نتایج جستجو برای: percent depth dose

تعداد نتایج: 559005  

Introduction: Radiation therapy using electron beams is a promising method due to its physical dose distribution. Monte Carlo (MC) code is the best and most accurate technique for forespeaking the distribution of dose in radiation treatment of patients.Materials and Methods: We report an MC simulation of a linac head and depth dose on central axis, along with profile calculations. The purpose o...

Journal: :iranian journal of medical physics 0
hamid-reza sadoughi medical physics research center, medical physics department, faculty of medicine, mashhad university of medical sciences, mashhad, iran shahrokh nasseri medical physics research center, medical physics department, faculty of medicine, mashhad university of medical sciences, mashhad, iran mahdi momennezhad medical physics research center, medical physics department, faculty of medicine, mashhad university of medical sciences, mashhad, iran imam reza hospital, mashhad university of medical sciences, mashhad, iran hadi sadoghi-yazdi department of computer engineering, ferdowsi university of mashhad, mashhad, mohammad-hossein bahreyni-toosi medical physics research center, medical physics department, faculty of medicine, mashhad university of medical sciences, mashhad, iran

introduction relative dose computation is a necessary step in radiation treatment planning. therefore, finding an approach that is both fast and accurate seems to be necessary. the purpose of this work was to investigate the feasibility of natural cubic spline to reconstruct dose maps for linear accelerator radiation treatment fields in comparison with those of the simulation. materials and met...

2015
Robert A. Corns Vicky W. Huang Steven D. Thomas

Flattening filter-free radiation beams have higher dose rates that significantly increase the ion recombination rate in an ion chamber's volume and lower the signal read by the chamber-electrometer pair. The ion collection efficiency correction (P(ion)) accounts for the loss of signal and subsequently changes dosimetric quantities when applied. We seek to characterize the changes to the percent...

2015
Vikren Sarkar Brian Wang Hui Zhao Bart Lynch Joshua A. James Kiernan T. McCullough Bill J. Salter

As very small ion chambers become commercially available, medical physicists may be inclined to use them during the linear accelerator commissioning process to better characterize the beam in steep dose gradient areas. For this work, a total of eight different ion chambers (volumes from 0.007 cc to 0.6 cc) and four different scanning systems were used to scan PDDs at both +300V and -300V biases...

Introduction Relative dose computation is a necessary step in radiation treatment planning. Therefore, finding an approach that is both fast and accurate seems to be necessary. The purpose of this work was to investigate the feasibility of natural cubic spline to reconstruct dose maps for linear accelerator radiation treatment fields in comparison with those of the simulation. Materials and Met...

Journal: :iranian journal of radiation research 0
y.l. kim department of radiology, choonhae college of health science, ulsan 689-784, south korea t.s. suh department of radiology, choonhae college of health science, ulsan 689-784, south korea b.y. choe department of radiology, choonhae college of health science, ulsan 689-784, south korea b.o. choi department of radiation oncology, seoul st. mary’s hospital, the catholic university, seoul 137-701, south korea j.b. chung department of radiadion oncology, seoul national university bundang hospital, seongnam 463-707, south korea j.w. lee department of radiation oncology, konkuk university medical center, seoul 143-729, south korea

background: dose calculation algorithms play a very important role in predicting the explicit dose distribution. we evaluated the percent depth dose (pdd), lateral depth dose profile, and surface dose volume histogram in inhomogeneous media using calculation algorithms and inhomogeneity correction methods. materials and methods: the homogeneous and inhomogeneous virtual slab phantoms used in th...

Abolfzal Nickfarjam Daniel Markel, Mahdieh Afkhami Ardakani Milad Najafzadeh, Mohammad Haghparast Mojtaba Hoseini-Ghahfarokhi,

Introduction: The aim of this study was to investigate the initial electron beam parameters for Monte Carlo model of 6MV photon beam produced by Siemens Oncor® linear accelerator.   Materials and Methods: In this study, the EGSnrc Monte Carlo user codes BEAMnrc and DOSXYZnrc were used. The beamnrc code were used for modelling of a 6 MV photon beam produced by...

B.M. Park, B.O. Choi, B.Y. Choe, J.B. Chung, J.W. Lee, J.Y. Jung, T.S. Suh, Y.J. Shin, Y.K. Bae, Y.L. Kim,

Background: Dose calculation algorithms play a very important role in predicting the explicit dose distribution. We evaluated the percent depth dose (PDD), lateral depth dose profile, and surface dose volume histogram in inhomogeneous media using calculation algorithms and inhomogeneity correction methods. Materials and Methods: The homogeneous and inhomogeneous virtual slab phantoms used in th...

Journal: :Optics express 2005
L P Yaroslavsky J Campos M Espínola I Ideses

With the recent advancement in visualization devices over the last years, we are seeing a growing market for stereoscopic content. In order to convey 3D content by means of stereoscopic displays, one needs to transmit and display at least 2 points of view of the video content. This has profound implications on the resources required to transmit the content, as well as demands on the complexity ...

2015
Miao Zhang Meral Reyhan Leonard H. Kim

The purpose of this study was to evaluate proton depth dose perturbation caused by a radio-opaque hydrogel fiducial marker. Electronic proton stopping powers in the hydrogel were calculated for energies 0.5-250 MeV, and Monte Carlo simulations were generated of hydrogel vs. gold markers placed at various water phantom depths in a generic proton beam. Across the studied energy range, the gel/wat...

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