Despite the many advantages that have been gained in the past years with mammography, it is estimated that 20 percent or more breast cancers are still being missed on digital mammograms. One reason for this is that cancers can be hidden by the normal tissues of the breast. Like a tree in the forest, the tissue in front of and behind a cancer can hide cancers on standard 2D digital mammography, limiting the radiologists’ ability to detect them. In addition, normal tissues that are actually in different parts of the breast may superimpose one on top of the other creating the false impression of a possible cancer when none is present. This leads to women being recalled from screening for additional views to sort things out while creating inconvenience and anxiety.
Digital Breast Tomosynthesis (DBT) is a technology that helps to reduce these problems. Invented at the Massachusetts General Hospital in Boston by one of the World’s leading experts in breast cancer detection and diagnosis, and developed in partnership with GE, SenoClaire* is a new DBT solution that received FDA approval last week. SenoClaire utilizes low dose mammograms taken from different directions and uses powerful computing to produce multiple images like the pages in a book that look like cuts through the breast so that each plane is virtually free of overlapping tissue in front and behind. This results in sharply rendered views of each plane while structures in the other planes in front and behind disappear. The technology can then reconstruct a representation of the entire breast by combining the set of virtual cuts. Tomosynthesis, which is already in use in imaging solutions such as CT scans and MRIs, is a way to get the three-dimensional information that doctors need.
“Our technology provides extremely clear images” explains Remy Klausz, Principal Engineer, Detection and Guidance Solutions, GE Healthcare. “One way of performing DBT would be to have the x-ray tube move continuously taking pictures while in motion. Imagine taking a picture with a camera inside a fast moving car,” he adds “The pictures would likely turn out blurry. To avoid that blur and capture sharper images, it’s best to stop the car to take the picture. SenoClaire uses a comparable method called ‘step and shoot’, which eliminates this type of blurring. It’s different from other 3D tomosynthesis technology, which can result in blurring. Importantly, SenoClaire delivers this exceptional3D image but at the same low-dose radiation level as standard 2D technology.”
SenoClaire is indicated for the acquisition of 2D images and also for the acquisition of multiple projection views intended to produce 3D DBT images suitable for screening and diagnosis of breast cancer. SenoClaire can be used for the same clinical applications as traditional mammography for screening mammography.
A screening examination will consist of:
• A 2D image set consisting of a craniocaudal view and of a mediolateral oblique
• A 2D craniocaudal view and 3D mediolateral oblique image set.
GE researched and developed step-and-shoot digital breast tomosynthesis over the last decade. “This is a key milestone in our mission of providing women with cutting edge screening technology to detect early breast cancer,” said Dr. Daniel Kopans, Senior Radiologist, Breast Imaging Division Department of Radiology, Massachusetts General Hospital. “When cancer is identified and treated earlier, lives can be saved.”
In the step-and-shoot method, after each image is taken, the movement resumes and the x-ray source moves to the next position. The average acquisition takes less than 10 seconds. This approach heightens image clarity and is made possible because of the technology’s light-weight and sophisticated steady rotating tube-arm.
Tiny calcifications can often be the only indicator of breast cancer. “Some devices have to prioritize the speed at which an image is acquired, due to the continuous sweep they employ,” said Klausz. “And a simple way to increase speed is to reduce the number of pixels, thereby reducing image quality. But GE’s step-and-shoot mode makes this pixel reduction unnecessary, thereby allowing a strong visualization of small objects, such as microcalcifications.” In a study from the Massachusetts General Hospital, it was found that microcalcifications were more clearly depicted on GE’s DBT system with greater clarity than with 2D digital mammography.¹
SenoClaire is a prescription medical device that is limited to sale, distribution, or use, to or on the order of a physician. Medical device imaging is not without risk, please discuss the risks associated with mammography with your healthcare professional.
*Trademark of General Electric Company
Learn more about GE’s $1 billion R&D commitment to cancer diagnosis technologies at http://www.getacklingcancer.com/
¹ Kopans DB, Gavenonis S, Halpern E, Moore RH. Calcifications in the Breast and Digital Breast Tomosynthesis The Breast Journal 2011;17:638–644