By: Lisa Chamoff
Researchers at Washington University in St. Louis predict a new breast imaging modality that combines ultrasound and near-infrared imaging, or diffuse light tomography, can reduce unnecessary biopsies by up to 45 percent.
The team — Quing Zhu, professor of biomedical engineering at the Washington University in St. Louis School of Engineering & Applied Science and of radiology in the School of Medicine, and Dr. Steven Poplack, the Ronald and Hanna Evens Endowed Chair in Women’s Health at Barnes-Jewish Hospital, professor of radiology at the Mallinckrodt Institute of Radiology at Washington University and breast radiologist at the Siteman Cancer Center — was awarded $2 million from the National Cancer Institute at the National Institutes of Health (NIH) to investigate the technique, which uses ultrasound-guided diffuse light tomography.
The imaging method, developed by Zhu starting in 2003, uses a prototype of a commercial ultrasound transducer within a near-infrared optical imaging sensor array. Using the ultrasound, clinicians find the mass and then perform the near-infrared light scan. Near-infrared light is absorbed by hemoglobin, which is found in higher concentrations in in breast cancer than benign tumors.
Zhu and coworkers recently performed a retrospective study of 288 patients, looking at the hemoglobin in their breast tumors, and found that the technique would have reduced the number of benign biopsy referrals by 45 percent.
“If we can save 45 percent of benign biopsies, that is a large savings in healthcare costs,” Zhu told HCB News.
A clinical trial of 300 patients at the Joanne Knight Breast Health Center at Siteman Cancer Center is planned.
Patients with abnormalities visible on ultrasound that are sent for biopsy will also undergo a diffuse light tomography scan. Radiologists will decide how suspicious the tumor is based on conventional imaging (with ultrasound and mammography), and then see if that level of suspicion changes due to information from the light scan.
A smaller group will also have a contrast-enhanced mammogram, an emerging technology that also identifies abnormalities based on blood content. Investigators will compare the results of the light scan to that of the contrast enhanced mammogram.
“We think there will be a significant proportion where the optical images will say this is very likely not to be cancer,” Poplack told HCB News. “Of all patients sent for ultrasound-guided biopsy, 65 to 85 percent turn out to be benign.”
The team hopes to have preliminary results in a couple of years.
The goal is to reduce benign biopsies while not missing any cancers. Zhu said the technology is also useful for monitoring breast cancer patients’ response to neoadjuvant chemotherapy .
“The clinical trial will bring the technology further attention to the industry and I think it will be an important step toward commercialization,” Zhu said.
Clinical use of the technology would require further trials with more patients, but the early results are promising.
“Diffuse light tomography does not have ionizing radiation, doesn’t involve compression, is relatively inexpensive and it’s portable,” Poplack said. “Given all of those features if we can demonstrate it really has utility distinguishing benign from malignant masses, as an adjunct, it certainly has a lot of potential for clinical application.”
Barbara Jacoby is an award winning blogger that has contributed her writings to multiple online publications that have touched readers worldwide.