http://www.eurekalert.org/
Contact: Katie Hickling
press@plos.org
44-122-346-3330
Public Library of Science
Press release from PLoS Medicine
A new study published in this week's PLoS Medicine
aims to evaluate the possibility that exposure of a fetus to computed tomography
or radionuclide imaging performed during pregnancy might increase subsequent
risk of childhood cancer. The researchers concluded that despite the very
large size of their study they were unable to exclude the possibility of
a very slight risk, and advise that beta hCG testing (blood pregnancy test)
should continue to be done in all potentially pregnant women before undergoing
major radiodiagnostic testing. Similarly, use of lead apron shielding of
the pelvic area of pregnant women is also recommended. The research was
carried out by Joel Ray and colleagues from St. Michael's Hospital, Toronto,
Canada, and colleagues.
The authors used an anonymized database for
the whole province of Ontario, Canada (where universal health care is available
to all residents) to link maternal radiation exposure to a subsequent malignancy
in the child. Using this technique, the authors were able to follow up
1,835,517 mother-child pairs. In the entire dataset, 5,590 women were exposed
to radiodiagnostic testing during pregnancy; amongst the children born
to these exposed women, there were a total of four subsequent childhood
cancers. There were 1,829,927 women in the unexposed group (who did not
have radiodiagnostic imaging during pregnancy), and 2,539 cancers were
found amongst the children born to these women. The rates of childhood
cancer in exposed versus unexposed groups corresponds to a crude hazard
ratio of 0.69. However, there was still substantial uncertainty in this
study around the relative risk of malignancy following radiodiagnostic
testing. The researchers estimated an "adjusted hazard ratio" for the risk
to be 0.68, with confidence limits between 0.25 and 1.80. These confidence
intervals (representing uncertainty) suggest that although the researchers
did not find clear evidence for an increase in risk following imaging,
they could not exclude the chance of a small increase, up to 1.8 times
that in an unexposed pregnancy.
Given this possibility the authors recommend
that radiodiagnostic testing should be performed in pregnancy under urgent
or emergency situations, but that nonradiation-emitting imaging, such as
MRI and ultrasonography, be considered first, when clinically appropriate.
It should be emphasized that this study relates to the use of imaging modalities
such as computed tomography (and other forms of radionuclide imaging),
typically carried out to diagnose or exclude conditions encountered during
an emergency, such as pulmonary embolism or stroke – and not the routine
ultrasound scans done during pregnancy.
In an accompanying Perspective, Eduardo Franco
and Guy-Anne Turgeon from McGill University, Montreal, Canada recommend
that that an international consortium be formed to attempt to pool the
data on exposure-risk associations from all available investigations to
shed more light into this issue and assist policymakers in the future.
Funding: This study was funded by the Pediatric Oncology
Group of Ontario (POGO). JGR and AG are supported by Canadian Institutes
for Health Research New Investigator Award. This study was supported by
the Institute for Clinical Evaluative Sciences (ICES), which is funded
by the Ontario Ministry of Health and Long-Term Care (MOHLTC). The opinions,
results, and conclusions reported in this paper are those of the authors
and are independent from the funding sources. No endorsement by ICES or
the Ontario MOHLTC is intended or should be inferred. No funding bodies
had any role in the study design, data collection, analysis, decision to
publish or preparation of the manuscript.
Competing Interests: The authors have declared that no competing interests
exist.
Citation: Ray JG, Schull MJ, Urquia ML, You JJ, Guttmann A, et al.
(2010) Major Radiodiagnostic Imaging in Pregnancy and the Risk of Childhood
Malignancy: A Population-Based Cohort Study in Ontario. PLoS Med 7(9):
e1000337. doi:10.1371/journal.pmed.1000337
IN YOUR COVERAGE PLEASE USE THIS URL TO PROVIDE ACCESS TO THE FREELY
AVAILABLE PAPER: http://www.plosmedicine.org/
PRESS-ONLY PREVIEW OF THE ARTICLE: http://www.plos.org/press/
|
suite:
CONTACT:
Joel Ray
University of Toronto
Medicine
30 Bond St
Toronto, ON M5B 1W8
Canada
416 864-6060 Ext 6752
416 864-5485 (fax)
rayj@smh.toronto.on.ca
Julie Saccone
Senior Public Relations Specialist
St Michael's
SacconeJ@smh.ca
Related PLoS Medicine Perspective by Eduardo Franco and Guy-Anne Turgeon:
Funding: No specific funding was received for this article.
Competing interests: Eduardo Franco is on the Editorial Board of PLoS
Medicine.
Citation: Franco EL, Turgeon G-A (2010) Radiodiagnostic Imaging in
Pregnancy and the Risk of Childhood Malignancy: Raising the Bar. PLoS Med
7(9): e1000338. doi:10.1371/journal.pmed.1000338
IN YOUR COVERAGE PLEASE USE THIS URL TO PROVIDE ACCESS TO THE FREELY
AVAILABLE PAPER: http://www.plosmedicine.org/
PRESS-ONLY PREVIEW OF THE ARTICLE: http://www.plos.org/
CONTACT:
Eduardo Franco
McGill University
Division of Cancer Epidemiology
546 Pine Avenue West
Montreal, QC H2W1S6
Canada
1-514-398-6032
1-514-398-5002 (fax)
eduardo.franco@mcgill.ca
http://www.dotmed.com/news/story/14145/
NY raises awareness of CT radiation risks in pediatrics
September 07, 2010
by Heather Mayer, DOTmed News Reporter
The New York State Department of Health hopes
to raise awareness about radiation safety issues associated with computed
tomography imaging of children. The department said last week it will start
issuing pamphlets and child medical imaging cards, as part of the "Image
gently campaign: Working to change practice."
The campaign kicked off in 2007 by the Alliance
for Radiation Safety in Pediatric Imaging.
The state's DOH has partnered with the campaign
to raise awareness about potential radiation exposure risks from CT procedures
and advocate the use of low radiation doses when imaging children.
The education materials are being provided
to 16,000 pediatricians and physicians throughout the state, who will then
distribute them to parents and patients, the DOH said.
"CT imaging is an effective and widely
used diagnostic tool, but it should be performed in a manner that reduces
any undue risks to patients, especially children," said the state's
health commissioner, Dr. Richard Daines, in a statement. "Parents should
be aware of radiation safety issues for children and talk to their physicians
about which imaging options are appropriate for their child."
The educational pamphlet includes basic information
regarding X-rays and CT scans, their associated risks and the best scanning
strategies to reduce risks without compromising image quality. The imaging
card will allow parents to track dates and locations of imaging exams,
as well as the pediatrician's name and contact information.
"We are very pleased that New York has
recognized and promoted participation in the Image Gently campaign,"
said Shawn Farley, director of public affairs for the American College
of Radiology, in an e-mail to DOTmed News.
In order to reduce radiation exposure in the
pediatric population, New York's DOH and other health care groups promote
using alternative, non-radiation diagnostic imaging such as MRI and ultrasound,
limiting multi-slice CT imaging to specified areas and avoiding multiple
scans. The department also recommends using the lowest dose of radiation
based on factors such as the child's age and size, and encourages CT facilities
to obtain accreditation from ACR's CT accreditation program.
"Physicians should carefully weigh the
benefits of multi-slice CT scans versus alternative medical imaging procedures
when treating children and limit radiation dosages whenever possible,"
said Daines. "As the use of CT scans continues to grow, we need to ensure
that a child's safety remains the top priority."
The number of CT scans performed in the United
States is increasing 10 to 15% every year. It has grown from 3 million
scans in 1980 to 62 million in 2006. About 7 million CT exams are performed
on children each year, including 33% on children under the age of 10, according
to New York's DOH.
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