Development of a 3D human body library based on polygonal mesh surface for whole body counter set-up calibration

Abstract

A Whole Body Counter (WBC) is a common facility to routinely assess the internal contamination of exposed workers and especially in the case of radiation release accidents. The calibration of the counting device is usually done by using anthropomorphic physical phantoms representing the human body. Due to such a challenge of having representative physical phantoms a virtual calibration has been introduced. The use of computational phantoms and Monte Carlo methods to simulate radiation transport have been demonstrated to be a worthy alternative, not only as a complementary calibration method but also as a powerful tool for the design and optimization of counting geometries. In this study we introduce a methodology for building a 3D human body library that spans variation in both subject shape and size. Open source codes as MakeHuman and Blender software packages have been used for the creation and modelling of 3D humanoid characters based on polygonal mesh surfaces. Also, a home-made software was developed whose main goal is to convert the binary 3D voxel grid into a MCNPX input file. This paper summarizes (1) the development of the MaMP and FeMP - Male and Female Mesh Phantoms, the two first mesh phantoms generated from a series of 3D human bodies library created at SCK-CEN and (2) presents a comparison between the counting efficiency results obtained from the simulations of both mesh phantoms using MCNPX code.