نتایج جستجو برای: electronic portal imaging device radiation therapy

تعداد نتایج: 2055089  

2015
Charbel Merheb Clément Chevillard Wassim Ksouri Maher Fawzi Marc Bollet Alain Toledano

Several algorithms exist to perform quality assurance for volumetric-modulated arc therapy (VMAT) treatments based on electronic portal imaging devices (EPID). These algorithms are used to compare doses (convert into water, GLAaS) and fluences (in amorphous silicon (aSi), Varian portal dosimetry). The aim of this study is to compare the two methods using clinical data. In this study, Varian por...

2017
Baozhou Sun Jenghwa Chang Yi Rong

The field of radiotherapy (RT) has benefited substantially from advancements in Image-Guided Radiotherapy (IGRT) in the past 15 years. IGRT now constitutes the integration of a wide range of imaging technology with modern RT delivery systems that include 3D anatomical and functional-based imaging for tumor volume identification, 3D target volume localization, and motion management information f...

Journal: :Medical physics 2008
Philip Vial Peter B Greer Peter Hunt Lyn Oliver Clive Baldock

The purpose of this study was to experimentally quantify the change in response of an amorphous silicon (a-Si) electronic portal imaging device (EPID) to dynamic multileaf collimator (dMLC) beams with varying MLC-transmitted dose components and incorporate the response into a commercial treatment planning system (TPS) EPID prediction model. A combination of uniform intensity dMLC beams and stat...

2017
Gerben R. Borst

Purpose: Kilovoltage cone-beam computed tomography (CBCT) has been developed to provide accurate soft-tissue and bony setup information. We evaluated clinical CBCT setup data and compared CBCT measurements with electronic portal imaging device (EPID) images. Material and Methods: The setup error for CBCT scans at the treatment unit relative to the planning CT was measured for 62 patients (524 s...

Journal: :Tumori 2012
Francesco Deodato Savino Cilla Mariangela Massaccesi Gabriella Macchia Edy Ippolito Luciana Caravatta Vincenzo Picardi Michele Romanella Carlo Di Falco Alessandra Bartollino Vincenzo Valentini Numa Cellini Marco De Spirito Angelo Piermattei Alessio G Morganti

AIMS AND BACKGROUND The aim of this report was to investigate the feasibility in terms of treatment time prolongation of an on-line no-action level correction protocol, based on daily electronic portal image verification. METHODS AND STUDY DESIGN The occupation of a linear accelerator (LINAC) delivering 3-D conformal treatments was monitored for two weeks (from Monday to Friday, 10 working da...

2004
Chenyang Xu Xiaolei Huang Arun Krishnan Sanjiv Samant

Intensity Modulated Radiation Therapy (IMRT) is an innovative, three-dimensional conformal radiation treatment that can deliver highly focused and precisely shaped radiation to a tumor site through the use of the Multi-Leaf Collimators (MLC). A crucial step in IMRT procedure is the verification of MLC positioning to assure the accuracy of radiation treatment delivery. In this paper, we have dev...

Journal: :Physics in medicine and biology 2011
Youcef El-Mohri Larry E Antonuk Qihua Zhao Richard B Choroszucha Hao Jiang Langechuan Liu

Megavoltage, cone-beam computed tomography (MV CBCT) employing an electronic portal imaging device (EPID) is a highly promising technique for providing soft-tissue visualization in image-guided radiotherapy. However, current EPIDs based on active matrix flat-panel imagers (AMFPIs), which are regarded as the gold standard for portal imaging and referred to as conventional MV AMFPIs, require high...

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