Mammograms Pose A Very Low Radiation Risk

December 11, 1985|By G. Timothy Johnson, M.D.

Dear Dr. Johnson: I keep hearing that modern mammograms are very safe because they have so little radiation. Is there really solid proof of this?

How does it compare in safety to some of the other methods of examining the breast?

There are basically two lines of evidence that suggest the danger of the radiation involved in modern mammography is extremely minimal -- or maybe even non-existent.

First, the incidence of breast cancer in women who have undergone mammography is no higher than in those who have not. Obviously, this kind of data needs to be pursued for a long period of time since the possible increased risk of breast cancer from radiation or any other source might not show itself for many years. But, the news so far is good.

Second, and just as important, is a comparison of the actual radiation involved in modern mammography with other kinds of radiation hazards we are constantly exposed to. For example, the amount of radiation from mammography is not much greater than the amount of background (natural) radiation we are exposed to simply by traveling in a car for 300 miles, or riding a bicycle out in the open for 10 miles. In short, while there is some radiation involved in mammography, it is truly minimal in the extreme.

In comparison, the thermogram (a picture generated by differences in temperature in different parts of the breast) involves no radiation. Unfortunately, it is not nearly as accurate in detecting small lumps, at least in its current form. Research is continuing, though, in hopes of making thermograms more precise as a screening tool. There is also some research evidence that the thermogram someday might be able to indicate areas of breast tissue that could become cancerous, before they actually do so.

Finally, I should point out that ultrasound examinations of the breast are really not used today for screening purposes, but as an adjunct to mammography once a suspicious area has been discovered. Ultrasound is useful in determining whether a suspicious area might be a cyst, and it does help to further differentiate between malignancy and other possible causes. Ultrasound cannot be used alone as an accurate screening tool, at least in present form. Is it true that you should brush your tongue when you brush your teeth?

The American Dental Association does recommend brushing your tongue as a way of removing bacteria from the mouth. I`m not sure that many people follow this advice, but it is on the books.