Do CT scans cause cancer?

Could radiation from the very CT scans that our doctors rely on be harming us?          

CT scan is short for computerized tomography scan. CT scans are a type of X-ray that provide highly detailed images.

Some fear that the ionizing radiation emitted from CT scans can harm DNA and cause tumors.

But the risk associated with these tests is worth the benefit, in most cases.

“There’s a risk of developing a tumor if you have a lot of CT scans, but that doesn’t usually happen unless you have a very serious life-threatening medical condition,” says Dianna Cody, Ph.D., professor of Imaging Physics at MD Anderson. “For most people, the benefits of the exam definitely outweigh the potential risks.”

Cody says radiation is more dangerous if it takes place on the same part of the body several times and with very high doses. So, radiation doesn’t tend to accumulate if you have five CT scans on five different parts of your body.

“Pay attention to the benefits of CT scans rather than the gloom and doom of some media reports,” Cody says. “CT scans have changed our lives for the better. They allow doctors to diagnose and treat patients much more quickly.”

Beware, though: Breast and thyroid tissue tend to be more sensitive to radiation. But women do not need to be wary of mammograms, which give off very little radiation.   

In addition, children’s rapidly dividing cells are vulnerable to radiation from any kind of X-ray. To make CT scans safer, providers use X-ray shields to protect sensitive areas and adjust doses to minimize the risk for younger patients.

Before your next CT scan

• Play it safe by asking the following questions next time a doctor prescribes a CT scan for you or your child. These questions will help you and your doctor decide if you or your child really need the exam.
• What do you expect to learn from this exam?
• Is a CT scan the best way to learn more about my condition?
• Is there a lower-risk option, such as an MRI or ultrasound?
• Will you adjust the dose for my child?
• Will X-ray shields be used to protect sensitive areas?
• Have you or another doctor run a CT scan on the same area of my body before?
• How many scans will be necessary? Should one or two be enough?
• May I have a copy of the scan and information about the dose?

Keep track of all of your CT scans by starting a file folder with dose information, copies of your scans and information on when you had each scan performed and what parts of the body were covered.

Talking to your doctor can help you stay healthy and ease any anxieties you might have regarding CT scans. 

Request an appointment at MD Anderson's Lyda Hill Cancer Prevention Center online or call 855-668-8897.