Seno Medical Instruments, the company pioneering the development of an opto-acoustic (OA) device as a new tool to improve the process of diagnosing breast cancer, announced results of its Pilot Study portion of the PIONEER pivotal study.
The pilot study demonstrated the potential of the company’s Imagio breast imaging system to improve physicians’ ability to accurately classify benign breast masses compared to traditional ultrasound methods.
The results of the 100 subject pilot study, conducted as the initial part of a larger U.S.-based, multicenter PIONEER pivotal study of over 2,000 subjects, were presented at the annual meeting of the Radiological Society of North America (RSNA) on December 2 in Chicago, IL.
The PIONEER study is being conducted to demonstrate the ability of the Imagio OA breast imaging system to downgrade BI-RADS® (Breast Imaging-Reporting and Data System) scores. Specifically, whether masses originally scored BI-RADS (BR) 4a or 4b (in which a suspicious abnormality is discovered and a biopsy is recommended) could be downgraded to either BR 3 (probably benign, <2% likelihood of malignancy with short-interval follow-up recommended) or 2 (benign) and if masses coded BR 3 could be downgraded to 2.
Seven independent breast radiologist readers (IRs) and an expert radiologist (ER) trainer blindly assessed 102 masses from the pilot study cases using only Imagio OA images. Among these subjects, there were 75 biopsied masses (39 benign, 36 malignant). Gray-scale ultrasound images were taken with the Imagio system’s conventional ultrasound immediately prior to the OA exam. These images were designated the internal ultrasound control (IUC). Later, the IRs assigned a BR score to these images.
Using OA, the IRs downgraded conventional diagnostic ultrasound findings classified BR 3 masses to BR 2 in 33% of cases, BR 4a masses to BR 2 or 3 in 53% of cases, and BR 4b masses to BR 3 or 2 in 33% of cases. Using OA, the IRs downgraded BI-RADS categories of the internal ultrasound control-classified BR 3 masses to BR 2 in 43% of cases, BR 4a to either BR 3 or 2 in 43% of cases and BR 4b masses to either BR 3 or 2 in 13% of cases. OA had 97.6% sensitivity and 44.4% specificity.
The Imagio OA breast imaging system was designed to identify the two functional hallmarks of cancer: the presence of abnormal blood vessels (tumor angiogenesis) and the relative reduction in oxygen content of blood that occurs in cancer compared to benign masses and normal tissues.
The technology used by the Imagio system is non-invasive and does not require patient exposure to contrast agents, ionizing radiation (x-ray) or radio-isotopes, which are required for other modalities that are capable of functional imaging, including magnetic resonance imaging (MRI) or positron emission tomography (PET).
"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 Thomas Stavros, MD, FACR, FSRU, FRANZCR, Medical Director of Seno Medical Instruments.
The RSNA annual meeting is the premiere conference in the world for radiology and medical imaging leaders. It is an international forum of peer-reviewed research, state-of-the-art technology and education for radiologists, radiation oncologists, medical physicists and allied scientists.