This study compares molecular breast imaging (MBI) and digital breast tomosynthesis (DBT) in screening patients with dense breast tissue. Breast imaging may help doctors find breast cancer sooner, when it may be easier to treat. Molecular breast imaging (MBI) uses an injection of a small amount of radioactive material that is taken up in tissues of the body that are actively changing, such as breast cancer. A specialized camera, called a gamma camera, takes pictures of the gamma rays emitted by this material. MBI may detect cancers that are not visible on mammograms. This study may help researchers determine how MBI testing compares to DBT screening.

This study includes women age 40-75 who are presenting for breast cancer screening and had mammographically dense breasts on their last mammogram. Participants undergo annual DBT and MBI screening for two years. The primary aim for this study is to compare the rate of detection of invasive cancers between DBT alone vs. the combination of DBT with supplemental MBI at the first year of screening.

Inclusion Criteria:

• Patient is a consenting female age 40-75 years
• Patient is scheduled for routine screening DBT
• Patient is asymptomatic for breast disease
• Patient had heterogeneously dense or extremely dense breasts on most recent prior mammography examination (Breast Imaging Reporting and Data System [BI-RADS] c or d) within 24 months of enrollment
• Patient is able to participate fully in all aspects of the study (completing study visits and study data collection)
• Patient understands and signs the study informed consent
• Patient anticipates being able to return one year after study enrollment to complete the second round of screening

Exclusion Criteria:

• Patient is currently pregnant or plans to become pregnant during the course of the study
• Patient is currently lactating
• Patient has had a prior MBI
• Patient has had a prior whole breast ultrasound (WBUS) for screening, with either a hand-held ultrasound probe or automated system, within 12 months prior to study enrollment
• Patient has had a prior breast MRI
• Patient has had a prior contrast-enhanced mammogram (contrast enhanced spectral mammography [CESM] or contrast-enhanced digital mammography [CEDM])
• Patient is concurrently participating in any other breast imaging research studies that involve undergoing additional breast imaging tests beyond routine screening with mammography, including but not limited to contrast-enhanced mammography, WBUS, MBI, or contrast-enhanced breast MRI
• Patient has had a breast biopsy within 3 months prior to study enrollment
• Patient has had breast surgery within 12 months prior to study enrollment
• Patient is currently undergoing treatment for breast cancer or planning surgery for a high-risk breast lesion (atypical ductal hyperplasia [ADH], atypical lobular hyperplasia [ALH], lobular carcinoma in situ [LCIS], papilloma, radial scar)
• Patient is currently taking a chemoprevention agent for breast cancer risk reduction or osteoporosis prevention (tamoxifen, raloxifene, anastrazole, letrozole, exemestane)
• Patient has a known history of any condition or factor judged by the investigator to preclude participation in the study or which might hinder study adherence

2978 participants met eligibility criteria and had both DBT and MBI screening performed

365 days after screening