title: Effective dose estimation for pediatric upper gastrointestinal examinations using an anthropomorphic phantom set and metal oxide semiconductor field-effect transistor (MOSFET) technology.
abstract: BACKGROUND
  There is a need for updated radiation dose estimates in pediatric fluoroscopy given the routine use of new dose-saving technologies and increased radiation safety awareness in pediatric imaging.
  
  
  OBJECTIVE
  To estimate effective doses for standardized pediatric upper gastrointestinal (UGI) examinations at our institute using direct dose measurement, as well as provide dose-area product (DAP) to effective dose conversion factors to be used for the estimation of UGI effective doses for boys and girls up to 10 years of age at other centers.
  
  
  METHODS
  Metal oxide semiconductor field-effect transistor (MOSFET) dosimeters were placed within four anthropomorphic phantoms representing children ≤10 years of age and exposed to mock UGI examinations using exposures much greater than used clinically to minimize measurement error. Measured effective dose was calculated using ICRP 103 weights and scaled to our institution's standardized clinical UGI (3.6-min fluoroscopy, four spot exposures and four examination beam projections) as determined from patient logs. Results were compared to Monte Carlo simulations and related to fluoroscope-displayed DAP.
  
  
  RESULTS
  Measured effective doses for standardized pediatric UGI examinations in our institute ranged from 0.35 to 0.79 mSv in girls and were 3-8% lower for boys. Simulation-derived and measured effective doses were in agreement (percentage differences <19%, T > 0.18). DAP-to-effective dose conversion factors ranged from 6.5 ×10(-4) mSv per Gy-cm(2) to 4.3 × 10(-3) mSv per Gy-cm(2) for girls and were similarly lower for boys.
  
  
  CONCLUSIONS
  Using modern fluoroscopy equipment, the effective dose associated with the UGI examination in children ≤10 years at our institute is < 1 mSv. Estimations of effective dose associated with pediatric UGI examinations can be made for children up to the age of 10 using the DAP-normalized conversion factors provided in this study. These estimates can be further refined to reflect individual hospital examination protocols through the use of direct organ dose measurement using MOSFETs, which were shown to agree with Monte Carlo simulated doses.
authors.affiliation: Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Canada.
authors.forename: Brent
authors.initials: B
authors.lastname: Emigh
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Gordon
authors.forename: Bairbre L
authors.initials: BL
authors.lastname: Connolly
authors.forename: Michelle
authors.initials: M
authors.lastname: Falkiner
authors.forename: Karen E
authors.initials: KE
authors.lastname: Thomas
mesh_terms: D002648:Child; D002675:Child, Preschool; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D005471:Fluoroscopy / Q000295:instrumentation*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011874:Radiometry / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014173:Transistors, Electronic; D041742:Upper Gastrointestinal Tract / Q000000981:diagnostic imaging*; D014965:X-Rays