[18F]FES PET/.CT in Uterine Cancer

Inclusion Criteria 1. Participants will be ≥ 18 years of age 2. Recurrent or metastatic or intact non-operated uterine cancer not treated with surgery that is biopsy-proven or demonstrated on other standard of care imaging (e.g. CT, FDG PET/CT, MRI, bone scan, x-ray, ultrasound) 3. At least one lesion outside the liver detected by standard of care imaging (e.g.CT, FDG PET/CT, MRI, bone scan, x-ray, ultrasound) 4. Participants must be informed of the investigational nature of this study and be willing to provide written informed consent and participate in this study in accordance with institutional and federal guidelines prior to study-specific procedures. 5. Subjects that are currently on or have recently discontinued tamoxifen or fulvestrant would require an 8-week or 28-week, respectively, washout period prior to FES PET/CT scan. Exclusion Criteria 1. Females who report they are pregnant at screening will not be eligible for this study. A urine pregnancy test will be performed in women of child-bearing potential prior to FES injection. 2. Inability to tolerate imaging procedures in the opinion of an investigator or treating physician 3. Any current medical condition, illness, or disorder as assessed by medical record review and/or self-reported that is considered by a physician investigator to be a condition that could compromise participant safety or successful participation in the study