title: Personalized assessment of radiation risks from the one-stop-shop myocardial 256-slice CT examination.
abstract: BACKGROUND
  This study provides data on the cumulative life attributable risk (LAR) of radiation-induced cancer from the combination of coronary CT angiography (CCTA), dynamic CT perfusion (CTP) and delayed enhancement (DE) CT scans, required for reliable risk-benefit analysis of the one-stop-shop CCTA + CTP + DECT cardiac examination.
  
  
  METHODS
  Monte Carlo simulation of the dynamic CTP and DECT exposures on 62 adult individuals was employed to determine radiation absorbed dose to exposed radiosensitive organs. Corresponding data for CCTA were derived using patient chest circumference and previously published data. Individual-specific LARs of cancer were estimated using organ/tissue-specific radiogenic cancer risk factors. Total LAR from CCTA + CTP + DECT scans' sequence were estimated and compared to nominal intrinsic risk of cancer.
  
  
  RESULTS
  The main contribution, up to 80%, to cumulative radiation burden from CCTA + CTP + DECT scan-sequence was found to originate from the CTP scan. The total LAR from CCTA + CTP + DECT for females was found 4-6 times higher, compared to males. The mean cumulative risk of radiogenic cancer associated with the complete CCTA + CTP + DECT scan sequence was found to marginally increase the intrinsic risk for cancer induction by less than 0.6% and 0.1% for females and males, respectively.
  
  
  CONCLUSIONS
  The radiation risk from the 256-slice CCTA + CTP + DECT scan sequence may be considered low and should not constitute an obstacle for the clinical endorsement of the one-stop-shop cardiac CT examination, given that its clinical value has been well verified. Nevertheless, every effort should be made towards optimization of the dynamic CTP component which is the main contributor to patient radiation burden.
authors.affiliation: Department of Medical Physics, Faculty of Medicine, University of Crete, P.O. Box 2208, Heraklion, 71003 Crete, Greece. Electronic address: Kostas.Perisinakis@med.uoc.gr.
authors.forename: Kostas
authors.initials: K
authors.lastname: Perisinakis
authors.forename: Ioannis
authors.initials: I
authors.lastname: Seimenis
authors.forename: Antonis
authors.initials: A
authors.lastname: Tzedakis
authors.forename: Kostas
authors.initials: K
authors.lastname: Pagonidis
authors.forename: Antonios E
authors.initials: AE
authors.lastname: Papadakis
authors.forename: John
authors.initials: J
authors.lastname: Damilakis
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology; D004938:Esophageal Neoplasms / Q000453:epidemiology; D005260:Female; D006331:Heart Diseases / Q000000981:diagnostic imaging* / Q000453:epidemiology; D006801:Humans; D008175:Lung Neoplasms / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009010:Monte Carlo Method; D055414:Myocardial Perfusion Imaging / Q000009:adverse effects* / Q000379:methods / Q000706:statistics & numerical data; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology*; D011829:Radiation Dosage; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D014057:Tomography, X-Ray Computed / Q000009:adverse effects* / Q000379:methods / Q000706:statistics & numerical data
keywords: Cardiac computed tomography; Myocardial delayed enhancement; Myocardial perfusion imaging; Radiation risk