title: Radiation exposure after heart transplantation: trends and significance.
abstract: BACKGROUND
  Heart transplant recipients are frequently exposed to ionizing radiation from various imaging and cardiac procedures. However, radiation exposure carries various risks, including cancer. In this retrospective study, we calculated the mean cumulative radiation exposure during a 10-year period and the subsequent cancer risk after heart transplantation.
  
  
  METHODS
  The study included all patients who underwent heart transplantation from August 1998 to July 2008 at our center. We identified all plain X-ray images, computed tomography, nuclear medicine procedures, and cardiac procedures (endomyocardial biopsies, right and left heart catheterization, and coronary angiograms) each patient underwent during the follow-up period. Radiation doses from cardiac procedures were the recorded exposures, and we used reference values for plain X-ray imaging and nuclear medicine procedures.
  
  
  RESULTS
  The mean radiation dose was 84 mSv during the 10-year period, and cardiac procedures represented the largest radiation dose at 43.6 mSv (52%). The 10-year cumulative dose represented an additional 1 in 290 new cancers in the healthy population. Encouragingly, there was a decreasing trend of radiation exposure during the study period, with a mean decrease of 4.3 mSv per year.
  
  
  CONCLUSIONS
  Heart transplant patients are exposed to a 3.5 times greater dose of radiation per year compared with radiation from medical imaging in general population. The lifetime increase in cancer risk estimated from population studies was small. Although, there was a decreasing trend of radiation exposure during the study period, further reductions in radiation doses may be possible by the use of alternative imaging and non-imaging investigations.
authors.affiliation: Department of Cardiopulmonary Transplantation, Royal Brompton and Harefield NHS Foundation Trust, Harefield Hospital, Harefield, Middlesex, United Kingdom.
authors.forename: Mumin
authors.initials: M
authors.lastname: Noor
authors.forename: Jane
authors.initials: J
authors.lastname: Shekhdar
authors.forename: Nicholas R
authors.initials: NR
authors.lastname: Banner
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001706:Biopsy; D006328:Cardiac Catheterization; D017023:Coronary Angiography; D005260:Female; D005500:Follow-Up Studies; D016027:Heart Transplantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology*; D009683:Nuclear Medicine; D011829:Radiation Dosage; D011859:Radiography / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D018570:Risk Assessment; D014057:Tomography, X-Ray Computed; D055815:Young Adult