The US Food and Drug Administration (FDA) has approved an ultrasound device shown to be capable of detecting small masses in dense breasts. The device, the somo-v Automated Breast Ultrasound System (ABUS), is indicated for use in combination with mammography for breast cancer screening.
“A physician may recommend additional screening using ultrasound, for women with dense breast tissue and a negative mammogram,” said Alberto Gutierrez, PhD, director of the office of in vitro diagnostic device evaluation and safety at the FDA’s Center for Devices and Radiological Health, in a press release. “The somo-v ABUS is a safe and effective breast ultrasound tool when such screening is recommended.”
The study that led to the approval involved the asymptomatic cases of 200 women with dense breasts from a prospective multicenter registry. The patients were screened with both mammography and somo-v ABUS. Board-certified radiologists reviewed either mammography alone or with the somo-v ABUS images. Biopsies were performed to confirm cases of cancer. The study found that the use of the ultrasound device improved cancer detection with an area under the curve of 0.75 compared with 0.60 for mammography alone, a 24% increase over mammography alone (P < .001).
Using somo-v ABUS in addition to mammography improved the true positive rate by 30%; the rate of false positives was increased by 4%.
Dense breasts have a high amount of fibroglandular tissue compared to less-dense breasts (which have a high amount of fatty tissue), and are associated with an increased risk of breast cancer. On mammograms of dense breasts, both breast tumors and fibroglandular tissue appear as solid white areas on mammograms, obscuring smaller tumors. Detection usually occurs at a more advanced stage of disease.
About 40% of women who undergo screening have dense breasts, according to estimates from the National Cancer Institute.
In ultrasound imaging, which can detect small masses in dense breast, a transducer directs high-frequency sounds waves toward the area of the body being evaluated. The specially shaped transducer of the somo-v ABUS can scan an entire breast in about a minute, producing several images for review.
Prior surgery, or procedures such as a biopsy, can alter the appearance of breast tissue in an ultrasound image. The the somo-v ABUS is therefore approved for use in patients who have not had previous clinical breast intervention.
The FDA has required that U-Systems Inc, the manufacturer of the somo-v ABUS, train physicians and technologists who will use the new device.