Full-Body CT Scan: Safe?

(CBS)  A CT scan is widely used in medicine to help doctors diagnose disease by providing a detailed look inside a patient's body. It's more sensitive than a traditional X-ray but also delivers a more powerful dose of radiation.

But since whole-body CT scans to screen for disease are becoming more and more accessible to American consumers without the need for a doctor's referral or prescription, The Early Show medical correspondent Dr. Emily Senay reports there is a concern that the radiation may cause cancer if it's used on a regular basis without good reason.

A new study in the journal Radiology points out that the radiation from a full-body CT scan may actually raise the risk of cancer as it's trying to detect it. They looked at people who were exposed to radiation from atomic bombs in Japan during World War II in amounts equivalent to a full-body CT scan.

They estimate that one full-body CT scan at the age of 45 increases the risk of cancer by one in 1200. Not a huge risk. But if that same person gets the same scan every year until age 75, the risk of cancer goes up to one in 50. That's a big risk.

Since the jury is still out on whether there are benefits of full-body CT screening for a healthy person, this study is a red flag for people who might be tempted to get a CT scan without a doctor's referral.

If your doctor recommends a CT scan for a specific medical reason, then you shouldn't shy away from it. A CT scan is a wonderful tool that allows doctors to spot problems and confirm suspicions and proceed toward the treatment and cure of potentially fatal conditions. It may turn out that the radiation risk is worth it to screen high-risk people, such as those with a family history or genetic predisposition to cancer.

There are studies under way to see if CT scanning for cancer of the colon, or so-called virtual colonoscopy, and CT screening for lung cancer are worthwhile.

On the surface, a whole-body CT scan may seem like a good health-minded idea, but the results may give you a very mixed message. We don't yet know the balance between the possibility of discovering potentially life-saving information in a person who appears otherwise healthy, versus results of unknown significance that could lead to unnecessary invasive tests and the stress of worrying about the results.