title: Effective and organ specific radiation doses from videourodynamics in children.
abstract: OBJECTIVE
  Effective and organ specific doses of ionizing radiation during videourodynamics are unknown. We estimated radiation exposure in children undergoing videourodynamics, and identified patient and examination factors that contribute to higher dosing.
  
  
  METHODS
  Fluoroscopy data were collected from consecutive patients undergoing videourodynamics. Documented dose metrics were used to calculate entrance skin dose after applying a series of correction factors. Effective doses and organ specific doses (ovaries/testes) were estimated from entrance skin dose using Monte Carlo methods on a mathematical anthropomorphic phantom (ages 0, 1, 5, 10 and 15 years). Regression analysis was performed to determine patient and procedural factors associated with higher dosing.
  
  
  RESULTS
  A total of 100 children (45% male, mean ± SD age 9.3 ± 5.7 years) were studied. Diagnoses included neurogenic bladder (73%), anatomical abnormality (14%) and functional/nonneurogenic disorder (13%). Mean fluoroscopy time was 0.17 ± 0.12 minutes. Mean age adjusted entrance skin dose, effective dose, and testis and ovary doses were 2.18 ± 2.00 mGy, 0.07 ± 0.05 mSv, 0.09 ± 0.10 mGy and 0.20 ± 0.13 mGy, respectively. On univariate analysis age, height, weight, body mass index, bladder capacity and fluoroscopy time were associated with effective dose. On multivariate adjusted analysis, body mass index, bladder capacity and fluoroscopy time were independently associated with effective dose.
  
  
  CONCLUSIONS
  The average effective dose of ionizing radiation from videourodynamics was less compared to voiding cystourethrogram dose reported in the literature. Greater fluoroscopy time, body mass index and bladder capacity are independently associated with higher dosing.
authors.affiliation: Department of Urology, University of Washington School of Medicine, Seattle, Washington.
authors.forename: Ryan S
authors.initials: RS
authors.lastname: Hsi
authors.forename: Jean
authors.initials: J
authors.lastname: Dearn
authors.forename: Melanie
authors.initials: M
authors.lastname: Dean
authors.forename: David A
authors.initials: DA
authors.lastname: Zamora
authors.forename: Kalpana M
authors.initials: KM
authors.lastname: Kanal
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Harper
authors.forename: Paul A
authors.initials: PA
authors.lastname: Merguerian
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D005471:Fluoroscopy / Q000379:methods*; D006801:Humans; D007223:Infant; D008297:Male; D010053:Ovary / Q000528:radiation effects; D011829:Radiation Dosage; D012189:Retrospective Studies; D012867:Skin / Q000528:radiation effects; D013737:Testis / Q000528:radiation effects; D014563:Urodynamics; D014741:Video Recording; D055815:Young Adult
keywords: AK; BMI; ED; ESD; air kerma; body mass index; effective dose; entrance skin dose; fluoroscopy; pediatrics; radiation dosage; urodynamics