This prospective, one-arm study which will enroll participants with biopsy-proven DCIS scheduled for diagnostic breast MRI for preoperative staging/extent of disease evaluation as part of standard of care. Eligible participants will be consented for participation in the research study which includes a directed breast PET/MRI with 18F-FES. 18F-FES uptake of the known malignancy will be measured on the PET/MRI examination using standardized uptake values (SUV) and tumor-to-normal tissue ratios.

Integrated whole-body magnetic resonance imaging (MRI)-positron emission tomography (PET) scanners have recently been introduced for clinical use. This technology combines the anatomic and perfusion data obtained with Dynamic Contrast Enhanced (DCE) MRI with functional imaging data obtained from PET. For breast imaging, the combination of MRI and PET has important potential to improve diagnostic accuracy and provide molecular characterization of breast cancer. The overall purpose of this research is to determine the technical feasibility of simultaneous breast DCE MRI with 18F-FES PET for measuring estrogen receptor (ER) in patients with ductal carcinoma in situ (DCIS) and identifying patients with low-risk of disease recurrence. The hypothesis is that quantitative 18F-FES uptake parameters from PET/MRI will correlate well with the ER immunohistochemistry score and with low-risk recurrence scores.

Primary Objective 1) To compare quantitative 18F-FES uptake of biopsy-proven DCIS measured using PET/MRI with ER protein levels determined by immunohistochemistry.

Secondary Objectives

1. To determine the optimal cut-point 18F-FES uptake value for distinguishing between ER+ and ER-negative DCIS
2. To determine the test-retest reproducibility of quantitative assessment of tumor 18F-FES uptake
3. To determine the optimal cut-point 18F-FES uptake value for distinguishing between low-risk DCIS and intermediate/high-risk DCIS
4. To estimate the association of quantitative 18F-FES uptake (continuous SUVmax) with research-based Oncotype DX DCIS scores (0-100)
5. To measure the upgrade rate to invasive cancer at surgical excision
6. To correlate tumor 18F-FES uptake with serum estradiol and sex hormone binding globulin levels.

Exploratory Objective

1) To correlate tumor cell density with 18F-FES uptake on PET/MRI

Inclusion Criteria:

• Diagnosis of biopsy-proven DCIS without invasion or microinvasion measuring at least 1.0 cm in diameter by any imaging modality
• Undergoing diagnostic breast MRI ordered by the referring clinician for staging and extent of disease

Exclusion Criteria:

• Inability or unwillingness to provide informed consent to the study

• Surgery, radiation, neoadjuvant chemo/endocrine therapy for the current malignancy prior to study enrollment

• Participants currently taking or have taken an ER-blocking medication (e.g. tamoxifen, raloxifene) within 6 weeks prior to study enrollment

• Pregnant or lactating women

• Participant with intolerance or contraindications for MRI or gadolinium-based contrast agents

• Participant girth exceeds the bore of the MRI/PET scanner

• Participants with a history of allergic reaction attributable to compounds of similar chemical or biologic composition to 18F-FES

• Participants in liver failure as judged by the patient's physician, due to the hepatobiliary clearance of 18F-FES

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

  • The participant has their own prescription for the medication
  • The informed consent process is conducted prior to the self-administration of this medication
  • They come to the research visit with a driver or an alternative plan for transportation (e.g. Uber, taxi, etc.)

up to 24 hours