|How opto-acoustic technology works--Courtesy of Seno Medical (click to enlarge)|
Seno Medical hopes that its opto-acoustic breast cancer screener will be used to make it easier for physicians to identify benign masses than traditional ultrasound methods alone. In practice, this could help limit the need for biopsy to determine cancerous masses.
Later this year, the San Antonio, TX-based startup is slated to have data from its U.S. pivotal PIONEER study in more than 2,100 patients, which is an expansion upon this pilot data. That study is intended to support a PMA application for Seno's Imagio breast imaging system.
The pilot study was in 102 masses that were evaluated with Imagio opto-acoustic images; traditional ultrasound images were taken prior to that OA exam and used later as a control. Using the Imagio system, 75 of the masses were biopsied, with 39 found to be benign and 36 malignant.
The startup's system allowed the 7 radiologists in the study to downgrade several masses that might otherwise have required biopsies, without raising the risk of missing cancer. In the pilot data, Imagio's OA imaging had 97.6% sensitivity (how often a positive test is accurate) and 44.4% specificity (how well a negative result rules out disease).
|Dr. Erin Neuschler|
"Downgrading benign masses classified as BR 4b (moderate suspicion), 4a (low suspicion) and 3 without missing cancers is an unmet need that the Imagio OA breast imaging system can potentially help address," said Dr. Erin Neuschler, Northwestern Medicine Radiologist and Assistant Professor of Radiology at the Northwestern University Feinberg School of Medicine and the co-principal investigator of the larger pivotal study, in a statement.
She continued, "If these pilot findings are verified after the completion of the multicenter PIONEER Study, we will have confirmation that the Imagio OA breast imaging system could help women not only avoid biopsy procedures but also multiple short interval follow-up ultrasound exams over two years."
The Imagio OA system is designed to identify two aspects of cancer: the presence of abnormal blood vessels (tumor angiogenesis) and the relative reduction in oxygen content of blood that occurs in cancer but not benign masses and other normal tissues.
The system doesn't require the use of contrast agents or any exposure to radiation or radioisotopes, as is the case with other commonly used types of breast cancer imaging. It works by illuminating the breast with laser light of specific wave lengths. Tumors absorb the light and become slightly heated, causing them to expand and emit a pressure wave that is then detected by sensors positioned on the outside of the breast within a probe. These signals are analyzed and assembled into high-contrast, high-resolution color images that represent blood volume and oxygenation status, which are correlated with benign or malignant histopathology.
In 2015, an anticipated almost 232,000 women will be diagnosed with invasive breast cancer in the U.S., with another roughly 60,000 diagnosed with noninvasive breast cancer, according to the American Cancer Society. An additional more than 40,000 U.S. women will die this year of breast cancer.
"Diagnostic specificity remains disappointingly low for diagnostic morphologic imaging modalities and reading algorithms that have been optimized to achieve very high sensitivity at the expense of low specificity--which, of course, results in many false positives and generates a high percentage of negative biopsies," said Seno Medical Director Dr. Thomas Stavros.
"These encouraging results indicate that Imagio can potentially offer physicians a tool to more accurately identify women who do not have breast cancer, and thus, who do not need to undergo invasive and expensive biopsy procedures and/or the stress of undergoing multiple follow-up exams over a two year period," he continued. "As breast radiologists, we can and we should do better in diminishing false positives and reducing negative biopsies. OA is a functional and morphologic diagnostic tool that has the potential to help us achieve better specificity without sacrificing sensitivity, diminish the percentage of negative biopsies generated by breast cancer screening, and to reduce the perceived 'harms' of breast cancer screening."
- here is the announcement