The prognostic significance of metabolic tumour volume and total lesion glycolysis for dogs staged for appendicular osteosarcoma with fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography.

Abstract

Metabolic tumour volumes (MTV) and total lesion glycolysis (TLG) are metabolic parameters that are becoming more commonly reported in human medicine to quantify tumours detected on fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-FDG PET/CT). In this retrospective study dogs afflicted with appendicular osteosarcoma that were staged withF-FDG PET/CT had MTV and TLG at a variety of set and fixed thresholds calculated by two observers. These values, along with SUV, were evaluated for prognostic significance in this population of dogs. There was excellent correlation between two observers for all values. Multiple volumetric parameters were significantly associated with survival. SUVhad the highest sensitivity for survival and TLG at 2.5 SUV*cmhad the highest specificity for prediction of survival based on ROC calculations. The SUV, MTV at 2.5 SUV and TLG at 2.5 SUV*cmwere significantly different between dogs that survived more than or less than 1 year. This study is the first of its kind in veterinary medicine that retrospectively evaluated volumetric tumour values for prognostic significance and may provide a basis for standardized method of reportingF-FDG PET/CT results.