CHAPTER 3
WHOLE BODY DOSIMETRY SIMULATIONS WITH THE UF-B SERIES PHANTOM
USING THE PENTRAN-MP CODE SYSTEM FOR LOW ENERGY PHOTONS
This work describes our 3-D SN Medical Physics code system PENTRAN-MP in support
of ongoing development research in large scale 3-D absorbed dose computationS42. In the
PENTRAN-MP code system, Figure 3-1, an initial high-resolution data phantom is obtained
from state of the art 3-D whole-body voxelized human phantoms based on Computed
Tomography (CT) images43. A pediatric patient (an 11-year-old male) 3-D CT image is then
down sampled (collapsed) into a coarser one. The collapsed model was cast into a 3-D spatial
distribution and sub-divided into coarse meshes containing fine meshes with constant densities.
SN calculations were performed using PENTRAN and Monte Carlo results were generated with
MCNP5. To accurately compare our deterministic results with the Monte Carlo, we also
generated an equivalent MCNP5 31 model implementing continuous energy ENDF/B-VI cross-
section data libraries. Post processing in the PENTRAN-MP code system includes seamless
parallel data extraction using the PENDATA code, followed by the application of the 3-D-DOSE
code to determine absorbed dose in each voxel of the 3-D phantom based on fitted mass-energy
absorption coefficients 44, hence yielding a whole-body absorbed dose distribution. This chapter
is presented as follows: Sections 3.1, 3.2 and 3.3 highlight the methodology for accomplishing
our deterministic calculations. Section 3.4 presents a computational human phantom example
implementing the methodology of PENTRAN-MP and an equivalent MCNP5 model. Section 3.5
compares the Monte Carlo and deterministic solutions and analyzes the parallel performance of
the PENTRAN. Finally, Section 3.6 discusses the findings of this Chapter.