Prognostic Value of Preoperative Imaging

Abstract

18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) increases the sensitivity for preoperative detection of lymph nodes and distant metastases in endometrial cancer. The objective of this investigation was to determine the prognostic value of preoperative PET-CT compared with computed tomography (CT) alone for high-risk endometrial carcinoma. We performed a retrospective review of high-risk histology endometrial cancer from 2008 to 2015. Clinical variables including surgical procedure, preoperative imaging modality, and outcome were collected. Survival analysis was performed utilizing the Kaplan-Meier and Cox proportional hazards methodologies. Of the 555 women treated for high-risk histology endometrial cancer, 88 (16%) had preoperative PET-CT, and 97 (17%) CT without PET available. PET-CT demonstrated positive findings in 37 women (42%) compared with 33 (30%) with preoperative CT alone. PET-CT had a positive predictive value of 96% for nodal metastasis compared with 60% for CT alone. The median follow-up time for the entire cohort was 59 months (range, 12 to 96 mo). Patients with a negative preoperative PET-CT (n=54) had a median progression-free survival (PFS) that was not reached, whereas the median PFS in the PET-CT positive group was 13 months (n=34). Women with a negative PET-CT had a longer median overall survival (OS) not yet reached compared with 34 months in the PET-CT positive cohort (hazard ratio, 2.4; P<0.001). CT findings did not associate with PFS or OS. PET-CT demonstrated superior sensitivity for lymph node metastasis and detecting distant disease compared with CT. Preoperative PET-CT, whether positive or negative, offered OS and PFS prognostic value not observed with CT alone.