[ RadSafe ] Article: Teaching parents about CT risks might pare unnecessary scans in kids

[John Jacobus]

At
http://www.auntminnie.com/index.asp?Sec=sup&Sub=cto&Pag=dis&ItemId=74102&wf=1548&d=1

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Teaching parents about CT risks might pare unnecessary
scans in kids
12/28/2006
By: Eric Barnes
 
Doctors rarely tell parents about the radiation risks
associated with CT imaging of pediatric patients, and
understandably so. Time is in short supply. The
subject is complex, potentially troubling for parents,
and could lead to overconcern -- even to the detriment
of necessary imaging exams.

But a pilot study in Colorado found that parents can
be easily educated about radiation risks with the aid
of a short brochure -- and that they react quite well
to what they learn. Knowing CT scans aren't risk-free
might even reduce some of the demand for CT in
situations where it might not be needed, according to
the researchers.

At the 2006 RSNA meeting in Chicago, Dr. David Larson
from the University of Colorado Health Sciences Center
in Denver talked about the ongoing initiative, which
appears to have been successful in educating parents
whose children are referred for non-emergent CT scans.
Emergency departments are expected to be included as
the study expands.

The growing use of CT in children has led to
increasing radiation doses delivered to pediatric
patients; several studies have shown that patients and
parents are generally unaware of the risks and
radiation associated with CT exams, Larson said.

"Also, there is anecdotal evidence that suggests that
patients and parents may contribute to the demand for
CT, and this is especially concerning given the lack
of awareness of the risks," he said. "Our hypothesis
is that by informing parents of risks associated with
CT, we might help to reduce this demand, especially if
alternatives are available. But there's also a
legitimate concern that this may overly concern some
parents, and may actually talk some parents out of
doing CT when it is appropriately indicated."

The study sought to determine how a brief handout
about CT would affect parents' understanding of the
radiation and the cancer risk associated with CT,
Larson said. The researchers also wanted to know how
the brochure would affect parents' willingness to let
their children be scanned when necessary, and how it
would affect their willingness to consider an
alternative to CT "in a hypothetical situation where
observation would be available as an alternative,"
Larson said.

The study participants were the parents of pediatric
outpatients who were referred to a children's
hospital. Emergency department patients were excluded
for this stage of the study.

"We did the study by giving an initial survey, we gave
them the informational handout, then we administered a
final survey," Larson said. The administrative staff
ran the study, but parents could speak with a
radiologist if they had any questions, he added.

The two-page brochure briefly describing radiation and
risk took less than five minutes to read at an
eighth-grade level. The handout compared radiation
doses in common scans to typical exposure factors,
such as air travel.

The group then provided quantitative risk estimates to
patients using a 2001 study on head scan risk
estimates, and extrapolated it based on typical doses
given to the facility's pediatric population, Larson
said.

For example, a 1/3,000 lifetime attributable risk of
cancer from an abdominal CT scan was added to the
baseline cancer risk of 700/3,000 for a typical
pediatric patient who does not undergo CT. The
brochure explains that a single abdominal scan
increased the lifetime risk of developing cancer from
700/3,000 to 701/3,000, Larson said.

Of the 52 parents surveyed, before reading the
brochure 66% believed CT uses radiation, versus 99%
afterwards (p < 0.01), Larson reported. Before reading
the brochure 13% believed CT increases the lifetime
risk of cancer, versus 86% afterwards (p < 0.01).
After reading the brochure, parents became slightly
less willing to have their child undergo CT if their
doctor felt that either CT or observation would be
equally effective (p = 0.02), but their willingness to
have their child undergo a CT scan recommended by
their doctor did not significantly change. 

"No parent was unwilling to allow child to undergo CT
after reading this handout," Larson noted.

The last question asked about parents' willingness to
skip CT if the child's doctor thought observation
would be just as valuable. Before reading the
brochure, most parents either preferred CT or had no
preference; after the handout most preferred
observation.

Just one parent asked to speak to the radiologists to
clarify some information, Larson said.

"In conclusion we found that a brief informational
handout takes little time of parents," Larson said.
"We found that it is effective in helping parents
understand at least the basics, that CT does use
radiation and increases the risk of cancer. And we
found that it does not dissuade parents from allowing
a child to undergo CT when appropriate, nor does it
frighten them or make them overly concerned."

The idea for the brochure came up when emergency
department doctors called radiology looking for ways
they might dissuade parents who came in insisting on
CT scans for their children that the doctors felt were
weren't clinically indicated, or only marginally
indicated, Larson said.
  
Learning about the radiation risks of CT in the
brochure did not make parents less likely to allow
their children to be scanned when necessary (top
image). After reading the material, however, parents
were more likely to consider observation when the
physician felt it would be just as valuable as CT
(bottom image). The results suggest that education may
help wean parents away from demanding CT scans of
dubious clinical utility. 
  
Larson's RSNA audience was enthusiastic about the
handout, with a couple of attendees suggesting that
the group make it available to everyone -- and
especially in referring physicians' offices where most
scanning decisions are made. Larson said the brochure
will be made available to referring physicians, but
for the initial feasability study the researchers
wanted optimal control of the study conditions.

As for determining which CT scans might be skipped,
"we are going to try to define what is marginally
indicated without causing too much controversy,"
Larson said.

A PDF version of the brochure will be published soon
and will be available for download, Larson told
AuntMinnie.com.

By Eric Barnes
AuntMinnie.com staff writer
December 28, 2006

+++++++++++++++++++
On Nov. 26, 1942, President Roosevelt ordered nationwide gasoline 
rationing, beginning December 1.   

-- John
John Jacobus, MS
Certified Health Physicist
e-mail:  crispy_bird at yahoo.com

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