The Prognostic Value of Maximum Standardized Uptake Value (SUVmax) of 18F-FDG PET/CT for Risk Stratification and Outcome Prediction in Endometrial Cancer: A Retrospective Analysis

Background and objective Endometrial cancer, the most common gynecological malignancy in developed countries, is frequently diagnosed at an early stage due to the symptomatic presentation of irregular bleeding. We aimed to assess the prognostic value of preoperative PET/CT-derived maximum standardized uptake value (SUVmax) in patients with endometrial cancer and investigated its association with established clinical risk factors and survival outcomes. Methods We retrospectively analyzed 162 patients with endometrial cancer who underwent preoperative PET/CT at Kyorin University Hospital from December 2020 to June 2024. We recorded and assessed the SUVmax of primary uterine tumors against clinical histopathological findings, such as myometrial invasion, lymphovascular space invasion (LVSI), cervical stromal invasion, extrauterine lesions, and histological types. Patients were categorized into recurrence risk groups based on the Japan Society of Gynecologic Oncology (JSGO) 2023 guidelines. Statistical evaluations involved the Mann-Whitney U tests for group comparisons and Kaplan-Meier analysis for overall survival (OS) and progression-free survival (PFS). Results The median SUVmax of primary uterine tumors was 26.0. A higher SUVmax was significantly associated with myometrial invasion, LVSI, and larger tumor diameter (p<0.01). Significant differences in the SUVmax were observed among the various postoperative recurrence risk groups, with higher values observed in the intermediate- and high-risk groups (p<0.01). Kaplan-Meier survival analysis revealed that a higher SUVmax was significantly associated with poorer OS. Conclusions SUVmax derived from preoperative PET/CT can significantly predict endometrial cancer prognosis, correlating with clinical risk factors and OS. Hence, integrating SUVmax into preoperative assessments could enhance risk stratification and inform treatment planning. Prospective studies with larger cohorts are needed to validate these findings and establish standardized SUVmax cutoffs for clinical application.