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Patient QA systems for rotational radiation therapy : A comparative experimental study with intentional errors

Fredh, Anna ; Scherman, Jonas Bengtsson ; Fog, Lotte S. and Munck Af Rosenschöld, Per LU orcid (2013) In Medical Physics 40(3).
Abstract

Purpose: The purpose of the present study was to investigate the ability of commercial patient quality assurance (QA) systems to detect linear accelerator-related errors. Methods: Four measuring systems (Delta , OCTAVIUS®, COMPASS, and Epiqa™) designed for patient specific quality assurance for rotational radiation therapy were compared by measuring four clinical rotational intensity modulated radiation therapy plans as well as plans with introduced intentional errors. The intentional errors included increasing the number of monitor units, widening of the MLC banks, and rotation of the collimator. The measurements were analyzed using the inherent gamma evaluation with 2% and 2 mm criteria and 3% and 3 mm criteria. When... (More)

Purpose: The purpose of the present study was to investigate the ability of commercial patient quality assurance (QA) systems to detect linear accelerator-related errors. Methods: Four measuring systems (Delta , OCTAVIUS®, COMPASS, and Epiqa™) designed for patient specific quality assurance for rotational radiation therapy were compared by measuring four clinical rotational intensity modulated radiation therapy plans as well as plans with introduced intentional errors. The intentional errors included increasing the number of monitor units, widening of the MLC banks, and rotation of the collimator. The measurements were analyzed using the inherent gamma evaluation with 2% and 2 mm criteria and 3% and 3 mm criteria. When applicable, the plans with intentional errors were compared with the original plans both by 3D gamma evaluation and by inspecting the dose volume histograms produced by the systems. Results: There was considerable variation in the type of errors that the various systems detected; the failure rate for the plans with errors varied between 0% and 72%. When using 2% and 2 mm criteria and 95% as a pass rate the Delta detected 15 of 20 errors, OCTAVIUS® detected 8 of 20 errors, COMPASS detected 8 of 20 errors, and Epiqa™ detected 20 of 20 errors. It was also found that the calibration and measuring procedure could benefit from improvements for some of the patient QA systems. Conclusions: The various systems can detect various errors and the sensitivity to the introduced errors depends on the plan. There was poor correlation between the gamma evaluation pass rates of the QA procedures and the deviations observed in the dose volume histograms.

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Please use this url to cite or link to this publication:
author
; ; and
publishing date
type
Contribution to journal
publication status
published
subject
in
Medical Physics
volume
40
issue
3
article number
031716
publisher
American Association of Physicists in Medicine
external identifiers
  • pmid:23464311
  • scopus:84874780814
ISSN
0094-2405
DOI
10.1118/1.4788645
language
English
LU publication?
no
id
733aebe2-5bf3-4ef3-bb1c-c2e44fc5e6b9
date added to LUP
2023-07-19 17:13:06
date last changed
2024-04-20 00:48:29
@article{733aebe2-5bf3-4ef3-bb1c-c2e44fc5e6b9,
  abstract     = {{<p>Purpose: The purpose of the present study was to investigate the ability of commercial patient quality assurance (QA) systems to detect linear accelerator-related errors. Methods: Four measuring systems (Delta <sup>4®</sup>, OCTAVIUS®, COMPASS, and Epiqa™) designed for patient specific quality assurance for rotational radiation therapy were compared by measuring four clinical rotational intensity modulated radiation therapy plans as well as plans with introduced intentional errors. The intentional errors included increasing the number of monitor units, widening of the MLC banks, and rotation of the collimator. The measurements were analyzed using the inherent gamma evaluation with 2% and 2 mm criteria and 3% and 3 mm criteria. When applicable, the plans with intentional errors were compared with the original plans both by 3D gamma evaluation and by inspecting the dose volume histograms produced by the systems. Results: There was considerable variation in the type of errors that the various systems detected; the failure rate for the plans with errors varied between 0% and 72%. When using 2% and 2 mm criteria and 95% as a pass rate the Delta<sup>4®</sup> detected 15 of 20 errors, OCTAVIUS® detected 8 of 20 errors, COMPASS detected 8 of 20 errors, and Epiqa™ detected 20 of 20 errors. It was also found that the calibration and measuring procedure could benefit from improvements for some of the patient QA systems. Conclusions: The various systems can detect various errors and the sensitivity to the introduced errors depends on the plan. There was poor correlation between the gamma evaluation pass rates of the QA procedures and the deviations observed in the dose volume histograms.</p>}},
  author       = {{Fredh, Anna and Scherman, Jonas Bengtsson and Fog, Lotte S. and Munck Af Rosenschöld, Per}},
  issn         = {{0094-2405}},
  language     = {{eng}},
  number       = {{3}},
  publisher    = {{American Association of Physicists in Medicine}},
  series       = {{Medical Physics}},
  title        = {{Patient QA systems for rotational radiation therapy : A comparative experimental study with intentional errors}},
  url          = {{http://dx.doi.org/10.1118/1.4788645}},
  doi          = {{10.1118/1.4788645}},
  volume       = {{40}},
  year         = {{2013}},
}