Prognostic value of fluorineflourodeoxyglucose positron emission tomography/computed tomography in dogs with appendicular osteosarcoma.

Abstract

BACKGROUND: Factors indicative of a negative prognosis for appendicular osteosarcoma (OSA) in dogs are visible metastatic disease, location, and size of lesion. In human medicine maximum standard uptake value (SUV), as measured on a fluorineflourodeoxyglucose positron emission tomography/computed tomography (F-FDG PET/CT), is prognostic for survival for several tumor types. OBJECTIVE: Determine if SUVis associated with progression-free interval (PFI) and determination of survival in dogs with appendicular OSA. ANIMALS: Sixty-two dogs with untreated appendicular OSA that had been staged withF-FDG PET/CT. METHODS: Retrospective analysis of theF-FDG PET/CT was performed. Dogs were excluded from the study if they did not receive definitive intent treatment for their primary OSA and adjuvant chemotherapy with carboplatin, or had visible metastatic disease on initial imaging. A region of interest (ROI) was created around the primary tumor to measure SUV. Univariable and multivariable Cox proportional hazards analysis was performed to evaluate for associations between variables including SUVand outcome of PFI and overall survival (OS). RESULTS: Maximum standard uptake value of the primary tumor was significantly associated with the OS (P&#x2009;=&#x2009;.04) with adjustment for treatment type and monocyte count. The overall median survival time (OST) was 284&#x2009;days (range, 39-1293&#x2009;days) with the OST of dogs having an SUVof &#x2265;7.4 of 254&#x2009;days (range, 98-428&#x2009;days) and dogs with an SUVof <7.4 of 680&#x2009;days (range, 108-811&#x2009;days, P&#x2009;=&#x2009;.01). CONCLUSIONS AND CLINICAL IMPORTANCE: Maximum standard uptake value as measured viaF-FDG PET/CT is significantly associated with survival in dogs with appendicular OSA with a high SUVbeing an indicator of a negative prognosis.