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Acceptance tests and quality control (QC) procedures for the clinical implementation of intensity modulated radiotherapy (IMRT) using inverse planning and the sliding window technique : experience from five radiotherapy departments

Van Esch, Ann ; Bohsung, Jörg ; Sorvari, Pekka ; Tenhunen, Mikko ; Paiusco, Marta ; Iori, Mauro ; Engström, Per LU ; Nyström, Håkan and Huyskens, Dominique Pierre (2002) In Radiology and Oncology 65(1). p.53-70
Abstract

BACKGROUND AND PURPOSE: An increasing number of radiotherapy centres is now aiming for clinical implementation of intensity modulated radiotherapy (IMRT), but--in contrast to conventional treatment--no national or international guidelines for commissioning of the treatment planning system (TPS) and acceptance tests of treatment equipment have yet been developed. This paper bundles the experience of five radiotherapy departments that have introduced IMRT into their clinical routine.

METHODS AND MATERIALS: The five radiotherapy departments are using similar configurations since they adopted the commercially available Varian solution for IMRT, regarding treatment planning as well as treatment delivery. All are using the sliding... (More)

BACKGROUND AND PURPOSE: An increasing number of radiotherapy centres is now aiming for clinical implementation of intensity modulated radiotherapy (IMRT), but--in contrast to conventional treatment--no national or international guidelines for commissioning of the treatment planning system (TPS) and acceptance tests of treatment equipment have yet been developed. This paper bundles the experience of five radiotherapy departments that have introduced IMRT into their clinical routine.

METHODS AND MATERIALS: The five radiotherapy departments are using similar configurations since they adopted the commercially available Varian solution for IMRT, regarding treatment planning as well as treatment delivery. All are using the sliding window technique. Different approaches towards the derivation of the multileaf collimator (MLC) parameters required for the configuration of the TPS are described. A description of the quality control procedures for the dynamic MLC, including their respective frequencies, is given. For the acceptance of the TPS for IMRT multiple quality control plans were developed on a variety of phantoms, testing the flexibility of the inverse planning modules to produce the desired dose pattern as well as assessing the accuracy of the dose calculation. Regarding patient treatment verification, all five centres perform dosimetric pre-treatment verification of the treatment fields, be it on a single field or on a total plan procedure. During the actual treatment, the primary focus is on patient positioning rather than dosimetry. Intracavitary in vivo measurements were performed in special cases.

RESULT AND CONCLUSION: The configurational MLC parameters obtained through different methods are not identical for all centres, but the observed variations have shown to be of no significant clinical relevance. The quality control (QC) procedures for the dMLC have not detected any discrepancies since their initiation, demonstrating the reliability of the MLC controller. The development of geometrically simple QC plans to test the inverse planning, the dynamic MLC modules and the final dose calculation has proven to be useful in pointing out the need to remodel the single pencil beam scatter kernels in some centres. The final correspondence between calculated and measured dose was found to be satisfactory by all centres, for QC test plans as well as for pre-treatment verification of clinical IMRT fields. An intercomparison of the man hours needed per patient plan verification reveals a substantial variation depending on the type of measurements performed.

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author
; ; ; ; ; ; ; and
publishing date
type
Contribution to journal
publication status
published
keywords
Humans, Phantoms, Imaging, Quality Control, Radiotherapy Dosage, Radiotherapy Planning, Computer-Assisted, Journal Article, Multicenter Study, Research Support, Non-U.S. Gov't
in
Radiology and Oncology
volume
65
issue
1
pages
18 pages
publisher
Onkoloski Institut Ljubljana
external identifiers
  • pmid:12413675
  • scopus:0036804332
ISSN
1318-2099
language
English
LU publication?
no
id
3e9b1f26-6e4f-4063-ba27-87fe3a006abf
date added to LUP
2018-03-01 15:10:25
date last changed
2024-05-27 07:45:59
@article{3e9b1f26-6e4f-4063-ba27-87fe3a006abf,
  abstract     = {{<p>BACKGROUND AND PURPOSE: An increasing number of radiotherapy centres is now aiming for clinical implementation of intensity modulated radiotherapy (IMRT), but--in contrast to conventional treatment--no national or international guidelines for commissioning of the treatment planning system (TPS) and acceptance tests of treatment equipment have yet been developed. This paper bundles the experience of five radiotherapy departments that have introduced IMRT into their clinical routine.</p><p>METHODS AND MATERIALS: The five radiotherapy departments are using similar configurations since they adopted the commercially available Varian solution for IMRT, regarding treatment planning as well as treatment delivery. All are using the sliding window technique. Different approaches towards the derivation of the multileaf collimator (MLC) parameters required for the configuration of the TPS are described. A description of the quality control procedures for the dynamic MLC, including their respective frequencies, is given. For the acceptance of the TPS for IMRT multiple quality control plans were developed on a variety of phantoms, testing the flexibility of the inverse planning modules to produce the desired dose pattern as well as assessing the accuracy of the dose calculation. Regarding patient treatment verification, all five centres perform dosimetric pre-treatment verification of the treatment fields, be it on a single field or on a total plan procedure. During the actual treatment, the primary focus is on patient positioning rather than dosimetry. Intracavitary in vivo measurements were performed in special cases.</p><p>RESULT AND CONCLUSION: The configurational MLC parameters obtained through different methods are not identical for all centres, but the observed variations have shown to be of no significant clinical relevance. The quality control (QC) procedures for the dMLC have not detected any discrepancies since their initiation, demonstrating the reliability of the MLC controller. The development of geometrically simple QC plans to test the inverse planning, the dynamic MLC modules and the final dose calculation has proven to be useful in pointing out the need to remodel the single pencil beam scatter kernels in some centres. The final correspondence between calculated and measured dose was found to be satisfactory by all centres, for QC test plans as well as for pre-treatment verification of clinical IMRT fields. An intercomparison of the man hours needed per patient plan verification reveals a substantial variation depending on the type of measurements performed.</p>}},
  author       = {{Van Esch, Ann and Bohsung, Jörg and Sorvari, Pekka and Tenhunen, Mikko and Paiusco, Marta and Iori, Mauro and Engström, Per and Nyström, Håkan and Huyskens, Dominique Pierre}},
  issn         = {{1318-2099}},
  keywords     = {{Humans; Phantoms, Imaging; Quality Control; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Journal Article; Multicenter Study; Research Support, Non-U.S. Gov't}},
  language     = {{eng}},
  number       = {{1}},
  pages        = {{53--70}},
  publisher    = {{Onkoloski Institut Ljubljana}},
  series       = {{Radiology and Oncology}},
  title        = {{Acceptance tests and quality control (QC) procedures for the clinical implementation of intensity modulated radiotherapy (IMRT) using inverse planning and the sliding window technique : experience from five radiotherapy departments}},
  volume       = {{65}},
  year         = {{2002}},
}