title: Development and validation of a GEANT4 radiation transport code for CT dosimetry.
abstract: The authors have created a radiation transport code using the GEANT4 Monte Carlo toolkit to simulate pediatric patients undergoing CT examinations. The focus of this paper is to validate their simulation with real-world physical dosimetry measurements using two independent techniques. Exposure measurements were made with a standard 100-mm CT pencil ionization chamber, and absorbed doses were also measured using optically stimulated luminescent (OSL) dosimeters. Measurements were made in air with a standard 16-cm acrylic head phantom and with a standard 32-cm acrylic body phantom. Physical dose measurements determined from the ionization chamber in air for 100 and 120 kVp beam energies were used to derive photon-fluence calibration factors. Both ion chamber and OSL measurement results provide useful comparisons in the validation of the Monte Carlo simulations. It was found that simulated and measured CTDI values were within an overall average of 6% of each other.
authors.affiliation: *Department of Radiology and Radiological Sciences, Vanderbilt University, 1161 21st Avenue, Nashville, TN 37232; †Rocky Mountain Oncology Center, 6501 E 2nd St, Casper, WY 82609; ‡Department of Radiology, Ochsner Medical Center, 1514 Jefferson Hwy, New Orleans, LA 70121.
authors.forename: D E
authors.initials: DE
authors.lastname: Carver
authors.forename: S D
authors.initials: SD
authors.lastname: Kost
authors.forename: M J
authors.initials: MJ
authors.lastname: Fernald
authors.forename: K G
authors.initials: KG
authors.lastname: Lewis
authors.forename: N D
authors.initials: ND
authors.lastname: Fraser
authors.forename: D R
authors.initials: DR
authors.lastname: Pickens
authors.forename: R R
authors.initials: RR
authors.lastname: Price
authors.forename: M G
authors.initials: MG
authors.lastname: Stabin
mesh_terms: D002648:Child; D003198:Computer Simulation; D006801:Humans; D009010:Monte Carlo Method; D019047:Phantoms, Imaging; D017785:Photons; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D011829:Radiation Dosage; D011834:Radiation Monitoring; D013051:Spectrometry, Gamma; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D019904:Polymethyl Methacrylate