treatment of Osteosarcoma Metastases.
abstract: This case report describes the use of two new concepts in the diagnosis and treatment of metastatic osteosarcoma (OSA) in one dog. The dog was initially presented for positron emission tomography and computed tomography (PET/CT) as full-body staging following amputation and adjuvant chemotherapy for treatment of OSA of the proximal tibia. The initial PET/CT did not show evidence of metastatic disease. Six mo after OSA, diagnosis pulmonary metastatic nodules were identified and oral toceranib phosphate was initiated. Twelve mo postdiagnosis the dog developed neck pain and non-ambulatory tetraparesis and was diagnosed with a C7 vertebral metastatic lesion based on magnetic resonance imaging. A second PET/CT was performed to screen for further metastatic lesions, and a nodule within the right ischium was identified. The C7 and ischial lesions were treated with stereotactic radiation therapy (SRT). Sixteen mo postdiagnosis, a third PET/CT was performed due to increasing size of the pulmonary nodules and a right-sided liver metastasis was detected. The liver mass was treated with SRT. The PET/CT scans facilitated identification of gross metastatic lesions that were subsequently treated with SRT, which resulted in clinical improvement of the dog's neurological signs.
authors.affiliation: From the Flint Animal Cancer Center, Department of Clinical Sciences (L.E.S., S.J.W.), and the Department of Environmental and Radiological Health Sciences (L.R.G., M.W.N., J.C., E.R.), Colorado State University, Fort Collins, Colorado.
authors.forename: Laura Elizabeth
authors.initials: LE
authors.lastname: Selmic
authors.affiliation: From the Flint Animal Cancer Center, Department of Clinical Sciences (L.E.S., S.J.W.), and the Department of Environmental and Radiological Health Sciences (L.R.G., M.W.N., J.C., E.R.), Colorado State University, Fort Collins, Colorado.
authors.forename: Lynn R
authors.initials: LR
authors.lastname: Griffin
authors.affiliation: From the Flint Animal Cancer Center, Department of Clinical Sciences (L.E.S., S.J.W.), and the Department of Environmental and Radiological Health Sciences (L.R.G., M.W.N., J.C., E.R.), Colorado State University, Fort Collins, Colorado.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Nolan
authors.affiliation: From the Flint Animal Cancer Center, Department of Clinical Sciences (L.E.S., S.J.W.), and the Department of Environmental and Radiological Health Sciences (L.R.G., M.W.N., J.C., E.R.), Colorado State University, Fort Collins, Colorado.
authors.forename: James
authors.initials: J
authors.lastname: Custis
authors.affiliation: From the Flint Animal Cancer Center, Department of Clinical Sciences (L.E.S., S.J.W.), and the Department of Environmental and Radiological Health Sciences (L.R.G., M.W.N., J.C., E.R.), Colorado State University, Fort Collins, Colorado.
authors.forename: Elissa
authors.initials: E
authors.lastname: Randall
authors.affiliation: From the Flint Animal Cancer Center, Department of Clinical Sciences (L.E.S., S.J.W.), and the Department of Environmental and Radiological Health Sciences (L.R.G., M.W.N., J.C., E.R.), Colorado State University, Fort Collins, Colorado.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Withrow
mesh_terms: D000818:Animals; D001859:Bone Neoplasms / Q000175:diagnosis / Q000628:therapy / Q000662:veterinary*; D004283:Dog Diseases / Q000175:diagnosis* / Q000628:therapy*; D004285:Dogs; D012516:Osteosarcoma / Q000175:diagnosis / Q000628:therapy / Q000662:veterinary*; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods / Q000662:veterinary*; D049268:Positron-Emission Tomography; D016634:Radiosurgery