Deborah J. Rhodes, M.D., studies the application of a new breast imaging device, molecular breast imaging, to breast cancer screening. The long-term goal of Dr. Rhodes' research is to develop an individualized approach to breast cancer screening that incorporates breast density, age, and other factors that impact breast cancer risk and mammography sensitivity.
The goal of an individualized approach to screening is to improve breast cancer detection while minimizing both the cost of screening and the harms associated with false-positive results and overdiagnosis.
- Molecular breast imaging (MBI). Over the last 10 years, Dr. Rhodes has worked with a multidisciplinary team at Mayo Clinic (representing radiology, internal medicine, surgery, nuclear physics and biomedical engineering) led by Michael K. O'Connor, Ph.D., to develop MBI. This nuclear medicine-based breast imaging technique utilizes small high-resolution gamma camera detectors in a dual-detector configuration that permits the breast to be imaged in a comparable manner to mammography but uses light, pain-free compression (fewer than 15 pounds of force).
MBI involves injection of a radiotracer that is preferentially absorbed by rapidly proliferating cancer cells. Thus, MBI can distinguish tumors from background dense breast tissue, which can have the same appearance on a mammogram. In the team's clinical trial comparing mammography with MBI in more than 2,600 women with dense breasts, they have demonstrated that MBI detects an additional 10 cancers per 1,000 women screened relative to mammography screening alone.
- Breast density. Breast density is the single most important factor in the failure of mammography to detect breast cancer. Dr. Rhodes' team studies the impact of breast density on screening modalities.
They are also studying the implications of benign patterns of MBI radiotracer uptake on breast cancer risk by analyzing the differences in cellular composition between benign breast tissue that appears dense on mammogram but has minimal radiotracer uptake on MBI versus tissue that appears dense on a mammogram but has avid radiotracer uptake on MBI. She and her team believe that the pattern of radiotracer uptake on MBI may mirror the degree of cellular proliferation in the breast, which in turn may provide a tool to predict individual risk of developing breast cancer.
Significance to patient care
Recent large patient trials from Mayo Clinic indicate that MBI improves the detection of breast cancer in women with dense breasts relative to mammography alone. MBI has advantages that make it well-suited as an adjunctive screening technique for women with dense breasts, including favorable cost, ease of interpretation and a low rate of false-positive findings.