background: gold nanoparticles (gnps) have been shown as a good radiosensitizer. in combination with radiotherapy, several studies with orthovoltage x-rays have shown considerable dose enhancement effects. this paper reports the dose enhancement factor (def) due to gnps in 18 megavoltage (mv) beams. materials and methods: different geometrical 50-nm gnps configurations at a concentration of 5 m...

background: exposure conditions in ct examinations are quite different from conventional xray. in ct examination higher dose is given to patient in comparison with the dose in other diagnostic examinations. in order to calculate organ effective dose in chest ct, monte carlo simulation has been used in this study. materials and methods: the impact survey data were used to determine the parameter...

BACKGROUND Although Monte Carlo simulations of light propagation in full segmented three-dimensional MRI based anatomical models of the human head have been reported in many articles. To our knowledge, there is no patient-oriented simulation for individualized calibration with NIRS measurement. Thus, we offer an approach for brain modeling based on image segmentation process with in vivo MRI T1...

Introduction: Recently, an approach exploiting the proton therapy biological enhancement by using Boron atoms injected inside a tumor, has been proposed. Three alpha particles with an average energy around 4MeV are emitted from the point of reaction between a proton and boron. In addition, the 719 keV prompt gamma emitted by the proton Boron fusion reactions can be used for on-...

Background: The dosimetric parameters required in lung cancer radiation therapy are taken from a homogeneous water phantom; however, during treatment, the expected results are being affected because of its inhomogeneity. Therefore, it becomes necessary to quantify these deviations.Objective: The present study has been undertaken to find out inter- and intra- lung density variations and its dosi...

Boron Neutron Capture Therapy (BNCT) is a relatively safer technology for killing cancer cells, one of which the Glioblastoma multiforme. One main components BNCT equipment collimator functions as an exit point epithermal neutron particles that hit cells. In addition to experimental method, research can be carried out by modeling, including using MCNPX software based on Monte Carlo Method. This...

Background: For an effective treatment planning in brachytherapy, it is necessary to know the accurate source dosimetric information such as air kerma strength, exposure rate constant, dose rate constant and redial dose distribution. The usual method to determine these factors is thermo luminescent dosimeter (TLD) dosimetry. Nowadays, another more accurate method is known to be the Monte Carlo ...

Objective: Brachytherapy sources are widely used for the treatment of cancer. The report of Task Group No. 43 (TG-43) of American Association of Physicists in Medicine is known as the most common method for the determination of dosimetric parameters for brachytherapy sources. The aim of this study is to obtain TG-43 dosimetric parameters for 60Co, 137Cs, 192Ir and 103Pd brachyt...