title: The role of Size-Specific Dose Estimate (SSDE) in patient-specific organ dose and cancer risk estimation in paediatric chest and abdominopelvic CT examinations.
abstract: OBJECTIVE
  To develop a clinically applicable method to estimate patient-specific organ and blood doses and lifetime attributable risks (LAR) from paediatric torso CT examinations.
  
  
  METHODS
  Individualized voxel models were created from full-body CT data of 10 paediatric patients (2-18 years). Patient-specific dose distributions of chest and abdominopelvic CT scans were simulated using Monte Carlo methods. Blood dose was calculated as a weighted sum of simulated organ doses. LAR of cancer incidence and mortality were estimated, according to BEIR-VII. A second simulation and blood dose calculation was performed using only the thoracic and abdominopelvic region of the original voxel models. For each simulation, the size-specific dose estimate (SSDE) was calculated.
  
  
  RESULTS
  SSDE showed a significant strong linear correlation with organ dose (r > 0.8) and blood dose (r > 0.9) and LAR (r > 0.9). No significant differences were found between blood dose calculations with the full-body voxel models and the thoracic or abdominopelvic models.
  
  
  CONCLUSIONS
  Even though clinical CT images mostly do not cover the whole body of the patient, they can be used as a voxel model for blood dose calculation. In addition, SSDE can estimate patient-specific organ and blood doses and LAR in paediatric torso CT examinations.
  
  
  CONCLUSIONS
  • Blood dose can be simulated using the patient's clinical CT images. • SSDE estimates patient-specific organ/blood dose and LAR in paediatric CAP CT-examinations. • SSDE makes on-the-spot dose and LAR estimations possible in routine clinical practice.
authors.affiliation: Department of Basic Medical Sciences, Ghent University, Proeftuinstraat 86, 9000, Ghent, Belgium. caro.franck@ugent.be.
authors.forename: Caro
authors.initials: C
authors.lastname: Franck
authors.affiliation: Department of Basic Medical Sciences, Ghent University, Proeftuinstraat 86, 9000, Ghent, Belgium.
authors.forename: Charlot
authors.initials: C
authors.lastname: Vandevoorde
authors.affiliation: Nuclear Medicine Department, Ghent University Hospital, De Pintelaan 185, 9000, Ghent, Belgium.
authors.forename: Ingeborg
authors.initials: I
authors.lastname: Goethals
authors.affiliation: Radiology Department, Ghent University Hospital, De Pintelaan 185, 9000, Ghent, Belgium.
authors.forename: Peter
authors.initials: P
authors.lastname: Smeets
authors.affiliation: Radiology Department, Ghent University Hospital, De Pintelaan 185, 9000, Ghent, Belgium.
authors.forename: Eric
authors.initials: E
authors.lastname: Achten
authors.affiliation: Radiology Department, Ghent University Hospital, De Pintelaan 185, 9000, Ghent, Belgium.
authors.forename: Koenraad
authors.initials: K
authors.lastname: Verstraete
authors.affiliation: Department of Basic Medical Sciences, Ghent University, Proeftuinstraat 86, 9000, Ghent, Belgium.
authors.forename: Hubert
authors.initials: H
authors.lastname: Thierens
authors.affiliation: Department of Basic Medical Sciences, Ghent University, Proeftuinstraat 86, 9000, Ghent, Belgium.
authors.forename: Klaus
authors.initials: K
authors.lastname: Bacher
mesh_terms: D000005:Abdomen / Q000000981:diagnostic imaging*; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003198:Computer Simulation; D005260:Female; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D009010:Monte Carlo Method; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology* / Q000209:etiology; D058958:Organs at Risk; D010388:Pelvis / Q000000981:diagnostic imaging*; D011829:Radiation Dosage; D013909:Thorax / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000009:adverse effects* / Q000379:methods
keywords: Monte Carlo method; Paediatrics; Patient-specific computational modelling; Radiation dosimetry; X-Ray computed tomography