This work validates the use of an amorphous-silicon, flat-panel electronic portal imaging device (a-Si EPID) for use as a gauge of patient or phantom radiological thickness, as an alternative to dosimetry. The response of the a-Si EPID is calibrated by adapting a technique previously applied to scanning liquid ion chamber EPIDs, and the stability, accuracy and reliability of this calibration ar...

Thoracic cancer treatment presents dosimetric difficulties due to respiratory motion and lung inhomogeneity. Monte Carlo and deformable image registration techniques have been proposed to be used in four-dimensional (4D) dose calculations to overcome the difficulties. This study validates the 4D Monte Carlo dosimetry with measurement, compares 4D dosimetry of different tumor sizes and tumor mot...

A software program, SpekCalc, is presented for the calculation of x-ray spectra from tungsten anode x-ray tubes. SpekCalc was designed primarily for use in a medical physics context, for both research and education purposes, but may also be of interest to those working with x-ray tubes in industry. Noteworthy is the particularly wide range of tube potentials (40-300 kVp) and anode angles (recom...

The Integral Quality Monitoring (IQM) System is a real-time beam output verifying system that validates the integrity and accuracy of patient treatment plan (TP) data during radiation treatment. The purpose of this study was to evaluate the sensitivity of the IQM to errors in segment using EGSnrc/BEAMnrc Monte Carlo (MC) codes. Sensitivity analysis (SA) techniques were applied to study the sign...

Technical developments in radiotherapy (RT) have created a need for systematic quality assurance (QA) to ensure that clinical institutions deliver prescribed radiation doses consistent with the requirements of clinical protocols. For QA, an ideal dose verification system should be independent of the treatment-planning system (TPS). This paper describes the development and reproducibility evalua...

Total skin electron irradiation (TSEI) is a complex technique which requires many nonstandard measurements and dosimetric procedures. The purpose of this work was to validate measured dosimetry data by Monte Carlo (MC) simulations using EGSnrc-based codes (BEAMnrc and DOSXYZnrc). Our MC simulations consisted of two major steps. In the first step, the incident electron beam parameters (energy sp...

the acceptance of the right project which leads to the realization of the set objectives is one of the most important issues in project-oriented companies. therefore, corporate managers prefer to work on those projects which ensures the achievement of goals such as increasing financial profits or being the top brands in their rivals market. the present  research aimed at introducing  a systemat...

the acceptance of the right project which leads to the realization of the set objectives is one of the most important issues in project-oriented companies. therefore, corporate managers prefer to work on those projects which ensures the achievement of goals such as increasing financial profits or being the top brands in their rivals market. the present  research aimed at introducing  a systemat...

background: field matching problems in abutting electron fields can be managed by using spoilers. objective: the aim of this study was to design a monte carlo framework for the assessment of spoiler application in abutting electron fields. methods: a siemens primus treatment head was simulated for a 5 mev electron beam using beamnrc and dosxyznrc, egsnrc user codes. validation of beam model was...

the determination of gyration radius is a strong research for configuration of a macromolecule. italso reflects molecular compactness shape. in this work, to characterize the behavior of theprotein, we observe quantities such as the radius of gyration and the average energy. we studiedthe changes of these factors as a function of temperature for acetylcholine receptor protein in gasphase with n...