Results 111 to 120 of about 25,468 (231)

Performance optimization of the Varian aS500 EPID system

Journal of Applied Clinical Medical Physics, 2006
Today, electronic portal imaging devices (EPIDs) are widely used as a replacement to portal films for patient position verification, but the image quality is not always optimal. The general aim of this study was to optimize the acquisition parameters of an amorphous silicon EPID commercially available for clinical use in radiation therapy with the view
Berger, Lucie, François, Pascal, Gaboriaud, Geneviève, Rosenwald, Jean‐Claude   +3 more
openaire   +2 more sources

Sensitivity study of an automated system for daily patient QA using EPID exit dose images

Journal of Applied Clinical Medical Physics, 2018
The dosimetric consequences of errors in patient setup or beam delivery and anatomical changes are not readily known. A new product, PerFRACTION (Sun Nuclear Corporation), is designed to identify these errors by comparing the exit dose image measured on ...
A. H. Zhuang, A. Olch
semanticscholar   +1 more source

Comparison of forward- and back-projection in vivo EPID dosimetry for VMAT treatment of the prostate

Physics in Medicine and Biology, 2018
In the forward-projection method of portal dosimetry for volumetric modulated arc therapy (VMAT), the integrated signal at the electronic portal imaging device (EPID) is predicted at the time of treatment planning, against which the measured integrated ...
J. Bedford, I. Hanson, V. Hansen
semanticscholar   +1 more source

Multi-parametric Improvements in the CCD Camera-based EPID for Portal Dosimetry

Journal of Medical Signals and Sensors, 2017
Dosimetric verification of radiation treatment has recently been extended by the introduction of electronic portal imaging devices (EPIDs). Detailed dose response specifications of EPID should be addressed prior to any dosimetric application. The present
Vahideh Nazari, Seied R Mahdavi, Ahmad Mostaar, Hassan Nedaei, Mohammad A Mosleh Shirazi, Alireza Nikoofar, Golbarg Esmailie   +6 more
doaj  

Creating A Dynamic, Multi-Purpose Correction for Multiple Geometries and Field Sizes to Account for Off-Axis and Asymmetric Backscatter With Varian Portal Dosimetry

, 2016
Intensity modulated radiation therapy and volumetric modulated arc therapy are increasingly common in radiation therapy due to their benefits of target conformity and normal tissue sparing.
Manigold, Remy
core   +1 more source

An evolutionarily diverged CCD4 enzyme negatively regulates mesocotyl elongation in rice

New Phytologist, Volume 249, Issue 4, Page 1569-1579, February 2026.
Yasha Zhang, Abdugaffor Ablazov, Aparna Balakrishna, Chakravarthy Rajan, Yagiz Alagoz, Kit Xi Liew, Lamis Berqdar, Jian You Wang, Ikram Blilou, Xiongjie Zheng, Salim Al‐Babili   +10 more
wiley   +1 more source

Evaluation of interfraction setup variations for postmastectomy radiation therapy using EPID‐based in vivo dosimetry

Journal of Applied Clinical Medical Physics, 2019
Postmastectomy radiation therapy is technically difficult and can be considered one of the most complex techniques concerning patient setup reproducibility. Slight patient setup variations — particularly when high‐conformal treatment techniques are used —
Shengwei Kang, Jie Li, Jiabao Ma, Wei Zhang, X. Liao, H. Qing, T. Tan, X. Xin, B. Tang, A. Piermattei, L. Orlandini   +10 more
semanticscholar   +1 more source

Magneto-optical study of magnetic flux penetration into a current-carrying high-temperature superconductor strip

, 1999
Magnetic flux distribution across a high-temperature superconductor strip is measured using magneto-optical imaging at 15 K. Both the current-carrying state and the remanent state after transport current are studied up to the currents 0.97 Ic where Ic is
Baziljevich, M., Bobyl, A. V., Bratsberg, H., Gaevski, M. E., Galperin, Y. M., Johansen, T. H., Karmanenko, S. F., Shantsev, D. V.   +7 more
core   +1 more source

EPID dosimetry – configuration and pre-treatment IMRT verification

Reports of Practical Oncology & Radiotherapy, 2007
SummaryBackgroundThe electronic portal imaging device (EPID) is used for patient setup during radiotherapy sessions. Dosimetric verification is done using ion chambers, diodes and thermoluminescence detectors. In intensity-modulated radiation therapy (IMRT) the dosimetry is a sophisticated and time-consuming task.
Grządziel, Aleksandra, Smolińska, Barbara, Rutkowski, Roman, Ślosarek, Krzysztof   +3 more
openaire   +1 more source

The diffusion of fertilizer in Ethiopia: pattern determinants and implications [PDF]

, 1979
African Studies Center Working Paper No ...
Aklilu, Bisrat
core