FES PET/MRI for Occult Disease in Lobular Breast Cancer

October 30, 2026 updated by: University of Wisconsin, Madison

A Diagnostic Accuracy Study of FES PET/MRI for the Detection of Occult Disease in Lobular Breast Cancer

The investigators hope to learn if lobular breast cancer can be identified using a special procedure called a positron emission tomography (PET) magnetic resonance image (MRI) scan, collectively a PET/MRI scan, that uses a radioactive imaging agent called Fluorine 18 fluoroestradiol (18F-FES). This procedure may be able to define the extent of disease more clearly than the standard of care breast imaging exams. 30 participants will be enrolled and be on study for up to 6 months.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

This prospective study aims to estimate the added value of supplemental 18F-FES PET/MRI following standard-of-care (SOC) preoperative assessments for detecting occult disease in ILC. The investigators hypothesize that there is increased sensitivity of 18F-FES PET/MRI for detecting additional locoregional and distant site(s) of disease that is occult on SOC imaging.

Primary Objective: To estimate the increased sensitivity of 18F-FES PET/MRI for detecting disease that is occult on SOC imaging

Secondary Objectives: To characterize the

  • Positive predictive value of additional pathology-confirm disease.
  • Proportion of upstaging (composite T, N and M stages)
  • Frequency of extensive breast disease (e.g., multifocal, multicentric or contralateral).
  • Change in clinical management (e.g., changes in treatment intent, conversion to neoadjuvant therapy).
  • Agreement of ILC tumor size between imaging exams (18F FES PET-MRI and SOC breast MRI, ultrasound and mammogram) and histopathologic exams.
  • Error rate in size measurements between radiology and pathology for primary ILC.
  • Change in surgical management (e.g., conversion to mastectomy).

Exploratory objectives: 1) To correlate 18F-FES standardized uptake value of SUVmax with immunohistochemical quantification of ER expression and ILC cellularity. 2) To define an 18F-FES SUVmax threshold for pathology-confirmed ER-positive ILC.

Study Type

Interventional

Enrollment (Estimated)

30

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

    • Wisconsin
      • Madison, Wisconsin, United States, 53792
        • UW Carbone Cancer Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Female

Description

Inclusion Criteria:

  • Adults assigned female sex at birth
  • Newly diagnosed ILC confirmed on core-needle biopsy (greater than or equal to 1 percent ER staining per American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) guidelines)
  • have undergone or will undergo standard-of-care (SOC) clinical and imaging assessments (e.g., mammography, ultrasound, breast MRI)
  • planning for mastectomy or breast-conserving surgery within 12 months of their initial diagnosis
  • Provision of signed and dated informed consent form

Exclusion Criteria:

  • Patients with history of ipsilateral axillary lymph node dissection

  • Patients who received anti-estrogen therapy such as selective estrogen receptor degrader (SERD, e.g., fulvestrant, elacestrant) in the last 28 weeks or selective estrogen receptor modulator (SERM, e.g., tamoxifen, raloxifene) in the last 8 weeks.

  • Pregnancy or breastfeeding

  • Patients with known allergic or hypersensitivity reactions to previously administered GBCAs or related drug.

  • Patients with a contraindication to MRI, or who cannot be positioned within the scanner because their body weight or diameter exceeds the scanner limits.

  • Patients requiring intravenous (IV) conscious sedation for imaging are not eligible; patients requiring mild, oral anxiolytics for the clinical MRI will be allowed to participate as long as the following criteria are met:

    1. The subject has their own prescription for the medication
    2. The informed consent process is conducted prior to the self-administration of this medication
    3. They come to the research visit with a driver
  • Concurrent participation in another clinical study that, in the judgment of the PI, would interfere with study procedures, endpoint assessment, interpretation of imaging findings, or participant safety.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Participants with Lobular Breast Cancer

Participants will undergo FES PET/MRI imaging after SOC imaging, followed by SOC breast surgery / biopsy

  • Dose: Approximately 6 millicuries (mCi) (222 megabecquerels (MBq)) ± 20%
  • Administration: IV injection, contralateral to the primary tumor site
  • Physical Half-life: ~110 minutes
  • Mechanism: FES binds to estrogen receptors expressed on tumor cells, enabling visualization of ER-positive disease sites.
Other Names:
  • Cerianna
  • Fluoroestradiol
  • 18F-FES
  • PET radiopharmaceutical

Participant undergoes PET/MRI scan to image ER-positive disease sites

Other Names:
  • magnetic resonance imaging
  • PET/MRI

Administered during the MRI portion of the examination

Other Names:
  • GBCA

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percent of Participants where Disease is Detected using 18F-FES-PET/MRI
Time Frame: up to 6 months

The number of participants for which disease is detected using 18F-FES-PET/MRI compared to the number of samples identified with disease (histopathology) will be reported to estimate the sensitivity of 18F-FES-PET/MRI for detecting disease that is occult (hidden) on SOC imaging.

up to 6 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Participant Level Positive Predictive Value (PPV)
Time Frame: up to 6 months

Defined by histopathology as the reference standard. This is the odds of 18F-FES-PET/MRI imaging predicting disease.

up to 6 months
Proportion of Participants Upstaged using a composite of the T, N, and M stages
Time Frame: up to 6 months

A cancer is staged by describing the: the size of the Tumor, whether the cancer has spread to lymph Nodes, and whether the cancer has spread to other organs, or Metastasized (TNM staging). TNM upstaging is when a patient is discovered to have more advanced cancer than initially imaging.

up to 6 months
Proportion of patients who are diagnosed with pathology-proven multifocal, multicentric or contralateral disease
Time Frame: up to 6 months

The proportion of patients who are diagnosed with pathology-proven multifocal, multicentric or contralateral disease will be measured to characterize the frequency of the detection of extensive breast involvement by 18F-FES-PET/MRI.

up to 6 months
Percent of participants where 18F-FES-PET/MRI changed clinical care compared to SOC image
Time Frame: up to 6 months

The following will be reviewed: frequency of changes in treatment intent from curative to palliative after detecting occult metastatic disease; conversion to neoadjuvant therapy after detecting occult locally advanced disease; and changes in axillary surgery from sentinel lymph node biopsy to targeted axillary dissection or complete axillary lymph node dissection after detecting occult axillary metastases in order to characterize the clinical impact of 18F-FES-PET/MRI on treatment decision.

up to 6 months
Lesion-level agreement of the maximal tumor dimension
Time Frame: up to 6 months

The lesion-level agreement of the maximal tumor dimension for the indexed ILC lesion, comparing imaging measurements with pathology measurements among patients who underwent definitive surgery will be reported to characterize the agreement of ILC tumor size between imaging exams (18F FES PET-MRI and SOC breast MRI, ultrasound and mammogram) and histopathologic exams.

up to 6 months
Lesion-level error rate in maximal tumor dimension
Time Frame: up to 6 months

The lesion-level error rate in maximal tumor dimension using pre-specified relative threshold of less than or equal to 25 percent difference between imaging and pathology measurements will be reported to characterize the error rate in size measurements between radiology and pathology for primary ILC.

up to 6 months
Percent of participants where 18F-FES-PET/MRI changed surgical planning
Time Frame: up to 6 months

The frequency of changed surgical planning (conversion from planned lumpectomy to mastectomy due to extensive breast involvement; margin re-excision in those undergoing lumpectomy; conversion to mastectomy in those initially managed with lumpectomy) will be reported to characterize the clinical impact of 18F-FES-PET/MRI on surgical planning.

up to 6 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Collaborators

Investigators

  • Principal Investigator: Wenhui Zhou, MD, PhD, UW School of Medicine and Public Health

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

November 1, 2026

Primary Completion (Estimated)

November 1, 2028

Study Completion (Estimated)

November 1, 2028

Study Registration Dates

First Submitted

October 26, 2026

First Submitted That Met QC Criteria

October 26, 2026

First Posted (Actual)

November 2, 2026

Study Record Updates

Last Update Posted (Actual)

November 3, 2026

Last Update Submitted That Met QC Criteria

October 30, 2026

Last Verified

October 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • 2026-1072
  • SMPH | Radiology (Other Identifier: UW Madison)
  • Protocol Version 8/14/26 (Other Identifier: UW Madison)
  • UW26018 (Other Identifier: OnCore ID)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.