Screening mammography has been recommended for American women since the 1980s. Screening mammography applies to women without any breast symptoms, such as breast pain, a breast lump, or nipple discharge. The job of screening mammography is to find breast cancer at its earliest stage, before it can be felt or produce symptoms.
The first screening mammography was performed as analog mammography, where the images had to be processed like pictures from a Polaroid camera. With analog mammography what you saw (developed) is what you got. If the images obtained were not adequate, the mammograms would need to be retaken, and the patient exposed to more radiation. The next stage of mammography was digital mammography. Like photos taken by digital photography, the mammographic images could be altered on a computer screen for easier interpretation. And digital manipulation could be used to spare patients more image acquisition, leading to less radiation.
In 2014, a new type of mammography technique became available. This is referred to as “3-D mammography,” or breast tomosynthesis. This study uses the same type of radiation as is used for a regular mammogram, but the radiation source and the detection screen are rotated around the breast as the pictures are being taken. For regular screening mammograms, the radiation source and the screen detector remain stationary for each of the 2 views. With a standard 2-D screening mammogram, the radiologist has just 2 views of each breast to evaluate. With the 3-D mammogram, there are dozens or as many as 100 images to review. Each image brings into focus a “slice” of the breast tissue, allowing for better resolution and detection of breast cancer.
Studies have been conducted to compare 3-D mammography to regular screening mammography. There are some pluses and minuses for each technique. It is possible for screening mammography (as well as 3-D mammography) to miss a cancer in the breast. 3-D mammography appears to identify a few more breast cancers than regular mammography. In addition, fewer women have to be called back to get additional studies after their screening mammograms. The minuses include a higher cost for 3-D mammography, as well as a slightly higher radiation dose for each screening conducted. But since fewer women need to be called back for additional studies, any concern about increased radiation dose is probably a moot point.
Not all insurance companies cover the extra expense for 3-D mammography, so this could represent an out-of-pocket added expense. Medicare covers 3-D mammography.
For each individual woman, there is not necessarily a right or wrong answer about using 3-D mammography over regular mammography. There are women who may benefit from 3-D mammography. For women who have added risk factors, such as strong family history, personal history of breast cancer, or very dense breasts, 3-D mammography is preferred over standard digital mammography. For women who do not have dense breasts, and no risk factors, the regular mammography will be adequate. There seems to be a trend toward individualizing a mammography screening program, based on individual risk factors and priorities. Women should talk with their healthcare providers about which type of mammography is recommended for their needs and the availability of mammography units in their community.