Maximum standardized uptake value on ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography improves...

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 (SUV_max) was calculated. To evaluate the predictability of SUV_max for Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) grade 3, receiver operating characteristics (ROC) curve analysis was performed. To analyze whether SUV_max 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 < 0.001), with a cut-off point of 4.5 SUV_max showing 85.7% sensitivity and 78.3% specificity. Cox analyses showed that SUV_max > 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). SUV_max is highly predictive of FNCLCC grade 3 and SUV_max > 4.5 can be used as a prognostic factor before obtaining the histopathology.