Published Studies Establish
That CT Scans Cause Cancer
The last several months have presented one worrisome story after
another regarding the dangers of CT scans, including more than
200 patients receiving radiation overdoses while undergoing brain
There has been unpredictable and widespread variation in radiation
dosing for cardiac scans from one hospital to the next and a new
research report revealing that the cancer risk from radiation
in a CT scan may be far higher than was thought.
Two studies on this topic were published in the December 2009
issue of Archives of Internal Medicine. One of the studies reports
that just one scan can deliver enough radiation to cause cancer
and predicts that 29,000 new cancers will develop that can be
linked to CT scans received in just the year 2007. Making matters
much worse is the fact that the use of CT scans in medicine has
grown explosively -- more than tripling in the US since the 1990s,
with more than 70 million given each year.
Where it was previously thought that only those who underwent
numerous scans were in danger, the second of the published studies
shows that having had even one can boost cancer risk notably --
for example, a heart scan at age 40 would later result in cancer
in one in 270 women and one in 600 men. Abdominal and pelvic CT
scans raise the risk for cancer more than brain scans, and the
risk is far greater in younger patients, especially children.
The same researchers also noted huge variability in how much radiation
patients get, with some patients getting 10 or more times as much
radiation as others. There are a variety of reasons for this,
including equipment settings that aren't standardized and the
radiologist's decision about how much is necessary to capture
a high-quality image of a particular part of the body. Also, methods
for reducing radiation, such as adjusting for the size of the
patient, are underutilized. Yet another danger -- when equipment
is new and unfamiliar (as was the case with the California patients
who received overdoses) and technicians aren't properly trained,
the patient may receive unintended excess radiation.
What You Need To Know
The radiology community claims they are working to get these problems
under control. Meanwhile, however, it is not safe for each of
us as patients to pretend these problems don't exist while the
system sorts itself out -- at best, that will take years. It is
important to take steps now to minimize your risk. Here is what
you can do...
" Keep notes on all the scans you've had that you can remember
(ask family members if you are unsure), including the body area
and type of scan (x-ray or CT). If you have a chronic condition,
such as colitis or chronic lung disease, that necessitates multiple
imaging procedures, ask your doctor about other imaging options
that might be a good substitute for CT scans.
" Carry records with you. Keep and update a wallet-sized
card listing the imaging tests that you've had and where and when
each was done.
" If and when your doctor advises you to have a CT scan,
ask lots of questions. This is particularly important for tests
like cardiac CT scans that may not be strictly necessary, but
that your doctor may order to gather more information about your
overall health. Ask about the possibility of using alternative
imaging methods, such as MRI or ultrasound, neither of which uses
E. Stephen Amis, Jr., MD, professor and university chair, department
of radiology, Albert Einstein College of Medicine suggests:
- using language something like this: "I've seen a lot of
articles lately about some of these tests increasing your radiation
exposure. Please tell me what knowledge you hope to gain by having
me go through this CT scan. Is this test really necessary?"
The bottom line? Know the risks and be careful and be informed.
February 23, 2010