نتایج جستجو برای: 6mv photon beam

تعداد نتایج: 178721  

2015
Christopher F. Njeh

Dose inhomogeneity in treatment planning can be compensated using physical wedges. Enhanced dynamic wedges (EDW) were introduced by Varian to overcome some of the shortcomings of physical wedges. The objectives of this study were to measure EDW output factors for 6 MV and 20 MV photon energies for a Varian 2300CD. Secondly, to review the literature in terms of published enhanced dynamic wedge o...

Journal: :iranian journal of radiation research 0
gh. geraily department of medical physics, tehran university of medical science, tehran, iran m. mirzapour department of electronic, east tehran branch, islamic azad university, tehran, iran s.r. mahdavi department of medical physics, tehran university of medical science, tehran, iran m. allahverdi department of medical physics, tehran university of medical science, tehran, iran a. mostaar department of biomedical engineering and medical physics, shahid beheshti university of medical science, tehran, iran m. masoudifar department of radiation oncology, mahak hospital, tehran, iran

background: physical wedges are still widely used as beam modifiers in external beam radiotherapy. however the presence of them in the beam trace may cause beam hardening which may not be considered in many treatment planning systems. the aim of this study is to investigate the beam hardening effect generated by physical wedges via different beam quality indexes as photon spectrum, half value l...

2006
M. Dinesh Kumar N. Thirumavalavan D. Venugopal Krishna M. Babaiah

To evaluate the utility of Dynalog file information for planar dose verification in IMRT QA, a program is developed to convert Dynalog file data to DMLC field files. For this study, five predefined fluencies are planned and delivered using Varian, Eclipse 3D planning system and 6MV photon beam of Varian, Clinac DMX linear accelerator. To measure planar dose distribution, Kodak, EDR2 films are e...

Journal: :Medical physics 2012
M Mera L Pereira E Meilán F Del Moral A Teijeiro M Salgado B Andrade F Gomez V Fuentes-Vázquez J Caruncho A Medina

PURPOSE The most common material for shielding is concrete, which can be made using various materials of different densities as aggregates. New techniques in radiotherapy, as IMRT and VMAT, require more monitor units and it is important to develop specifically designed shielding materials. METHODS Arraela S.L. has developed new concrete (CONTEK®-RFH2), which is made from an arid with a high p...

  Abstract   Background : Beam-hardening artifacts in CT image set of patient with a hip prosthesis cause difference between dose distributions resulted by treatment planning system (TPS) algorithms and actual dose distribution in patient body. In this study, dose distributions of TPS algorithms were compared with the results of Monte Carlo simulations of Titanium and Steal as a h...

2017
Vasanthan Sakthivel Ganesh Kadirampatti Mani Sunil Mani Raghavendiran Boopathy

The purpose of this paper is to provide data on development of second primary cancers within or adjacent to tissue irradiated in the treatment of primary head and neck cancers using different techniques and modalities. Materials and methods: We selected five patients with HandN tumors located in base of the tongue for risk assessment. In order to examine the impact of choices of various plannin...

Akram Astani Mohammad hosein Zare Nouraddin Abdi Goushbolagh

Introduction: Recently Cerium oxide nanoparticles (CONPs) are being checked as interventional treatments in biological systems. The scavenging of free radicals by nanoparticles performance is the inhibition of Reactive Oxygen Species (ROS). Ionizing radiations can prevent the proliferation and differentiation of cells and even cause apoptosis. CONPs, as radioprotection, can pro...

A. Mostaar, Gh. Geraily, M. Allahverdi, M. Masoudifar, M. Mirzapour, S.R. Mahdavi,

Background: Physical wedges are still widely used as beam modifiers in external beam radiotherapy. However the presence of them in the beam trace may cause beam hardening which may not be considered in many treatment planning systems. The aim of this study is to investigate the beam hardening effect generated by physical wedges via different beam quality indexes as photon spectrum, half value l...

Journal: :journal of paramedical sciences 0
danial seifi makrani department of medical physics, faculty of medical sciences, semnan university of medical sciences, semnan, iran hadi hasanzadeh cancer research center, department of medical physics, semnan university of medical sciences, semnan, iran tayyeb allahverdi pourfallah department of biochemistry and biophysics, faculty of medicine, mazandaran university of medical sciences, sari, iran arash ghasemi department of radiology and radiation oncology, faculty of medicine, mazandaran university of medical sciences, sari, iran majid jadidi department of medical physics, faculty of medical sciences, semnan university of medical sciences, semnan, iran hamed babapour guilan oncology center (goc), rasht, iran

the monte carlo method can be used to describe any technique that approximates solutions to quantitative problems through statistical sampling. this method is considered to be the most accurate method for dose calculation in radiotherapy. for complete modeling of a linear accelerator, it is required that the manufactured information covers all data, but some data such as primary electron energy...

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