TY - JOUR
T1 - International variation in radiation dose for computed tomography examinations
T2 - prospective cohort study
AU - Smith-Bindman, Rebecca
AU - Wang, Yifei
AU - Chu, Philip
AU - Chung, Robert
AU - Einstein, Andrew J.
AU - Balcombe, Jonathan
AU - Cocker, Mary
AU - Das, Marcos
AU - Delman, Bradley N.
AU - Flynn, Michael
AU - Gould, Robert
AU - Lee, Ryan K.
AU - Yellen-Nelson, Thomas
AU - Schindera, Sebastian
AU - Seibert, Anthony
AU - Starkey, Jay
AU - Suntharalingam, Saravanabavaan
AU - Wetter, Axel
AU - Wildberger, Joachim E.
AU - Miglioretti, Diana L.
N1 - Funding Information:
Funded by the US National Institutes of Health (R01-CA181191); Patient-Centered Outcomes Research Institute (CD-1304-7043); Centers for Disease Control and Prevention; and the University of California Office of the President, Center for Health Quality and Innovation; Chris Tachibana edited this manuscript, funded by Kaiser Permanente Washington Health Research Institute. Funders had no role in study design, collection, analysis, interpretation, and reporting of data; or decision to publish.
Publisher Copyright:
© 2019 BMJ Publishing Group. All rights reserved.
PY - 2019/1/2
Y1 - 2019/1/2
N2 - OBJECTIVETo determine patient, institution, and machine characteristics that contribute to variation in radiation doses used for computed tomography (CT).DESIGNProspective cohort study.SETTINGData were assembled and analyzed from the University of California San Francisco CT International Dose Registry.PARTICIPANTSStandardized data from over 2.0 million CT examinations of adults who underwent CT between November 2015 and August 2017 from 151 institutions, across seven countries.MAIN OUTCOME MEASURESMean effective doses and proportions of high dose examinations for abdomen, chest, combined chest and abdomen, and head CT were determined by patient characteristics (sex, age, and size), type of institution (trauma center, care provision 24 hours per day and seven days per week, academic, private), institutional practice volume, machine factors (manufacturer, model), country, and how scanners were used, before and after adjustment for patient characteristics, using hierarchical linear and logistic regression. High dose examinations were defined as CT scans with doses above the 75th percentile defined during a baseline period.RESULTSThe mean effective dose and proportion of high dose examinations varied substantially across institutions. The doses varied modestly (10-30%) by type of institution and machine characteristics after adjusting for patient characteristics. By contrast, even after adjusting for patient characteristics, wide variations in radiation doses across countries persisted, with a fourfold range in mean effective dose for abdomen CT examinations (7.0-25.7 mSv) and a 17-fold range in proportion of high dose examinations (4-69%). Similar variation across countries was observed for chest (mean effective dose 1.7-6.4 mSv, proportion of high dose examinations 1-26%) and combined chest and abdomen CT (10.0-37.9 mSv, 2-78%). Doses for head CT varied less (1.4-1.9 mSv, 8-27%). In multivariable models, the dose variation across countries was primarily attributable to institutional decisions regarding technical parameters (that is, how the scanners were used).CONCLUSIONSCT protocols and radiation doses vary greatly across countries and are primarily attributable to local choices regarding technical parameters, rather than patient, institution, or machine characteristics. These findings suggest that the optimization of doses to a consistent standard should be possible.
AB - OBJECTIVETo determine patient, institution, and machine characteristics that contribute to variation in radiation doses used for computed tomography (CT).DESIGNProspective cohort study.SETTINGData were assembled and analyzed from the University of California San Francisco CT International Dose Registry.PARTICIPANTSStandardized data from over 2.0 million CT examinations of adults who underwent CT between November 2015 and August 2017 from 151 institutions, across seven countries.MAIN OUTCOME MEASURESMean effective doses and proportions of high dose examinations for abdomen, chest, combined chest and abdomen, and head CT were determined by patient characteristics (sex, age, and size), type of institution (trauma center, care provision 24 hours per day and seven days per week, academic, private), institutional practice volume, machine factors (manufacturer, model), country, and how scanners were used, before and after adjustment for patient characteristics, using hierarchical linear and logistic regression. High dose examinations were defined as CT scans with doses above the 75th percentile defined during a baseline period.RESULTSThe mean effective dose and proportion of high dose examinations varied substantially across institutions. The doses varied modestly (10-30%) by type of institution and machine characteristics after adjusting for patient characteristics. By contrast, even after adjusting for patient characteristics, wide variations in radiation doses across countries persisted, with a fourfold range in mean effective dose for abdomen CT examinations (7.0-25.7 mSv) and a 17-fold range in proportion of high dose examinations (4-69%). Similar variation across countries was observed for chest (mean effective dose 1.7-6.4 mSv, proportion of high dose examinations 1-26%) and combined chest and abdomen CT (10.0-37.9 mSv, 2-78%). Doses for head CT varied less (1.4-1.9 mSv, 8-27%). In multivariable models, the dose variation across countries was primarily attributable to institutional decisions regarding technical parameters (that is, how the scanners were used).CONCLUSIONSCT protocols and radiation doses vary greatly across countries and are primarily attributable to local choices regarding technical parameters, rather than patient, institution, or machine characteristics. These findings suggest that the optimization of doses to a consistent standard should be possible.
KW - IONIZING-RADIATION
KW - CT
KW - RISK
KW - CHILDHOOD
KW - EXPOSURE
KW - CANCER
KW - SCANS
U2 - 10.1136/bmj.k4931
DO - 10.1136/bmj.k4931
M3 - Article
C2 - 30602590
SN - 1756-1833
VL - 364
SP - 1
EP - 12
JO - BMJ
JF - BMJ
M1 - 4931
ER -