Preoperative <sup>18</sup>F-Fluorodeoxyglucose Positron Emission Tomography/CT in Prediction of Uterine Risk Factors and Lymph Node Metastasis: An Analysis of 111 Endometrioid Endometrial Cancer Patients

Introduction: This study evaluated the role of 18F-fluorodeoxyglucose (FDG) positron emission tomography/CT (PET/CT) in the detection of lymph node metastases and the association between uterine maximum standardized uptake values (SUVmax) and the histopathological features in endometrial cancer patients. Materials and Methods: Patients with endometrioid endometrial cancer underwent preoperative 18F-FDG PET/CT imaging and were staged surgically. 18F-FDG PET/CT findings were compared with final pathology reports. Grade 3 histology or grade 2 histology with myometrial invasion ≥50% was established as a high risk feature. Results: One hundred and eleven patients were analysed. Sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of 18F-FDG PET/CT in the detection of lymph node metastasis in all patients (n = 111) were 67, 96, 93, 60 and 97%, respectively. In the high-risk group, sensitivity, specificity, accuracy, PPV and NPV of 18F-FDG PET/CT were 75, 92, 91, 60 and 96%, respectively. Uterine SUVmax was found to be associated with myometrial invasion, grade and cervical stromal involvement. Conclusions:18F-FDG PET/CT has limited sensitivity and accuracy in detecting lymph node metastasis. Therefore, as of now, it is not accepted as a modality that can replace lymphadenectomy. SUVmax values can predict high-risk factors.