Recruiting
Phase 4

PET/MRI with 18F-FES

Sponsor:

University of Wisconsin, Madison

Code:

NCT07910474

Conditions

Lobular Breast Carcinoma

Eligibility Criteria

Sex: Female

Age: 18+

Healthy Volunteers: Not accepted

Interventions

18Fluoroestradiol (18F-FES)

MRI

Gadolinium-based contrast agent (GBCA)

Study Details

Brief summary:

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.

Conditions

Lobular Breast Carcinoma

Study ID

NCT07910474

Start date

Nov, 2026

Status verified date

Nov, 2026

Completion date

Nov, 2028

Anticipated

Primary completion date

Nov, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: Female

Age: 18+

Healthy Volunteers: Not accepted

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 Design

Enrollment

30 participants

Anticipated

Intervention Model

Single group

Primary purpose

Diagnostic

Interventions and Outcome Measures

Arms

experimental: Participants with Lobular Breast Cancer

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

Interventions

18Fluoroestradiol (18F-FES)

  • 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.

MRI

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

Gadolinium-based contrast agent (GBCA)

Administered during the MRI portion of the examination

Primary outcome measure

  • Percent of Participants where Disease is Detected using 18F-FES-PET/MRI [ Time Frame: up to 6 months ]

Central Contacts and Locations

Central contacts

Cancer Connect

800-622-8922clinicaltrials@cancer.wisc.edu

Locations

UW Carbone Cancer Center

Recruiting

Madison, Wisconsin, United States, 53792

More Information

Sponsor

University of Wisconsin, Madison

Last update posted

Nov 10, 2026

Last verified

Nov, 2026

Keywords

  • diagnostic
  • imaging
  • 18F-FES
  • invasive lobular cancer

Trial information was received from ClinicalTrials.gov and was last updated on 2026-11-11. This information was provided to ClinicalTrials.gov by University of Wisconsin, Madison on 2026-11-10. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.