Sun Sentinel Palm Beach Edition
Chest CT can’t replace screening
Dear Dr. Donohue: I am due to have a mammogram in July, but around the same time I am supposed to have a chest CT as a follow-up to my chondrosarcoma cancer. I have a CT every other year, and an X-ray on the opposite years of both my affected arm and my lungs. Does a chest CT have the potential of showing a similar finding as a mammogram? I would just as soon not have to expose myself to so much radiation all in one month. I’m 66. There is a history of postmenopausal breast cancer in my family, in my mother’s mother. — T.M.H.
A mammogram is an X-ray that is designed specifically to look for abnormalities in breast tissue. Mammograms have been extensively studied and proven to reduce mortality in women between the ages of 50-74 (outside these ages, there remains extreme controversy).
CT scans are X-rays taken from many angles and then reconstructed in a computer to provide a look at many slices of the part of the body being looked at. A CT scanner can be set to emphasize bones or soft tissue, and work is ongoing now with CT scans designed specifically for breast abnormalities. The CT scan you get as follow-up to your chondrosarcoma (a rare cancer of cartilage) is designed to look in lung tissue for abnormalities, and has not been evaluated as a means of screening for breast cancer, although I do know that some may be found anecdotally.
The CT scans you get as a part of your cancer follow-up are not an adequate substitute for ongoing mammography, which is particularly important in your case due to a family history.
I do understand the concern about radiation, but a mammogram has very little radiation — approximately the same you would get from naturally occurring radiation sources in seven weeks of walking around.