Do you think politicians or even the FDA could answer this question, posed by my friend Alan Tillotson?
Fact A : Herbs, vitamins and nutritional supplements caused zero deaths in 2008 [in most years actually]
Fact B: CT scans cause 30,000 new cancers and 14,500 deaths each year, with children being most at risk
Which of these answers is the correct political action to take?
A. We should crack down on the supplement industry
B. We should crack down on the CT scan industry
Government regulators seem to think choice “A” is best.
USA Today reported on two research studies published in the December 15
issue of Archives of Internal Medicine revealing that CT scans deliver far
more radiation than previously believed. In fact, the scans may actually be
responsible for nearly 30,000 cancers each year and 14,500 deaths.
One study, led by researchers from the National Cancer Institute, estimated the number of cancers that might be caused by the scans. The other study found that patients undergoing the scans may be exposed to up to four times
more radiation than previously estimated. Researchers studying 1119 patients at four San Francisco-area hospitals concluded that one CT scan could expose a patient to as much radiation as 74 mammograms or 442 chest X-rays.
Young people are at highest risk from excess radiation, partly because they have many years ahead of them during which radiation exposure can damage cellular DNA. For example, among 20-year-old women undergoing one coronary angiogram (CT scan of the heart), one in 150 will develop cancer specifically related to the procedure.
Not all doctors agree about those risks. Scientists have not yet determined whether low doses of radiation actually increase cancer risk or whether the risk rises only after exposure levels reach a certain threshhold, says James Thrall, chairman of the American College of Radiology.
He says it’s also tricky to compare cancer rates between people who have had CT scans with those who haven’t. People undergoing scans may have underlying health problems that predispose them to cancer, he says.
In many cases, CT scans can be lifesaving. In other cases, there’s no evidence a CT scan is really better than other approaches, Smith-Bindman says. Up to one-third of all CT scans are unnecessary, according to an accompanying editorial by Rita Redberg, also of UCSF.
Doctors sometimes order CT scans for convenience because they don’t have access to results at another facility, says Rosaleen Parsons, chair of diagnostic imaging at Philadelphia’s Fox-Chase Cancer Center, who wasn’t involved in the new studies.
She suggests that patients keep their medical records and ask doctors about alternatives that don’t involve radiation exposure.
We couldn’t agree more.