The National Institutes of Health (NIHS) has awarded Tufts Medical Center in Boston a $3.5 million grant to conduct a five-year clinical study of optical mammography.
Optical imaging technology, which was developed at Tufts University School of Engineering, could provide physicians new ways to identify breast cancer and monitor individual patients' response to initial treatment of the disease.
The non-invasive technology uses near infrared (NIR) light to scan breast tissue, and then applies an algorithm to interpret that information. Differences in light absorption allow identification of water, fats, and oxygen-rich and oxygen-poor tissue.
The NIR technique could complement standard mammography, particularly for women younger than 40 years old who may have dense breast tissue that tends to obscure detail in x-rays, according to Tufts.
The NIR technique does not use ionizing radiation, and can be applied multiple times over a short period without risk of radiation exposure, Sergio Fantini, PhD, professor of biomedical engineering at Tufts, said in a press release. Another potential for the technology is that it can obtain 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," Fantini explained. "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."
During an optical mammogram, the patient's breasts are lightly compressed between two horizontal glass panels and then illuminated by NIR light. A software program displays real-time images of the breast as the optical system scans back and forth. A light detector within the system displays the intensity of the NIR beam as it is transmitted through the breast.
By using an algorithm based on the optical information, the technology generates breast images using the intensity of the transmitted light. The images can be read soon after the procedure. The technology can be packaged into portable, handheld devices.
Proof of concept
In collaboration with Roger A. Graham, MD, director of Tufts Medical Center's Breast Health Center, and Marc J. Homer, MD, chief of mammography at Tufts, Fantini and his team conducted proof-of-concept tests to see if their procedure could corroborate information gathered with x-rays on two patients who each had suspicious lesions in one of their breasts.
The optical imaging was successful in enabling the team to identify cancerous tissue. "The test results were compatible with what we found in the x-ray mammography," Graham said in a release. "It was also painless for the patients and eliminated radiation exposure."
The NIH-funded study will investigate healthy women, women with breast cancer and women with benign breast lesions in an effort to examine the effectiveness of optical mammography in detecting breast cancer and distinguishing between malignant and benign tumors. The study also will look at breast cancer patients who are undergoing chemotherapy to characterize the power of optical mammography to determine patient response at the beginning of therapeutic treatment.