Children’s Radiation Exposure

Background

X-rays and CT (computed tomography) scans are useful diagnostic tools that use radiation to view bone and tissue inside the body. However, repeated exposure to radiation during a person’s life (cumulative exposure) can put them at higher risk for cancer.

CT scans are responsible for more than 40% of the cumulative diagnostic radiation exposures to patients. Medicare radiography costs are over $14 billion dollars a year and it is estimated that 20-50% of the scans are unnecessary.

Although there are times when a CT scan is the best tool to diagnose a medical condition, there are ways to minimize the patient’s exposure to radiation.

WSHA supports efforts to optimize radiation exposure in children by providing training, education, tools and patient education materials, as well as data. Strategies and measures have been developed in strong partnership with the 100K Children Campaign. For more information contact wshapatientsafety@wsha.org.

2017 Children’s Radiation Safety Toolkit

Strategies

1. Optimizing DLP (Dose Length Product) – ensuring that DLP is appropriate for a patient’s age and that protocols are structured to support imaging exam DLP end-values within acceptable ranges to optimize safety and ensure clinically viable images. WSHA supports Dose Index Registry as a platform.

2. Disseminating PECARN – educating ordering providers around identifying children at low risk for clinically important traumatic brain injuries may reduce unnecessary exams based on the 2009 Kuppermann study, thus optimizing when exams are ordered. WSHA supports R-SCAN as a platform. 

3. Supporting Child-Sized Protocols – adjusting the parameters of an exam to fit the pediatric patient based on age and/or size categories for imaging exam DLP end-values is expected to optimize safety and clinical image quality… noting that one size does not fit all. WSHA supports updating protocols to align with the age categories of the Dose Index Registry (ages 0 to 2, 3 to 6, 7 to 10, 11 to 14 and 15 to 18). Additional categories or subcategories may be determined by a physicist and radiologist.

Measure Definition Sheets

• DLP Dose Length Product CT Head Radiation Dose (see page 15 of the toolkit)
• PECARN Utilization (see pages 18 and 19 of the toolkit for a description)

DLP Values from 98,210 Pediatric Head CT Imaging Studies

• ACR DIR Sample Pediatric Report (page 18, column 2)

Data Set

• CT HEAD without contrast, DLP, Ages 0 to 2, N=14393 (216, 315, 452)
• CT HEAD without contrast, DLP, Ages 3 to 6, N=13359 (261, 388, 526)
• CT HEAD without contrast, DLP, Ages 7 to 10, N=13532 (342, 471, 628)
• CT HEAD without contrast, DLP, Ages 11 to 14, N=19085 (437, 602, 811)
• CT HEAD without contrast, DLP, Ages 15 to 18, N=37841 (566, 752, 951)

The above image is a representation of DLP data values from the 2016 July-December American College of Radiology’s Dose Index Registry (DIR) Pediatric Sample Report (page 18, column 2). The DIR was launched in 2011 and, as of July 2016, had data on 30.3 million examinations from 1524 facilities. This extensive participation and totally automated complete capture of all patient examinations enable the development of robust, clinically based national Diagnostic Reference Levels (DRLs) and Achievable Doses (ADs). However, DRLs and ADs have not been established for pediatric populations. These may be identified by 2020. 

Each of three lines above illustrates the 25-quartile (blue), median (green) and 75-quartile (yellow) for DLP values for five age categories. These data are from 98,210 Pediatric Head CT studies conducted nationwide. While the initiative lacks national benchmarks such as DRLs and Ads for pediatric imaging, these data in the image above are our current best estimate for optimal dose-to-image performance, irrespective of CT scanner brand, model or slice. Each trend line (red) displays a linear progression of the radiation typically required to produce viable images as patients’ age or size increase. 

• The 5 Million Examination Update (2013)
• Diagnostic Reference Levels (adults, 2017)

NEMA XR-29 (MITA Smart Dose) Standard

• American College of Radiology (ACR)
• National Electrical Manufacturers Association (NEMA)
• Medical Imaging & Technology Alliance (MITA)
• Dose Index Registry (DIR)

  • The XR-29 Standard specifies four attributes of CT scanners that “contribute to or help perform optimization and or management of doses of ionizing radiation while still enabling the system to deliver the diagnostic image quality needed by the physician.” CT scanners meeting the XR-29 Standard have the following:

  • DICOM-compliant radiation dose structured reporting (NEMA XR 29-2013)

    • ACR DIR Sample Pediatric Report 

    • ACR DIR Sample Adult Report 

  • Dose check features (NEMA XR 25-2010)
  • Automatic exposure control (NEMA XR-28-2013)
  • Reference adult and pediatric protocols (NEMA XR-28-2013)
• GE
• Philips
• Toshiba
• Siemens
• Neurologica
  

Dose Optimization:

Before using a CT scan, medical staff will be asked to consider alternatives. If they decide a CT scan is necessary, the dose should be adjusted for the size of the patient, including smaller doses for children.

• Webcast: Understanding Medical Radiation Exposure: What We Know and What We Don’t
  • Dose Reduction Process Flow Diagram  (accessible version)
  • CT Dose Monitoring Protocol
  • Children’s CT Reduction Calculator

Reduce Unnecessary Exposure – Right Order/Right Scan:

Implement protocols, procedures, algorithms, and guidelines to help your staff and clinicians make safer imaging choices for children.

• Webcast: Ultrasound for Appendicitis – Dose Optimization
  • Ultrasound for Suspected Appendicitis Protocol
  • Appendicitis Diagnosis Workflow  (accessible version)
  • RLQ Sonographer Worksheet – Final Version  (accessible version)
  • RLQ Radiologist Worksheet
• Webcast: Pediatric Head Trauma: When to Image
  • PECARN for Pediatric Head CT for Minor Head Trauma
  • Choosing Wisely Head CT Scan