title: Cumulative exposure to medical sources of ionizing radiation in the first year after pediatric heart transplantation.
abstract: BACKGROUND
  Pediatric heart transplant recipients undergo a variety of radiologic tests with the attendant risk of exposure to ionizing radiation. We sought to quantify and describe the cumulative exposure to all forms of medical radiation during the first year after pediatric heart transplantation and identify factors associated with higher exposure.
  
  
  METHODS
  Pediatric patients who received a heart transplant between January 2009 and May 2012 with follow-up at our institution were retrospectively reviewed. Patients were included if they survived through 1 year and the first coronary angiography. All medical testing using ionizing radiation performed during follow-up was compiled, and exposures were converted to effective dose (mSv).
  
  
  RESULTS
  Included were 31 patients who underwent heart transplantation at a median age of 13.6 years (range, 0.3-18.3 years). The median number of radiologic tests performed was 38 (range, 18-154), including 8 catheterizations (range, 2-12), and 28 X-ray images (range, 11-135). Median cumulative effective dose was 53.5 mSv (range, 10.6-153.5 mSv), of which 91% (range, 34%-98%) derived from catheterizations, 31% (range, 8%-89%) of the exposure occurred during the transplant admission, 59% (range, 11%-88%) during planned follow-up, and 3% (0%-56%) during unplanned follow-up. Older age at transplant was a risk factor for increased exposure (p = 0.006). When adjusted for age, a trend toward increased exposure was shown for congenital heart disease as the indication for transplant (p = 0.08), pre-sensitization (p = 0.12), and positive crossmatch (p = 0.09).
  
  
  CONCLUSIONS
  Pediatric heart transplant patients are exposed to significant amounts of ionizing radiation during the first post-transplant year, most during scheduled catheterization. As survival improves, considering the long-term risks associated with these levels of exposure is important.
authors.affiliation: Division of Cardiology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
authors.forename: Alicia
authors.initials: A
authors.lastname: McDonnell
authors.affiliation: Division of Cardiology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
authors.forename: Tacy E
authors.initials: TE
authors.lastname: Downing
authors.affiliation: Department of Radiology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Division of Cardiology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
authors.forename: Rachel
authors.initials: R
authors.lastname: Ryan
authors.affiliation: Division of Cardiology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Department of Pediatrics, The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Rossano
authors.affiliation: Division of Cardiology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Department of Pediatrics, The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania; Center for Clinical Epidemiology and Biostatistics, The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania. Electronic address: glatz@email.chop.edu.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Glatz
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003952:Diagnostic Imaging; D016027:Heart Transplantation; D006801:Humans; D007223:Infant; D011829:Radiation Dosage; D011839:Radiation, Ionizing; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors
keywords: cumulative exposure; ionizing radiation; pediatric heart transplant; radiologic tests