Optical mammography identifies and monitors breast cancer
A new optical imaging technology could give doctors new ways to both identify breast cancer and to monitor the responses of individual patients to initial treatments of the disease. Tufts Medical Center in Boston is now undertaking a five-year clinical study of the procedure through a $3.5 million grant from the National Institutes of Health.
This noninvasive technology uses near-infrared (NIR) light to scan breast tissue, and then an algorithm is applied to interpret the information. The primary structures in breast tissue, which are water, fats, and oxygen-rich and oxygen-poor tissue, can be identified through differences in light absorption.
The NIR technique does not use ionizing radiation, so it can be applied multiple times over a short period without risk of radiation exposure. Unlike other breast imaging methods, it also offers the advantage of obtaining functional real-time images of metabolic changes, such as levels of hemoglobin concentration and oxygenation.
“It's been reported that patients who respond to breast cancer chemotherapy show a decrease in hemoglobin and water concentration and an increase in lipid concentration at the cancer site,” explains Professor of Biomedical Engineering Sergio Fantini, PhD, who is leading the research effort. “This suggests that NIR imaging can be valuable not only in diagnosing breast cancer but in monitoring individual response to therapies without requiring repeated x-rays. For example, it could help determine if a patient is responding to neoadjuvant chemotherapy administered to shrink a tumor before surgery.”
Additionally, optical mammography is more comfortable than traditional mammograms. The technique lightly compresses the patient's breasts between two horizontal glass panels and illuminates them with NIR light. Real-time images of the breasts are displayed by a specialized software program as the optical system scans back and forth. The intensity of the NIR beam as it is transmitted through the breast is displayed by a light detector within the system. The intensity of the transmitted light generates breast images through an algorithm based on the optical information, and the images can be read soon after the procedure.The clinical testing by Fantini and his team is in collaboration with Roger Graham, MD, director of Tufts Medical Center's Breast Health Center and with Marc Homer, MD, chief of mammography at Tufts Medical Center. The NIH-funded study will investigate healthy women, women with breast cancer, and women with benign breast lesions. The effort will seek to examine the effectiveness of optical mammography in detecting breast cancer and in distinguishing between malignant and benign tumors. Also, the study will characterize the power of optical mammography to determine patient response at the beginning of therapeutic treatment by looking at breast cancer patients who are undergoing chemotherapy.