Maximum standardized uptake value on 18F-fluorodeoxyglucose positron emission tomography/computed tomography improves outcome prediction in retroperitoneal liposarcoma.

While 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) has been investigated in extremity sarcomas, there is no evidence on its usefulness in retroperitoneal sarcoma. This study was designed to evaluate the usefulness of 18F-FDG PET/CT in predicting aggressiveness of retroperitoneal liposarcoma. Patients experienced surgery for retroperitoneal liposarcoma from November 2007 to February 2018 and underwent preoperative 18F-FDG PET/CT were included. Preoperative maximum standardized uptake value (SUVmax) was calculated. To evaluate the predictability of SUVmax for Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) grade 3, receiver operating characteristics (ROC) curve analysis was performed. To analyze whether SUVmax can be a risk factor for prognosis, multivariable Cox regression was performed including potential risk factors regarding operation and histopathology. A total of 133 patients were included. ROC curve showed area under the curve of 0.877 (P max showing 85.7% sensitivity and 78.3% specificity. Cox analyses showed that SUVmax > 4.5 was a significant factor for recurrence-free survival (HR = 2.148, CI 1.301-3.546, P = 0.003) and overall survival (HR = 5.052, CI 1.854-13.766, P = 0.002). SUVmax is highly predictive of FNCLCC grade 3 and SUVmax > 4.5 can be used as a prognostic factor before obtaining the histopathology.