Given these concerns, there is increased interest in breast imaging modalities other than digital mammography. Here are some of the most popular alternatives.
Digital breast tomosynthesis (3-D mammography)
We've previously written about the emergence of digital breast tomosynthesis (DBT), sometimes called 3-D mammography. Evidence continues to emerge that DBT may be more effective than digital mammography in detecting cancer and may decrease callback rates. We've spoken to some imaging programs that have made DBT the standard of care for women.
Medicare continues to cover DBT in conjunction with a 2-D digital mammogram and several private payers, including Cigna, Anthem, and UnitedHealthcare, provide national coverage. (Editor's note: The Reading Room is published by Advisory Board, a division of Optum, which is a wholly owned subsidiary of UnitedHealth Group. UnitedHealth Group separately owns UnitedHealthcare.)
However, some women are hesitant to make the switch to DBT because it emits twice as much radiation as a standard mammogram. The United States Preventative Services Task Force most recently graded DBT as an "I," saying that there is insufficient evidence to recommend DBT for all women or for those with dense breast tissue.
Breast MRI may be best for women with BRCA 1 or BRCA 2 genes, or for those with a family history of breast cancer. A study in the American Journal of Roentgenology found that for women in these groups, breast MRI identified 12 out of 13 (92.3%) cancers, whereas mammography only detected four of the 13 (30.8%).
However, MRI continues to be criticized for its low specificity, as it rarely identifies a potential lesion with enough specificity to determine if it is cancerous and often requires additional imaging or biopsy. The test frequently results in false positives, leading to increased spending, more time waiting, and higher levels of patient anxiety.
The test's cost is also a common concern for patients. MRI tends to be more expensive than mammography, and some payers do not cover the exam, even for high-risk women.
Ultrasound alone is not accepted as a breast cancer screening tool, as it often generates false positives as well as false negatives. However, breast ultrasound is frequently used as a follow-up screening modality. One study found that using breast ultrasound to supplement mammography in women with dense breast tissue detected more cancers that mammography alone.
One drawback to breast ultrasound is that the effectiveness is dependent on the skill of the technologist, which can lead to inconsistencies. As a solution, imaging programs are beginning to use automated breast ultrasound (ABUS) as an alternative to traditional hand-held ultrasound. ABUS uses high-frequency sound waves to present a 3-D image of the breast. These images are better suited for women with dense breasts because they allow radiologists to check the breast from a variety of angles and offer a better interpretation.
Despite FDA approval of ABUS for screening, insurance coverage is not necessarily available.. If an insurer doesn't cover the test, high out-of-pocket costs—which can reach $500—may deter patients.
Other technologies to watch
While DBT, MRI, and ultrasound represent the most popular alternatives to digital mammography, there are other screening options available. Some of these technologies include:
- Thermography: Thermal imaging uses a camera to measure the temperature of the patient's skin to determine if cancer cells are cells are growing or multiplying in the breast.
- Molecular Breast Imaging: MBI represents a class of novel nuclear medicine imaging modalities designed to provide high-resolution functional imaging of breast tissue.
- Low-dose mammography: Low-dose mammography employs a single-emulsion film and a high-definition intensifying screen to reduce radiation dosage and enhance the contrast of soft tissue structures in the breast.
- Contrast enhanced digital mammography: CEDM uses mammography and a standard iodinated IV contrast agent to make cancers that are not visible on standard mammograms show up as enhancing areas.
Outlook for these modalities
While these technologies may not be new, their use has traditionally been limited. That may be changing, as states increasingly adopt breast density notification legislation. While many of these laws require only that imaging programs notify women of their density status and potential subsequent screenings, other states are going a step further and requiring payer coverage of these imaging tests.
Research indicates that notification combined with these coverage provisions can change utilization of breast imaging modalities. One study in the Journal of the American College of Radiology found that the New Jersey Breast Density Law successfully publicized the complications of high density breast tissue, leading to an increase in alternative imaging utilization. In one year, screening ultrasound increased by 651% and MRI use grew by 59.3%. As more states adopt this type of density notification model, imaging programs should be prepared for similar increases.