Imaging Trial: 18F- fluoroestradiol (FES) PET/CT for Breast Cancer

Name of Clinical Trial: 18F- fluoroestradiol (FES) PET/CT for Breast Cancer/NCT04883814

Summary: This phase 2 clinical trial is assessing the clinical value of using 18F- fluoroestradiol (FES) PET/CT for staging and detection of disease recurrence in patients with ER-positive breast cancer, as compared to the National Comprehensive Cancer Network’s (NCCN) recommended standard-of-care, which uses CT of the chest/abdomen/pelvis and bone scan.

California and American flag with word Imaging below it, Completed Enrollment above, and title of a clinical trial Two cohorts will be evaluated:

  1. Patients with advanced local breast cancer (stage 2B-3C) that will undergo standard of care imaging (CT + bone scan) to evaluate for unsuspected distant metastases.
  2. Patients with suspicion for breast cancer recurrence that will undergo standard of care imaging (CT + bone scan) to evaluate for disease recurrence.

In both cohorts, FES PET/CT will be obtained and compared with standard of care imaging. Whether seen on standard of care imaging or the FES PET/CT, lesions suspicious for unsuspected distant metastases (cohort #1) or the site of disease recurrence (cohort #2) will be selected for biopsy, per the clinical standard of care, to confirm disease that would warrant altering patient management. Pathology will be used as the reference standard for confirming malignancy.

Eligible patients: Patients with estrogen receptor positive (ER+) invasive ductal or invasive lobular carcinomas in two cohorts: 1) at initial diagnosis, (stage 2B-3C) and 2) treated patients with suspicion of recurrence. THIS TRIAL HAS COMPLETED ENROLLMENT.

Why is this study Important: FES PET/CT is a novel method of detecting ER+ malignancies. If FES PET/CT can more sensitively detect extent of disease than current standard of care imaging methods, then patients will be more accurately staged, and the most beneficial treatment options can be selected.

Background: The standard of care imaging of breast cancer metastases recommended by the NCCN, CT and bone scan, may be suboptimal. 18F-fluorestradiol (FES) is a novel PET tracer designed to detect estrogen receptors, which are often expressed in breast cancers. FES PET/CT may provide improved evaluation of metastases in patients with ER-positive breast cancer. Improved staging and/or detection of disease/disease recurrence could result in improved treatment decisions for tens of thousands of patients with ER-positive breast cancer.

Principal Investigator: Gary Ulaner, MD, PhD, FACNM; Director, Molecular Imaging and Therapy, Hoag Family Cancer Institute

Clinical Trial location: Hoag Family Cancer Institute, Irvine, California (Open to any eligible patient willing to be seen at Hoag Family Cancer Institute)

How to learn more about whether participating in this trial is right for you:

Note,  THIS TRIAL HAS COMPLETED ENROLLMENT. Contact Beth Thomsen, BS, Clinic Coordinator at or Gary Ulaner, MD, PhD, FACNM, Director at

More Information:

To learn more about FES PET Imaging:

The Lobular Breast Cancer Alliance shares information about ongoing clinical for lobular breast cancer. LBCA does not sponsor or run the clinical trials, and the scientific validity and safety of the trials is the responsibility of the trial investigators. Learn more by contacting the clinical trial coordinators listed above directly.

Patients should always discuss their participation in any clinical trial directly with their doctor – these Questions to Ask your Doctor may help. Learn more about participating in clinical trials.  Learn about other lobular breast cancer clinical trials and studies.

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