title: Prospective measurement of patient exposure to radiation during pediatric ureteroscopy.
abstract: OBJECTIVE
  Few data have been reported regarding radiation exposure during pediatric endourological procedures, including ureteroscopy. We measured radiation exposure during pediatric ureteroscopy and identify opportunities for exposure reduction.
  
  
  METHODS
  We prospectively observed ureteroscopy procedures as part of a quality improvement initiative. Preoperative patient characteristics, operative factors, fluoroscopy settings and radiation exposure were recorded. Our outcomes were entrance skin dose and midline dose (both mGy). Specific modifiable factors were identified as targets for potential quality improvement.
  
  
  RESULTS
  Direct observation was performed in 54 consecutive ureteroscopy procedures. Mean±SD patient age was 14.8±3.8 years (range 7.4 to 19.2), with 9 children being younger than 12 years. Mean±SD entrance skin dose was 46.4±48 mGy. Mean±SD midline dose was 6.2±5.0 mGy. The most important major determinant of radiation dose was total fluoroscopy time (mean±SD 2.68±1.8 minutes) followed by dose rate setting, child anteroposterior diameter and source to skin distance (all p<0.01). Analysis of factors affecting exposure levels revealed that use of ureteral access sheaths (p=0.01) and retrograde pyelography (p=0.04) were significantly associated with fluoroscopy time. We also found that dose rate settings were higher than recommended in up to 43% of cases and ideal C-arm positioning could have reduced exposure by 14% (up to 49% in some cases).
  
  
  CONCLUSIONS
  Children receive biologically significant radiation doses during ureteroscopy procedures. Several modifiable factors contribute to dose and could be targeted in efforts to implement dose reduction strategies.
authors.affiliation: Department of Urology, Children's Hospital Boston, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Kokorowski
authors.forename: Jeanne S
authors.initials: JS
authors.lastname: Chow
authors.forename: Keith
authors.initials: K
authors.lastname: Strauss
authors.forename: Melanie
authors.initials: M
authors.lastname: Pennison
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Routh
authors.forename: Caleb P
authors.initials: CP
authors.lastname: Nelson
mesh_terms: D000293:Adolescent; D002648:Child; D006801:Humans; D011446:Prospective Studies; D058996:Quality Improvement; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000517:prevention & control*; D018666:Ureteroscopy / Q000009:adverse effects