Research On Construction Of Voxel Phantom Of Chinese Adult Female For Radiation Dosimetry

A voxel phantom of Chinese female called VPCF has been constructed. In this paperMonte Carlo simulations with FLUKA code were carried out to calculate the organ doseconversion coefficients (DCCs) for external photon irradiation with the irradiation conditionsAP and PA.A series of image processes including registration, segmentation etc. were carried out fordigitized virtual Chinese No.1female image database by using MATLAB R2010a andPhotoshop CS2software. Then3D reconstruction of the voxel model was achieved throughAmira software. After these processes, a voxel model comprised by total number of3,958,663voxels, each of which is size of1.61mm×1.61mm×5mm, was constructed. VPCF contained35organs，such as Tonsil, ovary, eyeball, lens, stomach, salivary gland, teeth, spleen, bladder,liver, heart, pancreas, gallbladder, breast, uterus, muscle, ET, trachea, esophagus, thymus,thyroid, skin, kidneys, adrenal, brain, lung, red marrow, large intestine and small intestine.By means of FORTRAN program, VPCF was adapted into FLUKA code. The FLUKAcode is then utilized for computation of dose conversion coefficients expressed in absorbeddose per air kerma or effective dose per air kerma free-in-air due to a broad parallel beam ofmono-energetic photons impinging in anterior–posterior (AP) and posterior–anterior (PA)directions of the20mono-energetic photon beams of energies in the range of20keV–10MeV.Some appropriate methods have been adopted for exacter dose calculation for special organs,such as bone surface, red bone marrow and skin.The data has adequately analyzed. The dosimetric differences were discussed through acomprehensive comparison of the resultant dose coefficients with those from ICRPPublication74, Regina and CRAM. Smaller differences for the effective dose conversioncoefficient are found than for the dose conversion coefficients in individual organs.Comparing with ICRP Publication74and CRAM, the VPCF’s effective dose conversioncoefficients were larger. In the energy range (20–80keV) the effective dose conversioncoefficients to VPCF in AP direction are equal to Regina but in AP direction about12.4%more than Regina. In the energy range (80keV–10MeV) the effective dose conversioncoefficients to VPCF in AP and PA direction are about0.85%more than Regina.