Research On Human Internal Radiation Dosimetry Based On The Individuation Boundary Representation Phantoms

In the field of nuclear energy,nuclear technology and nuclear medicine,the professional,the public and the patients can receive internal irradiation from inhaling or ingesting radioactive materials,during work,nuclear accidents and the process of internal radiation therapy.In order to protect human from irradiation damage,it is necessary to assess internal dose accurately.The Anthropomorphic Computational Phantoms are applied to the research of human radiation dose extensively.Among them,the BREP(Boundary Representation)phantoms draw the attention of researchers increasingly,because they not only can be adjusted flexibly like mathematical phantoms,but also reflect the fine anatomical structure like voxel phantoms.Based on the Chinese reference adult female BREP phantom and referring to the reference data of the Chinese,Asia and ICRP Female,three individuation BREP phantoms called F1,F2 and F3 were established through adjusting the height of the phantom,the volume and the location of organs or tissues using the method of BREP in Rhinoceros.The BREP phantoms were processed into three-dimensional voxel matrix using BIN VOX software in order to be imported into Monte Carlo program.After importing the individuation BREP phantoms F1,F2 and F3to MCNP program,the self absorbed fractions,mutual absorbed fractions and the specific absorbed fractions of each organs or tissues under 12 photon monoenergetic beams from 0.01 MeV to 4MeV were calculated and the results were compared among individuation phantoms.The results showed that the differences among the self absorbed fractions are less than 15%,but the differences in mutual absorbed fractions and specific absorbed fractions are obvious due to differences in mass and location of organs.Using SIMULINK simulation software in MATLAB,the Human Respiratory Tract and the Human Alimentary Tract biological dynamics simulation model were constructed separately,according to the publications of ICRP.The simulation results are in great agreement with that calculated by publications of ICRP.Thus,the biological dynamics simulation model can be used as a tool to simulate the metabolism of specific radionuclides in vivo accurately.Finally,taking the inhalation of 1-131 as an example,calculate and compare the internal irradiation conversion coefficients by combing the individuation BREP phantom with the Human Respiratory Tract Simulation Model.The example describes the application of the BREP phantom and biological dynamics model in internal irradiation dosimetry perfectly.