Absorbed fractions in a voxel‐based phantom calculated with the MCNP‐4B code

Abstract

A new approach for calculating internal dose estimates was developed through the use of a more realistic computational model of the human body. The present technique shows the capability to build a patient-specific phantom with tomography data (a voxel-based phantom) for the simulation of radiation transport and energy deposition using Monte Carlo methods such as in the MCNP-4B code. MCNP-4B absorbed fractions for photons in the mathematical phantom of Snyder et al. agreed well with reference values. Results obtained through radiation transport simulation in the voxel-based phantom, in general, agreed well with reference values. Considerable discrepancies, however, were found in some cases due to two major causes: differences in the organ masses between the phantoms and the occurrence of organ overlap in the voxel-based phantom, which is not considered in the mathematical phantom.

3-D dose distributions for optimum radiation treatment planning of complex foods

“…A series of X-ray beams from different angles are used to create cross sectional images of the target. This technique has been widely used in the medical field for dosimetry planning and analysis in radiotherapy (DeMarco, Solberg, & Smathers, 1998;Yoriyaz & Santos, 2000). When food samples are scanned by a CT scanner, multi-sliced CT data are obtained and each pixel on the slice image is assigned a numerical value, e.g., fat ranges from À200 to À5, water from À5 to 5, which is related to the densities of scanned materials (food composition).…”

Effect of Patient Morphology on Dosimetric Calculations for Internal Irradiation as Assessed by Comparisons of Monte Carlo Versus Conventional Methodologies

“…Patient-specific Monte Carlo-based dosimetric methodologies have been investigated by several groups (14)(15)(16)(17). These methods have been proposed as being the most accurate, incorporating minimal assumptions because S factors can be calculated for each patient, taking into account both the morphology of the radionuclide and its physical properties.…”

The Development of the α-Particle Emitting Radionuclides 212Bi and 213Bi, and Their Decay Chain Related Radionuclides, for Therapeutic Applications

“…Doses to tumor and organs were calculated according to the MIRD formalism aided by Monte Carlo simulations of particle histories. 126 Tumor volume multiplication times versus dose of s.c. tumors of 100-200 mg (approximately 6 mm) was measured. A linear relationship from 1 to 2 Gy and upward was found for 213 Bi.…”