Organ dose conversion coefficients on an ICRP-based Chinese adult male voxel model from idealized external photons exposures.

Department of Engineering Physics, Tsinghua University, Beijing, People's Republic of China.
Physics in Medicine and Biology (Impact Factor: 2.92). 11/2009; 54(21):6645-73. DOI: 10.1088/0031-9155/54/21/014
Source: PubMed

ABSTRACT A high-resolution whole-body voxel model called CAM representing the Chinese adult male was constructed in this paper based on a previous individual voxel model. There are more than 80 tissues and organs in CAM, including almost all organs required in the ICRP new recommendation. The mass of individual organs has been adjusted to the Chinese reference data. Special considerations were given to representing the gross spatial distribution of various bone constituents as realistically as possible during the construction of the site-specific skeleton. Organ dose conversion coefficients were calculated for six idealized external photon exposures from 10 keV to 10 MeV by using Monte Carlo simulation. The resulting dose coefficients were then compared with those from other models, e.g. CMP, ICRP 74, Rex, HDRK-man and VIP-man. Old and new effective male doses of CAM were calculated by using the tissue weighting factors from ICRP 60 and 103 Publications, respectively. Dosimetric differences between mathematical and voxel models, and the differences between Asian and Caucasian models are also discussed in this paper.

  • [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of this study is to quantify dosimetric differences if modern sophisticated voxel phantoms were used in the dosimetry system DS02 rather than the mathematical phantoms. The mathematical models (ADAM and EVA) and voxel phantoms (REX and REGINA) developed in Germany allow a useful comparison as they are very close in body weight, body height and organ masses. In this study, organ doses are calculated with published fluence-to-absorbed-dose conversion coefficients derived from those two model sets for unidirectional plane beam irradiation geometries, with DS02 photon energy spectra at various distances from the hypocentre in Hiroshima. Results showed that organ doses from mathematical models generally agree well with those from voxel phantoms except for a few organs at lateral irradiation geometries and eye lenses at antero-posterior irradiation, even though there were significant differences between the two phantom sets and various uncertainties in dose calculations.
    Radiation Protection Dosimetry 01/2012; 149(1):49-55. · 0.91 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The objective of this study was to develop a Voxel-based Chinese Reference female Phantom (VCRP-woman) from high-resolution color photographs acquired from an adult female cadaver. Forty-six organs/tissues, including all radiosensitive organs/tissues specified in the 2007 recommendations of the International Commission on Radiological Protection (ICRP), were either segmented manually or subjected to semi-automatic segmentation as seen in color photographs of the unadjusted female. A C++ program was developed to adjust the masses of the organs/tissues to values applicable to the Chinese Reference adult female. The resulting VCRP-woman consists of more than 106 million voxels, each with dimensions of 1.03 mm × 1.03 mm × 1.95 mm. Organ absorbed dose and effective dose conversion coefficients for monoenergetic photons from 0.015-10 MeV were calculated for several reference irradiation geometries (anterior-posterior, posterior-anterior, left-lateral, rotational, and isotropic) by Monte Carlo radiation transport. The results for the VCRP-woman were compared to those of the original (or unadjusted) female voxel phantom as well as the ICRP Publication 110 adult reference female computational phantom.
    Health physics 12/2013; 105(6):512-21. · 0.92 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A modification method was implemented to adjust the chest wall thickness of human voxel phantom for the purpose of numerical efficiency calibration of lung counters. This method was based on two basic mathematical morphology operations (dilation and erosion) and combined with proper structure elements. The voxel model of LLNL torso phantom was used as a reference to validate the modification process. The chest wall was mathematically modified from the starting phantom with no overlay plate to the target with an overlay plate of 24-mm thickness. The influences of different structure elements on detection efficiency were discussed. When diamond or square structure elements were used, the calculated efficiency was overestimated or underestimated by ∼40 % for 17.5-keV photons, compared with that of target phantom. In contrast, it was shown a good agreement with a deviation of <3 % when the hybrid structure elements were adopted. A similar adjustment method can be used for 3D modification of human voxel phantom to keep the body's anatomical geometry without distortion during the adjustment process.
    Radiation Protection Dosimetry 01/2014; · 0.91 Impact Factor


Available from
Jul 23, 2014