E. Stephen Amis, Jr., MD
E. Stephen Amis, Jr., MD, professor and chair, department of radiology at the Albert Einstein College of Medicine and chairman of radiology at Montefiore Medical Center, Bronx, New York.
First of all, let me say this: I don’t think anyone will argue with the idea that improved imaging tests — MRIs, CT scans and the like — have revolutionized medicine. Take CT scans, for example. This imaging technique creates highly detailed cross-sectional images of your body. These precisely detailed “slices” not only show bones, but also organs, blood vessels and other tissue, giving doctors information they need to diagnose muscle and bone disorders, pinpoint the location of a tumor, identify and monitor diseases such as cancer or heart disease, and detect internal injuries and internal bleeding, among other problems. In fact, the effectiveness of these imaging tests has profoundly changed the way medicine is practiced and they’ve helped doctors make decisions that have saved countless lives. But this progress comes at some cost — excessive exposure to radiation.
According to research revealed by the National Council on Radiation Protection’s 39th National Conference on Radiation Control, over the last two decades the per-capita dose of ionizing radiation from clinical imaging exams has grown six-fold. This is a huge increase but not a surprising one, given dramatic technological innovations in imaging tests that utilize radiation. Some startling numbers were also revealed in the “American College of Radiology White Paper on Radiation Dose in Medicine” published in the May 2007 issue of the Journal of the American College of Radiology. The number of CT scans performed each year grew from three million in 1980 to more than 60 million in 2005. The seven million nuclear medicine exams ordered in 1980 increased to 20 million in 2005.
So why is this a problem? According to the American College of Radiology report, “Ionizing radiation, especially at high doses, has long been known to increase the risk for developing cancer.” The paper also notes that the International Commission on Radiological Protection has reported that collective CT scan doses a patient receives can approach or exceed radiation levels that have been shown to increase risk for cancer. The obvious questions are: Does taking a test to prevent cancer actually give me cancer? What’s being done about this? Should we be worried? And what can a person do to protect him or herself?
To get to the important information and find out what we really need to know about this issue, I contacted E. Stephen Amis, Jr., MD, chair of radiology at both the Albert Einstein College of Medicine and Montefiore Medical Center in Bronx, New York, and lead author of the ACR’s white paper. He advises people to take an active role in their care, keeping track of imaging tests that involve radiation. This report was intended to raise awareness of the issue of cumulative radiation exposure, Dr. Amis says, not to scare anyone away from imaging exams they need. The goal is for both patients and health-care providers to be alert to the risks of cumulative radiation from imaging tests and take reasonable steps to reduce unnecessary exposure. The emphasis is on “unnecessary.”
Dr. Amis believes that, in general, the benefits of imaging tests far outweigh the risk of having them done. In fact, another article on the same subject, published in In Practice, a publication of the American Roentgen Ray Society (the oldest radiology society in the US), noted that “…of 62 million CT scans delivered in a year, nearly 14 million of those patients would die of cancer without the benefit of the scan.”
Dr. Amis stresses that the concern isn’t with the safety of the tests themselves — it is repeated exposure to radiation through imaging tests that the ACR is warning us about. “For example,” says Dr. Amis, “we’re worried about the 30-year-old with chronic kidney stones who comes to the emergency department every six months. He gets a CT scan every time he walks through the ER door — so after six years he’s had 12 scans.” In response to my question about the radiation exposure of, say, annual mammograms, Dr. Amis reassured me that traditional x-rays, like mammograms and chest x-rays, use significantly lower radiation doses and it would take many such exams to result in a cumulative exposure that might be worrisome. It’s the bigger exams — CT, full body imaging — that add up quickly.
This is where being an educated consumer comes into play. In order to minimize your risk but still receive the best medical care for your condition, you can ask your doctor questions — and keep records for yourself. Here’s what you need to remember…
Know the dose. Not all imaging exams use radiation — for example, ultrasound and MRI are radiation-free. And some (such as CT scans) provide a much higher dose than others (bone density tests and standard X-rays, for example, require very little radiation). To educate yourself about dose levels from various procedures, click on the “Safety” link at RadiologyInfo.org.
Keep track. If you have had numerous CT scans or other tests involving radiation (like Dr. Amis’ example of the patient with kidney stones) start keeping notes of the procedures you undergo, what they were for and when they were done. Then if a doctor recommends another such exam, you can refer to your previous history, voice your concerns and ask if a radiation-free alternative might be just as effective. For the kidney stone patient described above, an ultrasound or simple X-ray would likely have given sufficient information to help with a diagnosis, without adding to his radiation exposure.
Push back. In a serious medical situation, a CT scan or other higher-radiation-dose test could deliver the diagnosis that saves your life — and if that’s the case, you need to have it done. But if you feel that the procedure is unnecessary (either because you’ve been through it before or you suspect your doctor is being overly aggressive) and you don’t believe your concerns are being taken seriously, be vocal — get a second opinion or ask the radiologist or imaging specialist about alternatives. Or, if the situation is not acute and dangerous, consider waiting and seeking advice on less invasive options.
Remember, too, that money and convenience often play a role. Not only are these tests very profitable for hospitals, they also require an enormous capital investment in equipment — which is recouped by doing lots and lots of procedures. Also, the tests are fast, easy and painless for the patient, many of whom may feel especially well cared for when lots of tests are done.
“Everything in moderation” seems to once again be true. Being an informed consumer — and requesting radiation-free imaging tests whenever possible — will reduce your lifetime radiation exposure. By doing so, you can limit your doses to the times when no radiation-free alternative is available.
