Early detection is the key to identifying cancer when it’s more easily treated and curable, especially with breast cancer. For many years, early detection in breast cancer depended on self and clinical breast exams as well as regular mammograms.

But recently, technology has improved and provided healthcare professionals with a more advanced tool for breast cancer detection: breast tomosynthesis.

“Breast tomosynthesis, which is also known as 3D mammography, takes multiple X-ray images of each breast from many angles, creating a layer-by-layer view of the breast tissue,” said Geisinger diagnostic radiologist John Scott Farrell, M.D.

The images from this form of mammography reduce tissue overlap that may hide cancers. They also reduce the chance that overlapping normal tissue in the breast can create a shadow on the mammogram that can look like a tumor.

Breast tomosynthesis is different from a standard mammogram in the same way computerized tomography differs from a standard X-ray – it’s a 3-dimensional perspective that tends to provide doctors with a clearer, more accurate view compared to standard mammograms.

“Mammograms usually consist of two X-rays of each breast from top to bottom and side to side,” Dr. Farrell said. “Breast tomosynthesis machines take multiple pictures of each breast from many angles, with the X-ray tube moving in an arc around the breast.”

3D mammograms are designed to overcome some of the limitations of standard mammograms.

With breast tomosynthesis, the breast is positioned in the same way as a conventional mammogram. Compression of the breast is still necessary to produce the best quality images. Both the time it takes to perform the mammogram and the radiation dose to the patient are not significantly different than a standard mammogram.

Breast tomosynthesis is credited with earlier detection of small cancers that may be hidden during traditional mammograms, as well as improved accuracy in identifying shape, size and location of any abnormalities in the breast.

The increased accuracy of breast tomosynthesis results in fewer “callbacks.”

“At times, patients are called back to the imaging center for additional views and/or a breast ultrasound to evaluate an area of concern on the screening mammogram. Most of the time, these areas are caused by normal breast tissue overlap and not breast cancer. But, the whole process of being called back for additional testing can be very stressful and anxiety-provoking for the patient,” Dr. Farrell said. “Tomosynthesis significantly reduces the need for callbacks since it can tease through the layers of breast tissue in 1 millimeter increments. The level of detail is remarkable.”

3D mammography has been found to improve breast cancer detection in women with breast dense tissue.

“Breast cancer is often the same density as the normal breast tissue surrounding it. This is the challenge of mammography. Since cancerous tissue and normal tissue can be the same density, a cancer can “hide” on a conventional mammogram. But tomosynthesis strips all of the surrounding normal tissue away, making breast cancers more apparent and less likely to be hidden by the surrounding normal tissue,” Dr. Farrell said. “As a result, radiologists can detect small cancers years before they would be detectable on traditional mammograms.”

Researchers have found that 3D mammography used with standard mammograms increases breast cancer detection rates by more than 40 percent.