Breast Computed Tomography (CT) as a Diagnostic Tool

Lay Summary

The American Cancer Society has recommended that all women over the age of 40 have an annual
mammogram for many years. This recommendation has been associated with a substantial
decrease in breast cancer deaths. When something suspicious is seen in one of these
mammograms, the woman is called back to the clinic for more imaging tests to better
determine if that suspicious feature might be breast cancer. These additional imaging tests
include repeated mammograms, magnification mammograms and/or ultrasound. Depending on what
is seen in these images, the radiologist will provide a diagnosis that the suspicion is
probably cancer, probably benign, or that the suspicion is a "false alarm." If it is a false
alarm, then the woman is sent home and she should come back after a year for another
standard annual mammogram. If the diagnosis is that it is probably benign, then the woman
should come back after 6 months so that the suspicion can be tested again. If the diagnosis
is that it is probably cancer, the woman is recommended to have a biopsy so that the cancer
can be confirmed. Both fortunately and unfortunately, 80% of the biopsies turn out to be
"false alarms." Although confirming that a woman does not have cancer is always a very good
thing, having put her through the anxiety, expense, and risk of a biopsy for what turned out
to be nothing should be avoided. Therefore, it would be desirable to reduce the number of
unnecessary biopsies that are performed.

Dedicated breast computed tomography (or breast CT), a new way of imaging the breast, has
been introduced in the last few years. Breast CT is an x-ray exam that uses 3D imaging to
show the breast in its real three dimensional shape. The investigators propose to use breast
CT as a new, better tool for the radiologist to perform the diagnosis, and therefore
hopefully result in fewer biopsies, which should decrease the "false alarms." Before breast
CT can be used clinically as a diagnostic tool, extensive testing must be performed. In this
first step, the investigators propose to acquire breast CT images of only 10 patients that
have been recommended to have biopsies, to see if the radiologist would have arrived at a
different diagnosis if he/she had based his/her decision on the breast CT images. Since this
has never been attempted before, this is an initial small study to test the feasibility of
this method.