نتایج جستجو برای: cerrobend blocks

تعداد نتایج: 77772  

2002
D. M. DIMITRIADIS

This study describes the importance of attenuator scatter in the construction of compensators. The attenuator used in this study was Lipowitz metal, commonly referred to as cerrobend. Linear attenuation coefficients of cerrobend were measured in air for different thickness of cerrobend sheets and different field sizes for a 6-MV photon beam. The magnitude of the dose contribution from photons s...

2017
F. Seif M.J. Tahmasebi-Birgani M.R. Bayatiani

BACKGROUND In this study, a method for linear attenuation coefficient calculation was introduced. METHODS Linear attenuation coefficient was calculated with a new method that base on the physics of interaction of photon with matter, mathematical calculation and x-ray spectrum consideration. The calculation was done for Cerrobend as a common radiotherapy modifier and Mercury. RESULTS The val...

Journal: :Journal of Cancer Research and Therapeutics 2016

A.R. Farajollahi, F. Bouzarjomehri, M. Kiani,

Background: The Shielding methods in radiotherapy due to delivering an accurate radiation dose to cancer tissues and avoiding unnecessary dose to normal tissues are very important. These methods include Lead standard blocks, individual molding and multi leaf collimator (MLC). The MLC method is not still common in Iran radiotherapy centers. Individual molding is better than the lead block shield...

Journal: :iranian journal of radiation research 0
f. bouzarjomehri shahid sadoughi university of medical sciences, yazd, iran m. kiani tabriz university of medical sciences, medical physics, tabriz, iran a.r. farajollahi tabriz university of medical sciences, medical physics, tabriz, iran

background: the shielding methods in radiotherapy due to delivering an accurate radiation dose to cancer tissues and avoiding unnecessary dose to normal tissues are very important. these methods include lead standard blocks, individual molding and multi leaf collimator (mlc). the mlc method is not still common in iran radiotherapy centers. individual molding is better than the lead block shield...

Introduction: The head scatter factor (Sc) is important to measurements radiation beam and beam modeling of treatment planning systems used for advanced radiation therapy techniques. This study aimed to investigate the design of a mini-phantom to measurement variations in collimator Sc in the presence of shielding blocks for shaping the beam using different field sizes. <str...

2016
Benjamin D. Rusk Robert L. Carver John P. Gibbons Kenneth R. Hogstrom

The purpose of this work was to evaluate differences in dose resulting from the use of copper aperture inserts compared to lead-alloy (Cerrobend) aperture inserts for electron beam therapy. Specifically, this study examines if copper aperture inserts can be used clinically with the same commissioning data measured using lead-alloy aperture inserts. The copper inserts were acquired from .decimal...

Journal: :Journal of Applied Clinical Medical Physics 2016

2008
Yaxi Liu Chengyu Shi Patricia Tynan Niko Papanikolaou

The purpose of the present work was to measure the performance characteristics in the penumbra region and on the leaf-end of an innovative dual-layer micro multileaf collimator (DmMLC). The DmMLC consists of two orthogonal (upper and lower) layers of leaves; a standard MLC consists of one layer. The DmMLC provides unique performance characteristics in smoothing dose undulation, reducing leaf-en...

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