3D mammography improves cancer detection

By Dr. Walter Silbert
Cayuga Medical Center

A new generation of mammogram technology at Cayuga Medical Center is providing a more sensitive and clinically proven breast cancer exam that facilitates earlier cancer detection and reduces callbacks for additional diagnostic testing. The technology called 3D mammography, or digital breast tomosynthesis, is now available at Cayuga Medical Center’s main campus, East Campus and Cortland outpatient offices. Schuyler Hospital expects to offer the improved testing in May.

Cayuga Medical Center installed the new Hologic Selenia Dimensions Digital Breast Tomosynthesis units earlier this year after the FDA approved the equipment in mid 2017. Multiple studies since 2011 have shown the improved technology provides several important benefits for women:

  • Earlier detection of small breast cancers that may be hidden on a conventional mammogram.
  • Clearer images of abnormalities within dense breast tissue.
  • Greater accuracy in pinpointing the size, shape and location of breast abnormalities.
  • Improved detection of multiple breast tumors.
  • A reduction of up to 40 percent in callbacks for additional testing.

About 40 percent of women ages 40 to 74 have dense breasts. That can make conventional, 2D digital mammogram images difficult to evaluate and often requires additional tests that can result in increased patient anxiety and unnecessary costs. The new units at Cayuga Medical Center combine 2D digital mammography with 3D mammography in a single test to provide more imaging information to radiologists reviewing the images. In addition to improving the accuracy of the diagnosis, the combined 2D and 3D imaging is done without exposing patients to the additional radiation that would be required if separate tests were done.

What is 3D mammography?

The technology uses a low-dose x-ray system and computer reconstructions to create three-dimensional images of the breasts.

In contrast, a conventional mammogram is two-dimensional: two x-ray images are taken of the breast, from top-to-bottom and from angled side-to-side, while the breast is compressed between a paddle and an imaging detector. Although compression is necessary to obtain breast images, it may cause overlapping of the breast tissue in which abnormal tissue can be hidden and superimposed normal tissue can appear abnormal.

In 3D mammography, the x-ray tube moves in an arc over the compressed breast capturing multiple images of each breast from different angles. These digital images are then reconstructed or “synthesized” into a set of three-dimensional images by a computer. These images minimize the tissue overlap that can hide cancers or make it difficult to distinguish normal overlapping breast tissue from tumors.

How does the procedure work?

Multiple low-dose x-ray images of the breast are digitized and then transferred to a computer where they are reconstructed into a three-dimensional image set. In this way, 3-D breast imaging is similar to computed tomography (CT) imaging in which a series of thin high-resolution “slices” are assembled together to create a 3-D reconstruction of the body. Numerous studies have shown 3D mammography is 20 to 60 percent more accurate in detecting invasive breast cancer when compared to 2D mammography alone. Invasive cancers are the types of cancer that may advance to become life threatening if not detected in time for effective treatment.

What happens in the procedure?

The new Hologic Selenia units look similar to conventional, 2D mammography units. The top of the Hologic machine has an arm that contains a tube that produces the x-rays. During the imaging, the arm moves in an arc of about 15 degrees to the right and left to obtain low dose images at multiple angles. The unit is used exclusively for x-ray exams of the breast, and special shielding assures that only the breast is exposed to the x-rays.

As with conventional mammograms, adequate compression of the breast is necessary to obtain the highest quality mammogram. Some women with sensitive breasts may experience discomfort during the procedure. If discomfort is significant be sure to inform the technologist and less compression will be used.

How long does the test take?

The test takes about 60 seconds. When the scan is completed, a radiologist reviews the images and in most cases your results are available before you leave the office or at the latest by telephone within one business day. The rapid turnaround allows for any further diagnostic testing, if needed, to be performed at the same time or within a few days.

Dr. Silbert is board certified in diagnostic radiology and is on the medical staff of Cayuga Medical Center. To schedule a 3D mammogram, call 607-274-4227.