A Lifesaving Investment: 3-D Mammography

CHRISTINA MARKS  2014

CHRISTINA MARKS  2014

I usually upgrade my smart phone every two years, when I renew my contract with AT&T.  In return for committing to another two years of service with AT&T, the newest smart phone is available for a discounted price (for example, we will assume it is $400 less and the final cost is $200).   The newest smart phone usually weighs less, has more storage space, has longer battery life, and also functions faster than the older smart phone.  The “last year” smart phone model is also available as an option.  Although still functional, it weighs more, has less storage space, has a shorter battery life, and functions slower.  But this phone is $500 less and the final cost is $100.  And then there is the flip phone.  We all remember owning a flip phone over ten years ago. We can’t imagine trading our smart phone for a flip phone now.   The flip phone is a steal at only $10.   It is tempting to opt for the “better deal” in these situations.  But I use my smart phone every day.  I use my smart phone for work, to call family and friends, to uber, to make dinner reservations…and the list goes on.  Given that the cost of the newest smart phone is only marginally more and will provide the daily benefits of having the newest technology, I upgrade to the newest smart phone. 

Although my smart phone is critical to get through my day, it is replaceable.  My health is not.  And just as new technologies have taken us from the era of the flip phone to the smart phone, breast imaging technology has evolved.  Having a screen-film mammogram is now as rare as a flip phone.  And while you won’t be asked if you want a screen-film mammogram upon arrival for your screening mammogram, you might be asked if you want a 2-D versus 3-D mammogram.   Both 2-D and 3-D mammograms are digital images that can be burned onto a CD at the conclusion of the exam.   Both exams take about the same amount of time.  Both exams will have similar reports generated by the radiologist who interprets your mammogram.  So what is the difference?  Why could you be asked to pay a small amount extra (usually about $50-$100) for the 3-D mammogram in addition to the fee charged to your insurance company for your screening mammogram?  And is that small fee really worth it? 

3-D mammography is what breast imagers refer to as Digital Breast Tomosynthesis (DBT).   This new imaging modality is approved by the FDA and obtains a series of 2-dimensional mammograms through the whole breast.   This series of low dose x-rays are then reconstructed as a 3-D mammogram for the radiologist to interpret.  

The standard 2-D digital mammogram is usually performed immediately prior to, or following, the DBT.  DBT is performed during the same compression as the 2-D mammogram, with the breast held in compression for only a few additional seconds (usually less than 10 seconds).   Therefore, similar compression of the breast is applied for both imaging techniques. 

While studies evaluating the benefits of DBT are ongoing, there are already results suggesting that the benefits of DBT include an increase in invasive cancer detection and a decrease in “call back” rate.  This translates into less anxiety from receiving that letter in the mail stating that you need to be called back for an abnormality on the screening mammogram and less anxiety waiting for days or weeks before going back to the breast imaging center for additional images.   One study published in the Journal of the American Medical Association (JAMA) in 2014 showed a 41% relative increase in invasive cancer detected with DBT, a 15% relative decrease in recall rate from screening mammography, and a 29% relative increase in the detection of all breast cancers.  This was no small study, with a total of over 450,000 examinations evaluated.

Despite these statistics, many insurance companies consider DBT “investigational” and therefore don’t cover the exam.  In 2014, the American College of Radiology addressed this stating that DBT was no longer investigational.  As of January 2015, Medicare will cover the costs of DBT as long as it is performed along with a 2-D mammogram.  If you want DBT and want to avoid receiving an unforeseen bill, call your insurance company before getting the mammogram to confirm whether or not they will cover the costs.  If they won’t cover the costs, most breast imaging centers will offer the option of DBT for an additional out-of-pocket fee of around $50-$100 dollars.   Why the additional fee?  Given more images of each breast to view, DBT takes more time for the radiologist, who must have special credentialing for DBT, to interpret.  Additionally, the x-ray machine that obtains 2-D mammograms cannot be upgraded with new software to perform 3-D mammograms.  Instead, new equipment (i.e. new x-ray machines and often image viewing stations and software) must be purchased to obtain and interpret 3-D mammograms.  Therefore, DBT is not available everywhere.

DBT in combination with 2-D mammography does increase the total amount of radiation exposure for the screening mammogram, however the benefit is decreased recall rates compared to 2-D mammography only.  This could ] translate into less radiation, in some cases, as DBT may illustrate that an area of concern on the 2-D mammogram is merely superimposed breast tissue avoiding the need for a “call back” for additional mammogram images (i.e. additional radiation, anxiety, and time spent waiting in the breast imaging center).  It is important to note though the total radiation dose of both a 2-D mammogram in combination with DBT is within the FDA-established acceptable dose for a mammogram, with the combination of both 2-D and DBT yielding about 2.5 cGy per view (below the FDA-established maximum per mammogram view of 3 cGy). 

Most of us are willing to spend an extra $100 to have the newest smart phone that weighs less, has more storage space, has longer batter life, and also functions faster than the older smart phone.  Are you willing to spend an extra $50-$100 to ensure that you have screening DBT?  For more about tomosynthesis, see Breast Cancer Screening Using Tomosynthesis in Combination with Digital Mammography by Friedewald et. al. JAMA. 2014;311(24):2499-2507.

 

Dr. Marks graduated from Millsaps College and the University of Mississippi Medical School. She completed her radiology residency at the University of Mississippi as well. Dr. Marks completed her Brem Fellowship in Breast Imaging and Intervention under the guidance of Dr. Rachel Brem. Dr. Marks is an attending physician at the University of Mississippi’s Breast Imaging Center.