1. University of Ulster, School of Life and Health Sciences.
Diagnostic Reference Levels for Paediatric Radiography of Chest, Abdomen and Pelvis in the UK: Optimising Radiation Protection.
Duffin S, McFadden SL
University of Ulster, School of Life and Health Sciences.
Background
The Health Protection Agency’s latest dose review1 made recommendations for acceptable Diagnostic Reference Levels (DRLs) for 52 types of examinations. Of the 52, only 5 relate to paediatric examinations, none of which relate to single radiograph examinations.
While European paediatric DRLs are available,2 they are considered unreliable and outdated.3,4 Furthermore, DRLs, as defined by ICRP,5 are intended to be specific to country or region.
The establishment of National paediatric DRLs for common plain film examinations are therefore of significant importance. Without such guidance there is potential for Employers across the UK to establish local DRLs that are essentially too high to detect recurrent over exposures to this vulnerable patient group.
Aim
To establish National DRLs (NDRLs) for standard paediatric radiography examinations of the chest, abdomen and pelvis in the UK.
Objectives
To collect UK paediatric dose data in relation to examination type and body part thickness.
To use National Radiological Protection Board /HPA recommendations1,6 to establish NDRLs based on the 75th percentile of data collected.
Methodology
140 radiology departments will be contacted to recruit a minimum sample of 10 hospitals, 20 rooms and 100 patients per DRL.1 Selection will be based on UK radiology workload and include specialised paediatric hospitals and general hospitals that facilitate paediatric radiography.1,7
Data collection packs will be distributed to designated lead radiographers in participating hospitals.
Parents/Guardians of patients meeting study criteria will be offered information sheets and invited to include the patient’s data in the study.
Formal consent will be gained using uniquely coded consent forms.
Data collection sheets will be anonymised, with the exception of the unique consent codes, and returned via secure courier for data collation.
Two data handlers will input and cross check data which will be checked for plausibility prior to inclusion.
Room mean doses will be calculated and inferences will be made about each set of non- parametric data.
DRL’s will be established for each standard-sized group for each examination type based on the 75th percentile of hospital room mean DAP distribution.
75th Percentile
Inclusion Criteria
Paediatric patients from new-born to aged 15 years.
CR and DR imaging systems.
Single radiograph AP/PA chest, AP Abdomen, and AP pelvis examinations.
Exclusion Criteria
Adults (16+).
Paediatrics with known underlying pathology.
Data with neither body part thickness or both height and weight measurements included.
Standard-sized age group allocation by examination type and body part thickness (cm) 6
Age Group
Chest (AP)
Chest (PA)
Abdomen (AP)
Pelvis (AP)
9.3
8.8
7.0 1
12.0
12.6
10.6 5
13.4
13.6
13.7 10
15.3
15.9
16.4 15
17.4
18.0
19.6
Factors aimed at increasing study’s success.
Large sample size (10% of UK radiology departments).
Voluntary Lead Radiographers to promote compliance.
‘Information for Radiographers’ to increase response rate and reduce response error.
‘Information for Parents/Guardians’ to increase participation.
Data collection sheets designed for ease of use.
Measuring instruments supplied to increase compliance.
Acceptance of weight and height in lieu of body thickness.
DAP dose measurements for convenience.
Data Analysis
Statistical packages will be used for descriptive and inferential statistics and various tests will be used to determine.
Standard error of mean for each dataset to indicate the significance of each DRL.
Dose variation between groups and the regression of mean dose and standard groups.
Association between age and patient size and between exposure, dose and patient size
Variation of mean doses between radiology departments.
Dose variation between specialised paediatric and general x-ray departments.
The effects various equipment and technical factors have on dose.
Value of Study
NDRLs for paediatric radiography of chest, abdomen and pelvis will prompt relevant departments to critically review paediatric practice in relation to these more common examinations and other paediatric X-ray examinations performed on similar equipment.3
Literature Cited
Hart D, Hillier MC, Shrimpton PC. Doses to Patients from Radiographic and Fluoroscopic X-ray Imaging Procedures in the UK – 2010 Review. Health Protection Agency. Report No: HPA-CRCE-034, 2012.
Kohn MM, Moores BM, Schibilla H, Schneider K, Stender HS, Stieve FE, Teunen D, Wall B. European Guidelines On Quality Criteria For Diagnostic Radiographic Images In Paediatrics. European Commission. Report No: EUR 16261EN, 1996.
IPEM. Guidance on the establishment and use of diagnostic reference levels for medical X-ray examinations. Institute of Physics and Engineering in Medicine. Report No: 88, 2004.
ICRP. Radiological Protection in Paediatric Diagnostic and Interventional Radiology. The International Commission on Radiological Protection. Report No: ICRP Publication 121, 2013.
ICRP. Radiological Protection and Safety in Medicine. The International Commission on Radiological Protection. Report No: ICRP Publication 73, 26(2), 1996.
Hart D, Wall BF, Shrimpton P, Bungay D, Dance D. Reference Doses and Patient Size in Paediatric Radiology. National Radiological Protection Agency. Report No: NRPB-R318, 2000.
Binley’s. The Health and Social Care Yearbook (The official handbook of the Institute of Healthcare Management). Basildon: Beechwood House Publishing; 2010.