introduction: in recent decades, several monte carlo codes have been introduced for research and medical applications. these methods provide both accurate and detailed calculation of particle transport from linear accelerators. the main drawback of monte carlo techniques is the extremely long computing time that is required in order to obtain a dose distribution with good statistical accuracy. ...

introduction : due to the importance of laser light penetration and propagation in biological tissues, many researchers have proposed several numerical methods such as monte carlo, finite element and green function methods. among them, the monte carlo method is an accurate method which can be applied for different tissues. however, because of its statistical nature, monte carlo simulation requi...

monte carlo methods designed base on stochastic reiterations and can be useful in uncertainty conditions. the purpose of this research was investigation of uncertainty to rank desertification indicators. in order to decrease uncertainty have been applied monte carlo reiterations for each value of indicator, if rank of xi is higher than rank of xk constantly. using multi dimension integrals the ...

Assessment of secondary particles in breast proton therapy by Monte Carlo simulation code using MCNPX

in this paper, we calculate electron and hole impactionization coefficients in in0.52al0.48as using a monte carlo modelwhich has two valleys and two bands for electrons and holesrespectively. also, we calculate multiplication factor for electronand hole initiated multiplication regimes and breakdown voltagein in0.52al0.48as pin avalanche photodiodes. to validate themodel, we compare our simulat...

background: to reduce the dose to normal tissues surrounding the treated breast, a uniform magnetic field was used within a humanoid phantom in breast radiotherapy. materials and methods: monte carlo simulations were performed with geant4, irradiating humanoid phantoms in a magnetic field. to reconstruct phantoms, computed tomography (ct) data slices of four patients were used for the monte car...

this paper proposes a hybrid method to find cumulative distribution function (cdf) of completion time of gert-type networks (gtn) which have no loop and have only exclusive-or nodes. proposed method is cre-ated by combining an analytical transformation with gaussian quadrature formula. also the combined crude monte carlo simulation and combined conditional monte carlo simulation are developed a...

BACKGROUND We present a simulation model that predicts U.S. breast cancer mortality trends from 1975 to 2000 and quantifies the impact of screening mammography and adjuvant therapy on these trends. This model was developed within the Cancer Intervention and Surveillance Network (CISNET) consortium. METHOD A Monte Carlo simulation is developed to generate the life history of individual breast ...

Background: To reduce the dose to normal tissues surrounding the treated breast, a uniform magnetic field was used within a humanoid phantom in breast radiotherapy. Materials and Methods: Monte Carlo simulations were performed with GEANT4, irradiating humanoid phantoms in a magnetic field. To reconstruct phantoms, computed tomography (CT) data slices of four patients were used for the Monte Car...

PURPOSE Both the AccuBoost D-shaped and round applicators have been dosimetrically characterized and clinically used to treat patients with breast cancer. While the round applicators provide conformal dose coverage, under certain clinical circumstances the breast skin dose may be higher than preferred. The purpose of this study was to modify the round applicators to minimize skin dose while not...