A study released this week in the medical journal Lancet provides the strongest evidence yet that CT scans in children are linked to elevated risk of developing cancer. As with all things involving radiation, and with all things involving cancer, it's complicated—and doesn't mean that CT scans aren't in some cases necessary. Here's a WSJ article summarizing the findings. "This paper confirms that radiation, even in relatively low doses, does lead to risk" of certain cancers, said Alan Craft, emeritus chair at Newcastle University and an author of the paper. "There is no safe dose." (via @moorehn)

  • jgs

    Was this not already known? It was certainly my layman’s understanding. 

    (Also I hear from the expert epidemiologists who staff the airport checkpoints that there is an exception to the ‘no safe dose’ rule for airport scanners. They’re perfectly safe.)

  • http://www.aarongilliland.com/ Aaron Gilliland

    This isn’t “time to start eating each other’s brains” level news.  It’s important, but just keep this in mind:

    1) The base rates are very low, so a doubling or tripling of cases is still a small number of people.  

    2) This is a retrospective, not a controlled study.  

    3) “There is no safe dose” does not imply “There is no acceptable risk”.

  • dioptase

    The evidence was strong enough that many hospitals stopped CTing kids at least 5 years ago.

  • http://decayfilm.com ssam

    Good to see some numbers, rather than just models based on linear no threshold. tricky numbers to crunch, because presumably all the children had some cause to be CT scanned in the first place.

    It would be interesting to compare to risks such as parents that smoke/drink, other medical procedures, or just general life risks. In the UK  (population ~62million) traffic kills 5000 people per year through polution, and 2000 in accidents, so roughly the same magnitude of risk as in this study.

  • drawthug

    Here’s a perspective from the American Association of Physicists in Medicine. In particular, it notes that older CT technology had doses “2 to 5 times higher than doses currently used on typical CT equipment.” It also mentions some previous comments (3x a very low risk is still a low risk & it is assumed that doctors ordered a scan for something that was a high risk). It also discusses some recommended congressional actions…

    http://www.aapm.org/publicgeneral/CTScansImportantDiagnosticTool.asp