The aim of this study was to characterize electron contamination a flattened (FF) and an unflattened (FFF) Varian Clinac iX 6X 15X photon beams using Monte Carlo (MC) simulation. EGSnrc MC technique used model the head simulate dose distribution FF FFF beam in water phantom. materials geometrical data linac were provided by Tan Tock Seng Hospital (TTSH) Singapore. modeled removing flattening fi...

Introduction Superficial X-ray therapy is one of the most important treatment methods in radiotherapy especially in the treatment of superficial skin lesions (Up to 300 kVp). Quality of the X-ray beam that can be expressed by Half-Value Layer (HVL), are important indices for this type of treatment effective energy of photon and Homogeneity Coefficient (HC). Materials and Methods The HC of the s...

This study presents the results of EGSnrc Monte Carlo calculations of the dose distribution surrounding a high dose rate Yb brachytherapy source and 14 high dose rate and pulsed dose rate Ir brachytherapy sources. Energy-weighted spectra of emitted photons, a full set of TG-43 dosimetry parameters, along-away dose tables, and a description of the materials and geometry used for each source are ...

BACKGROUND HDR brachytherapy is one of the commonest methods of nasopharyngeal cancer treatment. In this method, depending on how advanced one tumor is, 2 to 6 Gy dose as intracavitary brachytherapy is prescribed. Due to high dose rate and tumor location, accuracy evaluation of treatment planning system (TPS) is particularly important. Common methods used in TPS dosimetry are based on computati...

Objective: Modelling linear accelerator (linac) photon beams using the Monte Carlo (MC) technique is presently most precise with which to calculate radiotherapy beam data. Complicated treatment plans can be achieved by Agility multileaf collimator. The focus of this study model a linac, integrated an head, EGSnrc MC code and investigate its accuracy compared actual measurements. Methodology: A ...

A systematic analysis of the available data has been carried out for mass energy-absorption coefficients and their ratios for air, graphite and water for photon energies between 1 keV and 2 MeV, using representative kilovoltage x-ray spectra for mammography and diagnostic radiology below 100 kV, and for ¹⁹²Ir and ⁶⁰Co gamma-ray spectra. The aim of this work was to establish 'an envelope of unce...

Several updated Monte Carlo (MC) codes are available to perform calculations of voxel S values for radionuclide targeted therapy. The aim of this work is to analyze the differences in the calculations obtained by different MC codes and their impact on absorbed dose evaluations performed by voxel dosimetry. Voxel S values for monoenergetic sources (electrons and photons) and different radionucli...