PET/CT, an important imaging modality in the management of sarcoma patients

Abstract

Sarcomas are a heterogeneous group of malignant tumors of mesenchymal origin. 18 Fluorodeoxyglucose (FDG)-Positron Emission Tomography (PET)/Computed Tomography (CT) is a combined imaging modality that could provide an anatomic and functional assessment of many solid tumors. In this study, the association between primary tumor characteristics (grade, histologic type, stage, localization) and the FDG-PET/ CT data of the primary tumor at the diagnosis were evaluated. The study aimed to determine the diagnostic role of numerical metabolic values determined in PET/CT in predicting grade, prognosis, and other patient characteristics of sarcoma patients. Patients with soft tissue and bone sarcoma who applied to the oncology department of Gazi University Faculty of Medicine between 2000 and 2014 were evaluated retrospectively. All patients underwent PET imaging with FDG before initiation of neoadjuvant chemotherapy or resection. Sarcoma patients (27 soft tissue, 18 bone sarcoma) were evaluated retrospectively in this study. Tumor size was found to correlate with SUVmax. Histologic grade was found to be associated with tumor 18F-FDG, but this was not statistically significant because of the small patient number. The optimal cut-off SUVmax value in showing the difference between low and high grades was 5.5. Overall survival was shown to be shorter in patients with SUVmax ≥5.5. In this study, we aimed to show the relationship between histologic grade and tumor metabolic activity. PET-CT could give an idea about tumor histologic grade and predict survival. It has an important role in diagnosis and also in determining the prognosis.