title: Absorbed fractions in a voxel-based phantom calculated with the MCNP-4B code.
abstract: A new approach for calculating internal dose estimates was developed through the use of a more realistic computational model of the human body. The present technique shows the capability to build a patient-specific phantom with tomography data (a voxel-based phantom) for the simulation of radiation transport and energy deposition using Monte Carlo methods such as in the MCNP-4B code. MCNP-4B absorbed fractions for photons in the mathematical phantom of Snyder et al. agreed well with reference values. Results obtained through radiation transport simulation in the voxel-based phantom, in general, agreed well with reference values. Considerable discrepancies, however, were found in some cases due to two major causes: differences in the organ masses between the phantoms and the occurrence of organ overlap in the voxel-based phantom, which is not considered in the mathematical phantom.
authors.affiliation: Instituto de Pesquisas Energéticas e Nucleares--IPEN-CNEN/SP, São Paulo, Brazil.
authors.forename: H
authors.initials: H
authors.lastname: Yoriyaz
authors.forename: A
authors.initials: A
authors.lastname: dos Santos
authors.forename: M G
authors.initials: MG
authors.lastname: Stabin
authors.forename: R
authors.initials: R
authors.lastname: Cabezas
mesh_terms: D000465:Algorithms; D004064:Digestive System / Q000000981:diagnostic imaging; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D008297:Male; D009010:Monte Carlo Method; D010179:Pancreas / Q000000981:diagnostic imaging; D019047:Phantoms, Imaging; D017785:Photons; D011874:Radiometry / Q000379:methods*; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D012984:Software; D013154:Spleen / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed