Development of Chinese Female Computational Phantom Rad-Human and Its Application in Radiation Dosimetry Assessment

Dose conversion coefficients are important physical quantities in radiation dosimetry assessment and can be derived from Monte Carlo simulation based on human computational phantoms. In order to accurately evaluate the dose to a human body especially for a Chinese female, a precise whole-body Chinese female computational phantom named Rad-Human was constructed based on high-resolution digital color slice images of an adult female body. Rad-Human includes 46 tissues and organs with a minimum voxel size of 0.15 x 0.15 x 0.25 mm for head and neck and 0.15 x 0.15 x 0.5 mm for other regions, and it contains more than 28.8 billion voxels. Conversion coefficients and effective doses of external radiation, specific absorbed fractions, and S values of internal radiation for different energies for Rad-Human were calculated. The calculated dose conversion coefficients were reasonable comparing and analyzing the relationship between dose and organ characteristics with those values of the International Commission on Radiological Protection (ICRP) reference phantom. Based on the information and simulation results of Rad-Human, a set of more complete data of dose conversion coefficients in the radiation field was constructed for a Chinese adult female. Dose discrepancies that were observed were due to differences of body structures between the two phantoms. The differences of dose conversion coefficients between Rad-Human and the ICRP reference phantom demonstrate that Rad-Human can more accurately assess the exposure dose especially for a Chinese female.