Abstract: In order to improve the accuracy of dose calculation and meet the requirement of precise radiation protection, a complete method of dose calculation based on deformable mesh-type phantom was established, including the deformation algorithm of human mesh-type phantom and the high-speed Monte Carlo calculation method of this phantom. Algorithms of rigid rotation matrix, Laplacian volume map and As-rigid-as-possible transformance were used to deform the bone, soft tissue and internal organs respectively. The high speed Monte Carlo calculation of the phantom is based on Delaunay tetrahedralization technology. Based on this, a comparative test of dose calculation between the deformable mesh-type phantom and the non-deformable voxel phantom was carried out. The results show that, for squatting posture and bottom-up irradiating condition, the effective dose obtained by the mesh-type phantom is 51.2% higher and the organ dose is up to 98.6% higher than that obtained by the voxel phantom; for kneeling posture and antero-posterior irradiating condition, the effective dose obtained by the mesh-type phantom is 58.7% higher and the organ dose is up to 98.0% higher than that obtained by the voxel phantom. This paper focuses on breaking through the key techniques of the new generation of dose calculation technology, including the mesh-type phantom deforming algorithm and high speed Monte Carlo simulation method, which provides important support for the further development of high-precision dose calculation in China. In the future, it is expected to achieve accurate evaluation of personnel dose in precise radiation protection applications.

Key words: radiation dose, mesh-type phantom, deformability, tetrahedralization, precise radiation protection