Research On The Voxel Model Of Chinese Reference Adult Woman For Radiation Dosimetry

A voxel model of Chinese Reference Adult Woman (CRAW) has been constructedaccording to the Chinese reference data based on a Chinese female voxel model called VPCFin this paper. Monte Carlo simulations with FLUKA code were carried out to calculate theorgan dose conversion coefficients and effective-female-dose for external photon, proton,positive and negative pion irradiation with the irradiation conditions AP and PA，respectively.Based on the previous Chinese individual female voxel model called VPCF, the CRAWmodel was developed according to Chinese reference data and the skeleton tissue distributiondata from ICRP publication. The content of the19skeleton parts of the skeleton tissues wascalculated according to the ICRP skeleton data, then special considerations were given torepresenting the spatial distribution of various bone constituents as realistically as possibleduring the construction of RBM-site-specific skeleton voxel model, which the methodcombined with the Chinese Reference Adult Man and Chinese adult female voxel modelVPCF. The method of “dilate” and “erode” in Matlab and the Photoshop manual segmentationmethod are used to adjust the organ volume according to the Reference data. The model has aheight of158cm and a weight of54kg, and the voxel size of the model is1.774mm×1.774mm×4.85mm. The CRAW model contains more than37primary organs andtissues.By using the Monte Carlo code FLUKA, the CRAW voxel model has been used tocalculate the external dose conversion coefficients for Chinese adult woman in the directionof anterior-posterior(AP) and posterior-anterior(PA). The energy ranges selected for the dosecoefficient data set are20keV-10MeV,0.02GeV-10TeV, and0.001GeV-10TeV for photons,protons, positive and negative pions, respectively. And appropriate methods have beenadopted for special organs, such as skin, red bone marrow and bone surface to make theresults reasonable.A series of factors including irradiation geometry conditions, location and size of organand the personal difference are analysed and discussed in detail for the deviations of the organdose. The results of the comparision show that the deviations for low energy incident particlesin AP direction are larger, while for the high-energy particles are smaller.