نتایج جستجو برای: cerrobend

تعداد نتایج: 40  

2015
A. R. Farajollahi F. Bouzarjomehri M. Kiani

INTRODUCTION In radiation therapy centers across Iran, protection of normal tissues is usually accomplished by either Cerrobend or lead block shielding. In this study, the influence of these two shielding methods on central axis dose distribution of photon beam a Cobalt unit was investigated in clinical conditions. MATERIALS AND METHODS All measurements were performed for 60Co γ-ray beams and...

2015
Cristina Di Venanzio Marco Marinelli Alessia Tonnetti Gianluca Verona‐Rinati Paolo Bagalà Maria Daniela Falco Antonio Stefano Guerra Maria Pimpinella

The purpose of this study was to compare the dosimetric properties of small field electron beams shaped by circular Cerrobend blocks and stainless steel tubular applicators. Percentage depth dose curves, beam profiles, and output factors of small-size circular fields from 2 to 5 cm diameter, obtained either by tubular applicators and Cerrobend blocks, were measured for 6, 10, and 15 MeV electro...

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: :Medical physics 2016
N Lamichhane M Studenski

PURPOSE It is essential to assess the lung dose during TBI to reduce toxicity. Here we characterize the accuracy of the AAA and Acuros algorithms when using cerrobend lung shielding blocks at an extended distance for TBI. METHODS We positioned a 30×30×30 cm3 solid water slab phantom at 400 cm SSD and measured PDDs (Exradin A12 and PTW parallel plate ion chambers). A 2 cm thick, 10×10 cm2 cerr...

Introduction: Protecting the vital organs in radiation therapy is one of the most important issues. Cerrobend alloy, the most common material used as the shield, is melted several times and used for different patients. In this study changes in attenuation coefficient of cerrobend due to melting was investigated.   Materials and Methods: In melting furnace, ...

A R Farajollahi, F Bouzarjomehri M Kiani,

Introduction: In radiation therapy centers across Iran, protection of normal tissues is usually accomplished by either Cerrobend or lead block shielding. In this study, the influence of these two shielding methods on central axis dose distribution of photon beam a Cobalt unit was investigated in clinical conditions. Materials and Methods: All measurements were performed for 60Co γ-ray beams an...

Journal: :Journal of Cancer Research and Therapeutics 2016

2011
B. M. Wenig C. S. Heffess C. F. Adair Lippincott Williams

Thyroid cancer’s overall contribution to the worldwide cancer burden is relatively small, but incidence rates have increased over the last three decades throughout the world. This trend has been hypothesised to reflect a combination of technological advances enabling increased detection, but also changes in environmental factors, including population exposure to ionising radiation from fallout,...

A. Taherkhani, M. Mohammadi, M.S. Saboori, V. Changizi,

Background: In Radiation Therapy, the sparing of normal tissues can be performed using either multi-leaf collimators or Cerrobend blocks. The current work focuses on the physical characteristics of Cerrobend blocks including attenuation coefficient, effective penumbra width and isodose curves undulation in penumbral regions. Materials and Methods: All measurements were performed using ...

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