Radiation From CT Scans Can Increase Risk of Cancer

If you have had any major illness in the past several years, you're likely familiar with the CT scan, or computerized tomography. Widely used to diagnose and screen for disease, CT scans have revolutionized radiology, allowing physicians to examine a patient's internal organs with incredible detail and accuracy.

In the last 20 years, the number of CT scans performed annually has increased from 3 million in 1980 to more than 60 million performed today — and more than 4 million on children. Though CT scans have created a revolution in detecting illness, they also come with a high degree of radiation exposure.

Troubling new information indicates that the increased use of CT scans could be leading to increases in cancer. Researchers now predict that in the coming decades, 1 percent to 2 percent of all cancers will be caused by the radiation received from CT scans.

In a recent article published in the New England Journal of Medicine, Dr. David Brenner and Dr. Eric Hall raised concerns that CT scans cause excessive radiation exposure, emitting 50-200 times more irradiation than an X-ray. The dose of radiation delivered in one or two CT scans is the same as standing two miles away from the site of an atomic bombing.

According to Brenner and Hall, increased use of CT scans has doubled the average American's exposure to radiation. For people who have received multiple CT scans, the risk of excessive radiation exposure is huge — in turn, the risk of cancer is huge as well.

As a diagnostic tool, CT scans save lives. They are invaluable for quick-response situations, often used in the emergency room to diagnose bleeding into the brain, strokes, the cause of abdominal pain and many other acute conditions. They are also widely used to diagnose and determine the spread of cancer, identify the cause of back and joint pains, and other challenging diagnoses.

Unfortunately, most physicians and patients see no downside to CT scans. In many cases, CT scans are used for monitoring a disease. I often see patients who have had an abdominal CT scan every three months to monitor a problem in the abdominal aorta. Millions of patients have unnecessary CT scans over — and over — again.

CT scans are also being used to detect illness in otherwise healthy individuals, despite the fact that there is little evidence to support it. This includes screening for lung disease in smokers, with whole-body scans to identify an unknown disease, and screening the heart to identify coronary artery disease.

Research shows that using CT scans in this manner has no proven value and, more importantly, it often leads to many additional unnecessary tests and procedures. It's estimated that as many as 20 million CT scans performed on adults and 1 million on children could be avoided. Scans for routine screening and unnecessary or too-frequent monitoring are exposing Americans to massive amounts of radiation.

The use of CT scans is convenient, noninvasive, and the results are impressive. It's no wonder that many physicians tend to do them frequently and without much thought. Making the situation even murkier is the number of CT scan machines. There are 26 machines for every 1 million Americans. They come with such a large price tag that physicians and hospitals must use them frequently to justify the cost.

When used appropriately, CT scans are invaluable tools for the medical community. However, there are alternatives to CT scans. For example, ultrasounds can be used to monitor diseases of the arteries, many abdominal conditions and can even be used to diagnose acute appendicitis. They are not invasive and don't irradiate. In some situations, an MRI is a good alternative. It is much more expensive, but does not lead to any irradiation exposure.

If you have had many CT scans, or know someone who has, don't panic. Your risk of cancer is increased, but the effect is still quite small. However, from now on, it's vital that you be more wary of any recommended scan. We must all be educated consumers to ensure that a CT scan is done for a good medical indication. Never have a CT scan for routine screening — the radiation risks are much too high.

Dr. David Lipschitz is the author of the book "Breaking the Rules of Aging." To find out more about Dr. David Lipschitz and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate Web page at www.creators.com. More information is available at www.drdavidhealth.com.

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