A comprehensive study of the mechanical performance of gantry, EPID and the MLC assembly in Elekta linacs during gantry rotation

P Rowshanfarzad, Hans Lynggaard Riis, S J Zimmermann, M A Ebert

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

OBJECTIVE: In radiotherapy treatments, it is crucial to monitor the performance of linear accelerator (linac) components, including gantry, collimation system and electronic portal imaging device (EPID) during arc deliveries. In this study, a simple EPID-based measurement method is suggested in conjunction with an algorithm to investigate the stability of these systems at various gantry angles with the aim of evaluating machine-related errors in treatments.

METHODS: The EPID sag, gantry sag, changes in source-to-detector distance (SDD), EPID and collimator skewness, EPID tilt and the sag in leaf bank assembly owing to linac rotation were separately investigated by acquisition of 37 EPID images of a simple phantom with 5 ball bearings at various gantry angles. A fast and robust software package was developed for automated analysis of the image data. Nine Elekta AB (Stockholm, Sweden) linacs of different models and number of years in service were investigated.

RESULTS: The average EPID sag was within 2 mm for all tested linacs. Some machines showed >1-mm gantry sag. Changes in the SDD values were within 1.3 cm. EPID skewness and tilt values were <1° in all machines. The maximum sag in multileaf collimator leaf bank assemblies was around 1 mm. A meaningful correlation was found between the age of the linacs and their mechanical performance. Conclusions and Advances in knowledge: The method and software developed in this study provide a simple tool for effective investigation of the behaviour of Elekta linac components with gantry rotation. Such a comprehensive study has been performed for the first time on Elekta machines.

OriginalsprogEngelsk
Artikelnummer20140581
TidsskriftBritish Journal of Radiology
Vol/bind88
Udgave nummer1051
Antal sider8
ISSN0007-1285
DOI
StatusUdgivet - 2015

Fingeraftryk

Equipment and Supplies

Citer dette

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title = "A comprehensive study of the mechanical performance of gantry, EPID and the MLC assembly in Elekta linacs during gantry rotation",
abstract = "OBJECTIVE: In radiotherapy treatments, it is crucial to monitor the performance of linear accelerator (linac) components, including gantry, collimation system and electronic portal imaging device (EPID) during arc deliveries. In this study, a simple EPID-based measurement method is suggested in conjunction with an algorithm to investigate the stability of these systems at various gantry angles with the aim of evaluating machine-related errors in treatments.METHODS: The EPID sag, gantry sag, changes in source-to-detector distance (SDD), EPID and collimator skewness, EPID tilt and the sag in leaf bank assembly owing to linac rotation were separately investigated by acquisition of 37 EPID images of a simple phantom with 5 ball bearings at various gantry angles. A fast and robust software package was developed for automated analysis of the image data. Nine Elekta AB (Stockholm, Sweden) linacs of different models and number of years in service were investigated.RESULTS: The average EPID sag was within 2 mm for all tested linacs. Some machines showed >1-mm gantry sag. Changes in the SDD values were within 1.3 cm. EPID skewness and tilt values were <1° in all machines. The maximum sag in multileaf collimator leaf bank assemblies was around 1 mm. A meaningful correlation was found between the age of the linacs and their mechanical performance. Conclusions and Advances in knowledge: The method and software developed in this study provide a simple tool for effective investigation of the behaviour of Elekta linac components with gantry rotation. Such a comprehensive study has been performed for the first time on Elekta machines.",
keywords = "Age Factors, Algorithms, Humans, Particle Accelerators, Phantoms, Imaging, Radiometry, Radiotherapy Dosage, Radiotherapy Planning, Computer-Assisted, Radiotherapy Setup Errors, Reproducibility of Results, Rotation",
author = "P Rowshanfarzad and {Lynggaard Riis}, Hans and Zimmermann, {S J} and Ebert, {M A}",
year = "2015",
doi = "10.1259/bjr.20140581",
language = "English",
volume = "88",
journal = "British Journal of Radiology",
issn = "0007-1285",
publisher = "British Institute of Radiology",
number = "1051",

}

A comprehensive study of the mechanical performance of gantry, EPID and the MLC assembly in Elekta linacs during gantry rotation. / Rowshanfarzad, P; Lynggaard Riis, Hans; Zimmermann, S J; Ebert, M A.

I: British Journal of Radiology, Bind 88, Nr. 1051, 20140581, 2015.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - A comprehensive study of the mechanical performance of gantry, EPID and the MLC assembly in Elekta linacs during gantry rotation

AU - Rowshanfarzad, P

AU - Lynggaard Riis, Hans

AU - Zimmermann, S J

AU - Ebert, M A

PY - 2015

Y1 - 2015

N2 - OBJECTIVE: In radiotherapy treatments, it is crucial to monitor the performance of linear accelerator (linac) components, including gantry, collimation system and electronic portal imaging device (EPID) during arc deliveries. In this study, a simple EPID-based measurement method is suggested in conjunction with an algorithm to investigate the stability of these systems at various gantry angles with the aim of evaluating machine-related errors in treatments.METHODS: The EPID sag, gantry sag, changes in source-to-detector distance (SDD), EPID and collimator skewness, EPID tilt and the sag in leaf bank assembly owing to linac rotation were separately investigated by acquisition of 37 EPID images of a simple phantom with 5 ball bearings at various gantry angles. A fast and robust software package was developed for automated analysis of the image data. Nine Elekta AB (Stockholm, Sweden) linacs of different models and number of years in service were investigated.RESULTS: The average EPID sag was within 2 mm for all tested linacs. Some machines showed >1-mm gantry sag. Changes in the SDD values were within 1.3 cm. EPID skewness and tilt values were <1° in all machines. The maximum sag in multileaf collimator leaf bank assemblies was around 1 mm. A meaningful correlation was found between the age of the linacs and their mechanical performance. Conclusions and Advances in knowledge: The method and software developed in this study provide a simple tool for effective investigation of the behaviour of Elekta linac components with gantry rotation. Such a comprehensive study has been performed for the first time on Elekta machines.

AB - OBJECTIVE: In radiotherapy treatments, it is crucial to monitor the performance of linear accelerator (linac) components, including gantry, collimation system and electronic portal imaging device (EPID) during arc deliveries. In this study, a simple EPID-based measurement method is suggested in conjunction with an algorithm to investigate the stability of these systems at various gantry angles with the aim of evaluating machine-related errors in treatments.METHODS: The EPID sag, gantry sag, changes in source-to-detector distance (SDD), EPID and collimator skewness, EPID tilt and the sag in leaf bank assembly owing to linac rotation were separately investigated by acquisition of 37 EPID images of a simple phantom with 5 ball bearings at various gantry angles. A fast and robust software package was developed for automated analysis of the image data. Nine Elekta AB (Stockholm, Sweden) linacs of different models and number of years in service were investigated.RESULTS: The average EPID sag was within 2 mm for all tested linacs. Some machines showed >1-mm gantry sag. Changes in the SDD values were within 1.3 cm. EPID skewness and tilt values were <1° in all machines. The maximum sag in multileaf collimator leaf bank assemblies was around 1 mm. A meaningful correlation was found between the age of the linacs and their mechanical performance. Conclusions and Advances in knowledge: The method and software developed in this study provide a simple tool for effective investigation of the behaviour of Elekta linac components with gantry rotation. Such a comprehensive study has been performed for the first time on Elekta machines.

KW - Age Factors

KW - Algorithms

KW - Humans

KW - Particle Accelerators

KW - Phantoms, Imaging

KW - Radiometry

KW - Radiotherapy Dosage

KW - Radiotherapy Planning, Computer-Assisted

KW - Radiotherapy Setup Errors

KW - Reproducibility of Results

KW - Rotation

U2 - 10.1259/bjr.20140581

DO - 10.1259/bjr.20140581

M3 - Journal article

VL - 88

JO - British Journal of Radiology

JF - British Journal of Radiology

SN - 0007-1285

IS - 1051

M1 - 20140581

ER -