The CAD-Compatible VHP-Male Computational Phantom

Anatomically accurate and numerically efficient computational phantoms of humans are essential to characterizing the response of a body to a variety of electromagnetic, acoustic and other types of external stimuli. In conjunction with advances in numerical simulation techniques and computational hardware, these computational phantoms enable exploration of innovative and exciting applications, from medical diagnostic techniques and therapeutic treatments to new ways of on- and in-body communications. However, in order to provide realistic estimates through simulation, the model must represent the subject as closely as possible, necessitating that all relevant anatomical features are captured. If this is not accomplished, the model will misrepresent the true physical environment, and critical information will not be captured during the simulation. This work presents a model of a male subject based on the Visible Human Project dataset. Each component of the model is constructed of triangular surface elements, making it compatible with CAD packages and facilitating its use in simulations based on major numerical methodologies. A description of the model, the procedure used for its construction and a baseline simulation are presented together with future integration and augmentation ideas.

Monte Carlo study on the gold and gadolinium nanoparticles radio-sensitizer effect in the prostate 125I seeds radiotherapy

Monte Carlo and TL dosimetry applied to the characterization of 125I brachytherapy with a different design with other 125I seeds. In a water phantom, lattice configuration simulated with 125I seed in the center and 10 nm gold and gadolinium nan-particle filed voxels. This simulation conducted to the characterization of the nano-particles DEF in low energy and prostate tissue. To study of the prostate brachytherapy, a humanoid computational phantom developed by CT slices applied. KTMAN-2 computational phantom contains 29 organs and 19 skeletal regions and was produced from cross-sectional x-ray computed tomography (CT slices) images. The simulated seed was 125I seed having an average energy of 28.4 keV for photons, a half-life of 59.4 days. DEF factor in the seed radiation energy (28.4 keV) DEF factor was found to be two times higher for the gold nano-particles. It was revealed than gold-nano-particles posing Z about 1.24 times higher than gadolinium led to around 200% DEF increasing in the same conditions and the nano-particles size. It was concluded that in low energy sources brachytherapy, photoelectric is dominant in the presence of relative high element nanoparticles. This leads to a high dose increasing in some micro-meters and causes a dramatic dose gradient in the vicinity of a nano-particle. This dose gradient effectively kills the tumor cells in continuous low energy irradiation in the presence of a high Z material nano-scaled particle. Application of gold nano-particles in low energy brachytherapy is recommended.