Tuesday, September 7, 2010

Medical Imaging: Too Much Radiation

Radiation exposure from medical imaging has increased seven-fold between 1980 and 2006, and now constitutes almost 50% of the lifetime dose of radiation received by the average American.  In fact, sophisticated new breast imaging technologies expose the patient to almost 30 times more radiation than a regular mammogram, thereby sharply raising the cancer risk caused by the imaging procedure itself.
Increased radiation exposure to the public from medical imaging is the focus of two recent studies by radiologists published last week in the journal Radiology. The first one, led by Dr. William Hendee, of the Medical College of Wisconsin,summarizes the conclusions of the August 2009 Medical Imaging Summit called by the American Board of Radiology Foundation. The study concludes that medical imaging is being overused.  This overuse creates the potential for higher radiation exposure for patients along with increased cancer risks. The study sees the problems created by the increased use of costly radiation-generating imaging technologies as a systemic issue which must be addressed globally within the health system. It holds the existing fee-for-service model, where physicians get paid more when they order more procedures, as one of the causes for the overuse of medical imaging.

The second study, led by Dr. Edward Hendrick, of the University Colorado-Denver School of Medicine, focuses on specific new imaging technologies using ionization radiation. The conclusion of the study is that some of these technologies, such as breast-specific gamma imaging (B.S.G.I.) and positron emission mammography (P.E.M.), results in radiation exposures 20 to 30 times high than a regular mammogram. It should be noted that these imaging technologies are not used for routine screening, like mammograms, but for very specific requirements, where the prescribing physician needs to do a risk/ benefit analysis of the use of the imaging technology vs. its risk.

Unfortunately, according to Dr. Hendrick, knowledge of radiation levels and risk is not well spread: “I would go to the international breast meeting and the big radiology meetings, and nobody had a clue what the doses and risks were. They are treating all the tests as if they have the same radiation dose and risk as mammography, and the truth is they have a much, much higher risk." Other specialists confirm the lack of knowledge of many practicing physicians: “this is something that isn’t well understood, not just by the public -  but by physicians who order the tests,” says Dr. Rhodes of the Mayo Clinic.

In a different but relevant story, the FDA is now looking into increasing oversight of several forms of medical radiation (also discussed in Business Week), following reports last year of patients being exposed to excessive doses of radiation in at least four hospitals across the nation, to the degree that many of them had lost their hair at the location of irradiation.

How does this affect you? You could end up being exposed to excessive radiation and subject to higher cancer risk, without even knowing about it. We cannot assume that the doctor knows best.

A few simple measures can reduce the dangers that and your family can be exposed to. Whenever a physician orders an imaging test for you or your family:
  • ask if the procedure is really necessary
  • discuss whether the data might not already be existing with another physician who could have ordered a similar test in the recent past (test duplication is a frequent cause of overexposure)
  • ask how much radiation you will be exposed to, and do not be satisfied with generalities (comparisons to a low-danger mammogram are a good way of understanding the risk)
  • if the physician cannot really give you an answer (quite likely), ask him about talking directly to the radiologist who will be administering the procedure, BEFORE you are set up to undergo the procedure
  • do not hesitate in asking for alternative providers for this procedure if you do not feel comfortable with the answers you are getting
  • discuss options for other imaging technologies that might expose you to less radiation
There is a silver lining to these stories. Radiologists themselves are raising critical issues and concerns that  are relevant to us - their patients. It is a good sign to see the practitioners themselves aware of the dangers that they created, and working to alleviate them.

Want to read more about it? Try the New York Times, Medical News Today, MedPage, Cardiovascular Business, DotMed Story1, RedOrbit, DotMed Story2, CBS News, UPI, Health Imaging, Modern Medicine, ACSH, or FoxNews.

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