Thursday, November 29, 2007

Sham: Unnecessary CT Scans are a Growing Cancer Risk

One of the fastest growing diagnostic tools in the medical world is the CT scan (Computed Tomography). It is estimated that more than 62 million CT scans per year are currently given in the United States, compared to three million in 1980. Doctors love the intense amount of detail provided in a CT, and many of them believe that it is the only way to examine certain organs or tissue. However, a new article in the New England Journal of Medcine cautions doctors that this remains a dangerous procedure, and that it is being used in some cases unnecessarily.

The amount of radiation received from a CT scan is about the same dose as that received by nuclear bomb survivors who lived two miles away from the explosions in Japan at the end of WWII. In other words, its a huge dose of radiation. And because we know of the health history of those Japanese survivors, we can assume that there will be later health problems with the huge numbers of people who are now getting CT scans.

David J. Brenner, Ph.D., and Eric J. Hall, Ph.D. (Center for Radiological Research at Columbia University Medical Center) argue that the potential carcinogenic effects from using CT scans may be underestimated or overlooked. This is of particular concern, because perhaps one-third of all CT scans performed in the United States may not be medically necessary, the radiation researchers say.

Because CT scans result in a far larger radiation exposure compared with conventional plain-film X-ray, this has resulted in a marked increase in the average personal radiation exposure in the United States, which has about doubled since 1980, largely because of the increased CT usage.

Drs. Brenner and Hall suggest that, in a few decades, a significant rise in the number of cancers in the United States will be seen, due to the radiation from CT scans now being performed.

The authorsl suggest three strategies for proactively addressing the potential increased radiation risks associated with CT scans:

1. Reduce the CT-related radiation dose in individual patients.

2. Replace CT use, when appropriate, with other options that have no radiation risk, such as ultrasound or magnetic resonance imaging (MRI).

3. Decrease the total number of CT scans prescribed.

Drs. Brenner and Hall suggest in their paper’s conclusion that these strategies could potentially keep 20 million adults and, crucially, more than one million children annually in the United States from being irradiated unnecessarily. They stress, however, that in the majority of individual cases, the benefits associated with a correct diagnosis through a properly prescribed CT scan will far outweigh the individual risk.


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