نتایج جستجو برای: dose enhancement

تعداد نتایج: 433074  

Background: Normoxic type MAGICA gel dosimeters are established for dose quantification in three dimensions for radiotherapy. Objective(s): The ability of MAGICA polymer gel was assessed by experimental measurements method for studying the effect of gold nanoparticles (GNPs) in dose enhancement under the external 18MV radiotherapy practices. <...

ژورنال: سنجش و ایمنی پرتو 2017

Treatment of radio-sensitized tumor is one of the promising modalities in radiotherapy. Since the different parameters and physical conditions vary in the treatments, the use of simulation models is easier, less costly and faster than practical methods for forecasting the solutions designed to optimize treatment. Therefore in this study, Monte Carlo simulations are applied to investigate the do...

Introduction: Irradiation of loaded tumor with high-Z nanoparticles with low energy photon of 192Ir source during brachytherapy increases absorbed dose of tumor due to increase in possibility of photoelectric phenomena. Therefore, this study aimed to investigate dose enhancement due to nanoparticles (NPs) with different atomic numbers and concentrations as well as effect of NPs distribution (un...

Journal: :International Journal of Radiation Oncology*Biology*Physics 2018

2017
M.M. Firoozabadi Gh. Izadi Vasafi K. Karimi-sh

BACKGROUND In neutron interaction with matter and reduction of neutron energy due to multiple scatterings to the thermal energy range, increasing the probability of thermal neutron capture by neutron captures makes dose enhancement in the tumors loaded with these materials. OBJECTIVE The purpose of this study is to evaluate dose distribution in the presence of 10B, 157Gd and 33S neutron captu...

Aim: The aim of this study is to find an optimum material to protect garment for protection against 99Tcm radionuclide.Materials and Methods: Monte Carlo simulation code was applied to investigate radiation attenuation of 13 shielding materials including: Ba, gray Sn, white Sn, Sb, Bi, Bi2O3, BaSO4, Sn/W, Sb/W, Pb and W with thicknesses of 0.5 and 1 mm to determine an optimum protective garment...

Ali Yadollahpour, Mohammad Javad Tahmasebi Birgani Vahid Bayati Zohre Rezaee

Introduction: Radiation therapy (RT) is the gold standard treatment for more than half of known tumors. There is increasing evidence that combining radiation therapy with a radiosensitizer can enhance the efficiency of this treatment modality. A radiosensitizer preferably enhances dose at the site of tumor and increases discrimination between tumor and normal surrounding tissue...

Journal: :AJNR. American journal of neuroradiology 1994
K H Chang D G Ra M H Han S H Cha H D Kim M C Han

PURPOSE To compare the degree of MR contrast enhancement of 0.5 T and 2.0 T in various brain tumors. METHODS MR images were studied prospectively in each of 31 patients with brain tumors (11 gliomas, 6 meningiomas, 6 neurinomas, and 8 others) before and after intravenous injection of gadopentetate dimeglumine. In every patient, both 0.5-T and 2.0-T MR studies were done within 1 week. Each pat...

Arezoo Kazemzadeh Habiballah Moradi

Introduction: Radiotherapy plays a vital role in cancer treatment. To establish a new potency in radiosensitize tumor cells, delivery of High-Z materials is offered. To date, several simulation geometries have been applied to define simulation sets. The clustering of nanoparticles (NPs) within the cells is a prominent parameter usually ignored in simulation studies. <stro...

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