New technology from MIT hopes to improve the early detection of breast cancer through the use of an ultrasound device attached to a bra. In a study in Science Advances, the MIT team found that they could detect masses as small as 0.3 cm in diameter, the size of an early-stage tumor, and revealed tumors up to 8 cm in depth.
“We believe the device may be especially useful for detecting interval cancers, those tumors that appear between routine mammograms and that are usually very aggressive,” explains senior author Canan Dagdeviren, an associate professor in MIT’s Media Lab. “But with this technology, which will eventually allow you to do imaging at your home, then you can capture the data every week, every month—even collecting 365 data points in a year—instead of having two data points at least a year or two apart.” Between 20% and 30% of breast cancers are not detected by screening mammography but are diagnosed between screening intervals.
To make the device wearable, the researchers designed a flexible, 3D-printed patch, which has honeycomb-like openings. Using magnets, this patch can be attached to a bra that has openings that allow the ultrasound scanner to contact the skin. The ultrasound scanner fits inside a small tracker that can be moved to six different positions, allowing the entire breast to be imaged. The scanner can also be rotated to take images from different angles and does not require any special expertise to operate. In the new study, the researchers showed that they could obtain ultrasound images with resolution comparable to that of the ultrasound probes used in medical imaging centers.
“We are not reinventing ultrasound. Instead, we are changing the form factor of ultrasonography by eliminating many of the layers which makes traditional ultrasonography very bulky,” Dagdeviren explains. First, the ultrasound crystal beam is much smaller and very thin allowing the technology to be more flexible and stretchable and establish an intimate integration with the soft curvilinear tissue of the breast. Instead of applying manual pressure to the breast tissue via traditional ultrasound, the wearable patch prevents distortion of the breast tissue and the tumor itself for better imaging.
“You can make the images overlay with each other and within a few minutes you can take the entire picture of your breast tissue with no pressure applied on top and with no gel in between,” she adds. To see the ultrasound images, the researchers currently have to connect their scanner to the same kind of ultrasound machine used in imaging centers. However, they are now working on a miniaturized version of the imaging system that would be about the size of a smartphone.
The team collaborated with breast oncologists at Massachusetts General Hospital to see how the technology could distinguish between cysts and malignant tumors. “Because we input so much data into our artificial machine learning algorithm, it allows us to identify whether or not a mass is malignant or benign and we hope to decrease false positives,” Dagdeviren says. She also hopes the technology will make biopsy more effective by avoiding the distortion that usually accompanies traditional ultrasonography. “With this technology, you will be more accurate about where to sample from the targeted region.”
Dagdeviren expects the first adopters of the technology to be women at higher risk for breast cancer, such as those with a family history and low breast density. “Those women have the highest probability to develop the most aggressive phenotype, the interval cancer, between two scans,” she explains. “These women are less likely to survive so we would like to provide a device for frequent screening with profound resolution.” She also forecasts use in women with high breast density for whom mammography is not reliable. Ultimately, she would like this technology to reach women in developing countries who have limited access to hospitals, insurance, and expensive equipment like mammograms.
The team projects the device could be helpful in therapeutic drug monitoring. “Currently, we have 265 breast cancer drug lines on the market and we often do not know which ones to use on a particular patient,” Dagdeviren says. The researchers plan to collaborate with drug companies to see if the device can assess the efficacy of a particular drug. “While the patients are on their medication they should be able to monitor their cyst or tumor and how they’re evolving over time.”
The team is now working on a more portable and more affordable version with the hope of creating a marketed product within four-to-five years.
