<abstract xml:lang="en" xmlns="http://www.w3.org/1999/xhtml"><bold>Background.</bold> The purpose of the study was to verify different values of quality parameters of portal images in radiotherapy.<bold>Materials and methods.</bold> We investigated image qualities of different field verification systems. Four EPIDs (Siemens OptiVue500aSi®, Siemens BeamView Plus®, Elekta iView® and Varian PortalVision™) were investigated with the PTW EPID QC PHANTOM® and compared with two portal film systems (Kodak X-OMAT® cassette with Kodak X-OMAT V® film and Kodak EC-L Lightweight® cassette with Kodak Portal Localisation ReadyPack® film).<bold>Results.</bold> A comparison of the f50 and f25 values of the modulation transfer functions (MTFs) belonging to each of the systems revealed that the amorphous silicon EPIDs provided a slightly better high contrast resolution than the Kodak Portal Localisation ReadyPack® film with the EC-L Lightweight® cassette. The Kodak X-OMAT V® film gave a poor low contrast resolution: from the existing 27 holes only 9 were detectable.<bold>Conclusions.</bold> On the base of physical characteristics, measured in this work, the authors suggest the use of amorphous-silicon EPIDs producing the best image quality. Parameters of the EPIDs with scanning liquid ionisation chamber (SLIC) were very stable. The disadvantage of older versions of EPIDs like SLIC and VEPID is a poor DICOM implementation, and the modulation transfer function (MTF) values (f50 and f25) are less than that of aSi detectors.</abstract>

Background. The purpose of the study was to verify different values of quality parameters of portal images in radiotherapy.Materials and methods. We investigated image qualities of different field verification systems. Four EPIDs (Siemens OptiVue500aSi®, Siemens BeamView Plus®, Elekta iView® and Varian PortalVision™) were investigated with the PTW EPID QC PHANTOM® and compared with two portal film systems (Kodak X-OMAT® cassette with Kodak X-OMAT V® film and Kodak EC-L Lightweight® cassette with Kodak Portal Localisation ReadyPack® film).Results. A comparison of the f50 and f25 values of the modulation transfer functions (MTFs) belonging to each of the systems revealed that the amorphous silicon EPIDs provided a slightly better high contrast resolution than the Kodak Portal Localisation ReadyPack® film with the EC-L Lightweight® cassette. The Kodak X-OMAT V® film gave a poor low contrast resolution: from the existing 27 holes only 9 were detectable.Conclusions. On the base of physical characteristics, measured in this work, the authors suggest the use of amorphous-silicon EPIDs producing the best image quality. Parameters of the EPIDs with scanning liquid ionisation chamber (SLIC) were very stable. The disadvantage of older versions of EPIDs like SLIC and VEPID is a poor DICOM implementation, and the modulation transfer function (MTF) values (f50 and f25) are less than that of aSi detectors.

Verification of quality parameters for portal images in radiotherapy

Municipal Centre for Oncoradiology, Uzsoki Hospital, Budapest, Hungary

Institute of Nuclear Techniques, Budapest University of Technology and Economics, Budapest, Hungary

Radiology and Oncology

{"article-title":"Verification of quality parameters for portal images in radiotherapy"}

Background. The purpose of the study was to verify different values of quality parameters of portal images in radiotherapy.Materials and methods. We...

Verification of quality parameters for portal images in radiotherapy

Published Online: Dec 31, 2010

Page range: 68 - 74

DOI: https://doi.org/10.2478/v10019-010-0052-6

Keywords
electronic portal imaging device, quality control, portal film

This content is open access.

Verification of quality parameters for portal images in radiotherapy

Published Online: Dec 31, 2010

Page range: 68 - 74

DOI: https://doi.org/10.2478/v10019-010-0052-6

Keywordselectronic portal imaging device, quality control, portal film

This content is open access.

Keywords
electronic portal imaging device, quality control, portal film