Evaluation Background: Mammography Systems with Tomosynthesis
March 11, 2020 | Evaluations & Guidance
Here's background for our Evaluations of mammography systems with tomosynthesis, outlining the key considerations for making wise purchasing decisions. Learn about the technology, which specs are important, and what factors we test for. Also review our product ratings, typical costs of ownership, and ECRI's data describing hospitals' interest in each vendor.
Tomosynthesis provides a series of 2-D images through the breast for screening or diagnosis of breast cancer. Mammography systems with tomosynthesis are equipped to move the x-ray tube in an arc around the breast to acquire multiple projection images. A series of thin breast slices are reconstructed from these projections; this process is known as digital tomosynthesis. The thin slices reduce the chance that overlying breast tissue will obscure a lesion or other finding.
Digital breast tomosynthesis (DBT) mammography has been under development since the introduction of digital mammography in the early 2000s. The first commercial DBT system in the United States obtained regulatory approval (premarket approval) from FDA in 2011, as ECRI reported in Breast Tomosynthesis: 3-D Mammography Reaches the U.S. Market.
It is recognized that digital mammography does not detect all breast cancers. One reason for this is that lesions are sometimes obscured by overlying normal breast tissue.
Another issue affecting digital mammography is that a substantial number of patients are recalled due to radiologists not being certain of their findings. About 10% of patients are recalled following a screening study for additional imaging. Of the patients recalled, about 5% are expected to have breast cancer. Recalling a patient increases both the patient's anxiety and the costs.
DBT was developed to address these issues. It was expected that DBT would both increase breast cancer detection and reduce recall rates. Although initial data was not sufficient to prove this, several clinical studies have now been published showing that both higher detection rates and lower recall rates can be achieved. However, controversies remain related to the appropriateness of the design of those studies.
In addition to questions about the clinical efficacy, there is debate over the optimum number of images to acquire. Higher image quality is achieved by acquiring...