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A new study says that the average American is exposed to six times more radiation from medical tests than in the early 1980s, prompting warnings that physicians may be upping patients' cancer risk by giving them unnecessary exams. 

A study by The National Council of Radiation Protection and Measurements (NCRP) shows that the average American's overall radiation exposure jumped from 3.6 millisieverts (mSv) to 6.2 mSv per year -- almost entirely a result of radiation-based medical tests. These tests, once responsible for only 15 percent of Americans' exposure to radiation, now account for nearly 50 percent. In contrast, there was almost no change in so-called background radiation, which naturally emanates from soil, rocks and other environmental substances.

The increase in medical radiation exposure (from 0.53 mSv to 3.0 mSv) stemmed primarily from a rise in the use of computer tomography (CT) scans (which use x-rays to create cross sectional images of inside the body to spot tumors, clogged arteries, among other things), and nuclear imaging tests, which involve injecting radioactive chemicals into the bloodstream that can be picked up by special instruments and used to create images of the body's inner structures.

The advantage of these tests is that they are generally better for diagnosing conditions than older technologies [such as standard x-rays, which expose patients to much less radiation], says Arl Van Moore, president of the American College of Radiology. "But we are concerned about the overuse of radiation through self-referral," or doctors ordering exams that can be done in their own offices for their own financial benefit, he says.

Need medical tests and worried about radiation exposure? Walter Huda, a medical physicist at the Medical University of South Carolina in Charleston, advises that you press your doc on why he or she has ordered the exams – and ask whether the clinic is certified by the American College of Radiology to perform the tests.

One tidbit of good news from the report, says physicist David Schauer, NCRP's executive director: occupational exposure has been sliced in half during the same period. The major reason: employers have taken steps to protect them, such as installing lead-coated pipes in nuclear plants to prevent the escape of harmful radiation.

©iStockphoto.com/Snowleopard1  

4 Comments

1. 1. astromydude 08:55 PM 3/5/09

   I think it's a dilemma for the doctors as well in the face of oh so many medical litigations recently. Take example of the many types of brain tumors that are so difficult to diagnose without imaging technology. Understanding all of these will then lead you to a question: is "doctors ordering exams that can be done in their own offices for their own financial benefit" statement justifiable?

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2. 2. SmallBiz240 09:33 PM 3/5/09

   Astro, you are correct that physicians face legal pressures to act like other physicians. Many patients want sophisticated imaging, and the standard of care has changed over the years to provide this even for routine ailments like headaches and abdominal pain. It is very hard to put this genie back in the bottle, because anyone trying to "lead the charge" against high tech imaging must deviate from the "standard of care" to do so, and potentially put his or her career in jeopardy in a medicolegal sense. Also imaging provides such concrete answers, it's very seductive. As for self referral... Medical imaging utilization rates at self-referral locations - where the referring doctor makes money just for writing the imaging order - has increased at 3x the level that it has increased at non-self-referrer sites over the last few years. That's 3x the natural growth rate when there is no financial incentive. Physicians should make money by working, not by just scribbling an order. Unfortunately the Stark laws that aim to reduce self-referral are toothless due to countless exceptions, and apply only to Medicare/Medicaid, not to private insurance patients.

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3. 3. stillie 09:59 PM 3/5/09

   Wow, typically we don't have to worry about doctors for profit in Canada. Here we trust that they have our best interests in mind, not their own wallets, otherwise they would have made the trek southwards, I'm sure this is a generalization. As this is a science forum I digress.
   
   My son was diagnosed with cancer at the age of four months, he's had monthly CT scans and MiBG nuclear scans, and nuclear kidney function tests. We hate to think the treatment is a cause for future concern.

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4. 4. hanleym 04:39 PM 3/10/09

   Medical decisions always involve weighing the risks and benefits of a procedure or medication. CT scans that will potentially provide life saving information should not be avoided for fear of an assumed small increased risk of cancer. You can visit www.xrayrisk.com to calculate individual risk based on studies you have had.

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