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Has Cancer Risk for Pediatric CT Increased Or Decreased? An Analysis of Cohort Data From 2004-2013
S Brady*, R Kaufman , St. Jude Children's Research Hospital, Memphis, TN
Presentations
MO-E-17A-9 Monday 1:45PM - 3:45PM Room: 17APurpose: To analyze CT radiation dosimetry trends in a pediatric population imaged with modern (2004-2013) CT technology
Methods: The institutional review board approved this retrospective review. Two cohorts of pediatric patients that received CT scans for treatment or surveillance for Wilms tumor (n=73) or Neuroblastoma (n=74) from 2004-2013 were included in this study. Patients were scanned during this time period on a GE Ultra (8 slice; 2004-2007), a GE VCT (2008-2011), or a GE VCT-XTe (2011-2013). Each patient's individual or combined chest, abdomen, and pelvic CT exams (n=4138) were loaded onto a PACS workstation (Intelerad, Canada) and measured to calculate their effective diameter and SSDE. Patient SSDE was used to estimate patient organ dosimetry based on previously published data. Patient’s organ dosimetry were sorted by gender, weight, age, scan protocol (i.e., chest, abdomen, or pelvis), and CT scanner technology and averaged accordingly to calculate population averaged absolute and effective dose values.
Results: Patient radiation dose burden calculated for all genders, weights, and ages decreased at a rate of 0.2 mSv/year (4.2 mGy/year; average organ dose) from 2004-2013; overall levels decreased by 50% from 3.0 mSv (60.0 mGy) to 1.5 mSv (25.9 mGy). Patient dose decreased at equal rates for both male and female, and for individual scan protocols. The greatest dose savings was found for patients between 0-4 years old (65%) followed by 5-9 years old (45%), 10-14 years old (30%), and > 14 years old (21%).
Conclusion: Assuming a linear-no-threshold model, there always will be potential risk of cancer induction from CT. However, as demonstrated among these patient populations, effective and organ dose has decreased over the last decade; thus, potential risk of long-term side effects from pediatric CT examinations has also been reduced.
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