Breast tomosynthesis - a tool for early detection of breast cancer
Breast cancer is the second most common cancer worldwide among women whose first line of screening is mammography. While being a preliminary diagnostic tool, mammography can yield overlapped tissue images and cause inaccurate interpretation of results.
Digital Breast Tomosynthesis (DBT) is slowly replacing conventional mammography, solving the problem of tissue overlap. Also referred to as three-dimensional (3D) mammography, DBT reconstructs a 3D image of the breast from multiple images taken using a low-dose X-ray system.
Writing, in the Journal of the American Medical Association, Elizabeth A. Rafferty stated that DBT helps in explicit diagnosis of more invasive breast cancers, improves detection rates, and reduces unnecessary callbacks. Early detection of breast cancer allows more treatment options, and so can increase a woman’s chances of survival.
In a conventional mammogram, fibro glandular and fatty breast tissues appear white and grey in colour respectively. Any abnormalities such as tumors also appear white. This makes differentiating a normal breast tissue and tumor difficult, especially in women with dense fibro glandular tissues. A potentially cancerous tumor can escape detection in a mammogram if it is overlapped by breast tissues. On the other hand, DBT presents the dense tissue of breast explicitly by taking multiple images of breast similar to that of a CT scan. The X-ray tube in DBT moves in an arc over the breast, capturing images of its each anatomical layer. As a result, the overlap is removed and tumors are much easier to recognise. While this increases the report reading time by about 50%, compared to a 2D mammography, DBT’s improved tissue identification, tumor visualisation, and a lower recall rate for additional testing make it the foremost test for screening breast cancer.
While this breakthrough technology has been available in Europe and other countries since 2008, it was first launched in the US with US Food and Drug Administration (FDA) approval by Hologic in 2011 under the name Selenia Dimensions. This played a major role in increasing annual revenues of breast health products for Hologic by 5.1% in 2016. Later on, companies such as GE Healthcare and Siemens entered the market taking DBT to more than 50 countries.
According to GlobalData estimates, the global breast tomosynthesis market was valued at $0.62bn in 2016 and is forecast to be worth $1.12bn by 2020. There is expected growth in investments in breast cancer related research by various governmental and non-governmental organisations, as well as better awareness and increased efforts to detect cancer in early stages. These are the key factors driving the growth of the breast tomosynthesis market. On the other hand, the market needs to overcome restraining forces such as high installation cost of the device and side effects of high frequency radiation exposure.