Results 181 to 190 of about 7,705 (226)

An electronic portal imaging device as a physics tool

Medical Dosimetry, 1997
An electronic portal imaging device (EPID) can be used not only to acquire megavoltage patient images but also to measure certain radiation beam parameters of the linear accelerator. EPID images can be used to verify field junctions, center of collimator rotation, or radiation vs. light field coincidence.
Ervin B Podgorsak
exaly   +3 more sources

Dosimetric characteristics of a liquid-filled electronic portal imaging device [PDF]

International Journal of Radiation Oncology*Biology*Physics, 1995
To determine the characteristics of a commercial electronic portal imaging device (EPID), based on a two-dimensional matrix of liquid-filled ionization chambers, for transmission dose measurements during patient treatment.Electronic portal imaging device measurements were performed in a cobalt-60 beam and two accelerator x-ray beams, and compared with ...
Van Herk, Marcel; id_orcid 0000-0001-6448-898X, Essers, M, Hoogervorst, B R, van Herk, M, Lanson, H, Mijnheer, B J   +5 more
openaire   +4 more sources

First clinical tests using a liquid-filled electronic portal imaging device and a convolution model for the verification of the midplane dose [PDF]

Radiotherapy and Oncology, 1998
BACKGROUND AND PURPOSE: Recently, algorithms have been developed to derive the patient dose from portal dose measurements using a liquid-filled electronic portal imaging device.
Ronald Boellaard, Marcel Van Herk, Ben Mijnheer   +2 more
exaly   +4 more sources

Verification of lung attenuator positioning before total body irradiation using an electronic portal imaging device [PDF]

International Journal of Radiation Oncology Biology Physics, 1993
PURPOSE: We report the first clinical experience with an electronic portal imaging device for lung attenuator positioning before delivery of total body irradiation.
David J Gladstone, Marcel Van Herk, L M Chin   +2 more
exaly   +5 more sources

Evaluation of an electronic portal imaging device (target view, ge) as a quality assurance tool [PDF]

Reports of Practical Oncology and Radiotherapy, 2001
PurposeA proper control of the geometrical accuracy of treated portals during radiotherapy results in higher quality of treatment and may lead to the increase in the therapeutic gain.In this work, an evaluation of an electronic portal imaging device ...
Piotr Milecki, Sergiusz Nawrocki, Julian Malicki   +2 more
exaly   +5 more sources

An electronic portal imaging device for transit dosimetry

Physics in Medicine and Biology, 1997
An electronic portal imaging device has been designed and constructed. It consists of an array of 128 CsI scintillation crystals coupled to photodiodes which is scanned across the field in 4 seconds. The linac is operated at a dose rate of 400 cGy min-1 and the dose delivered for image acquisition is approximately 27 cGy.
SymondsTayler, JRN, Partridge, M, Evans, PM   +2 more
openaire   +4 more sources

Use of electronic portal imaging devices for electron treatment verification

Australasian Physical & Engineering Sciences in Medicine, 2015
This study aims to help broaden the use of electronic portal imaging devices (EPIDs) for pre-treatment patient positioning verification, from photon-beam radiotherapy to photon- and electron-beam radiotherapy, by proposing and testing a method for acquiring clinically-useful EPID images of patient anatomy using electron beams, with a view to enabling ...
Kairn, T., Aland, T., Crowe, S. B., Trapp, J. V.   +3 more
openaire   +5 more sources

A method for controlling image acquisition in electronic portal imaging devices

Physics in Medicine and Biology, 2000
Certain types of camera-based electronic portal imaging devices (EPIDs) which initiate image acquisition based on sensing a change in video level have been observed to trigger unreliably at the beginning of dynamic multileaf collimation sequences. A simple, novel means of controlling image acquisition with an Elekta linear accelerator (Elekta Oncology ...
A G, Glendinning, S G, Hunt, D E, Bonnett   +2 more
openaire   +2 more sources

Assessment of flatness and symmetry of megavoltage x-ray beam with an electronic portal imaging device (EPID) [PDF]

Australasian Physical and Engineering Sciences in Medicine, 2002
Copyright © 2002 ACPSEM. All rights reserved. The document attached has been archived with permission from the publisher.The input/output characteristics of the Wellhofer BIS 710 electronic portal imaging device (EPID) have been investigated to establish
T Van Doorn, Eva Bezak, Bezak E
exaly   +3 more sources

Measurement possibilities using an electronic portal imaging device

Medical Dosimetry, 1993
A vital role in the quality control of radiotherapy is the use of portal imaging for verifying field size, shape, orientation and patient set-up. Coincidence of treated volume and target volume is imperative. Electronic portal imaging devices are effective at providing this verification.
M C, Kirby, P C, Williams
openaire   +2 more sources