Human anatomical models have been indispensable to radiation protection dosimetry using Monte Carlo calculations. Existing MIRD-based mathematical models are easy to compute and standardize, but they are simplified and crude compared to human anatomy. This article describes the development of an image-based whole-body model, called VIP-Man, using transversal color photographic images obtained f...

Materials with high atomic numbers favor the occurrence of the photoelectric effect when they are irradiated with gamma rays. Therefore, the photoelectric effects of metal implants within the target regions in Gamma Knife Radiosurgery are worth studying. In the present work, Monte Carlo simulations using EGS4 were employed to investigate the resulting dose enhancements. A dose enhancement as hi...

The longitudinal and lateral shower profiles for 500 MeV electrons in iron are studied using dosimetry and activation techniques. The results are compared with Monte Carlo simulations and other previously published data. The agreement between the data and the EGS4 simulation results is good; a simple shower profile parametrization of type kz exp (−βz) does not represent the experimental data we...

The accuracy of the dose planning system (Leksell GammaPlan), used in Gamma Knife (type B) radiosurgery at extreme irradiation depths, was verified using the Monte Carlo technique. EGS4 Monte Carlo calculations were employed to calculate the dose distribution along the x, y and z axes for an irradiation relatively shallow in a spherical bony cavity water phantom. Two different sizes of the coll...

According as the progress of medical technique, X-ray imaging systems have been progressed. Especially, X-ray CT imaging system have been improved and widely used as general diagnostic methods nowadays in Japan. However, the doses for patients of X-ray CT imaging are relatively higher than of other Xray examinations. The dose estimations and optimizations on X-ray CT are very important for medi...

The high efficiency of the BGO detectors makes them very attractive candidates to replace NaI(T1) detectors, which are widely used in studies of body composition. In this work, the response functions of the BGO and NaI(T1) detectors were determined at 0.662,4.4, and 10.0 MeV using three different Monte Carlo codes: EGS4,l MCNP,2 and PHOTON.3 These codes differ in their input files and transport...

Occasionally, head and neck cancer patients treated with high-energy X-rays and gamma rays have titanium dental implants. The aim of this study was to calculate alterations in the irradiated bone caused by a foreign body, representing a titanium implant in size and physical qualities, using a stochastic (Monte Carlo) simulation. A clinical linear accelerator was simulated using BEAM/EGS4. The c...