Evaluation of DVH-based treatment plan verification in addition to gamma passing rates for head and neck IMRT

Ruurd Visser*, David J. L. Wauben, Martijn de Groot, Roel J. H. M. Steenbakkers, Henk P. Bijl, Jeremy Godart, Aart van t Veld, Johannes A. Langendijk, Erik W. Korevaar

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

21 Citations (Scopus)


Background and purpose: Treatment plan verification of intensity modulated radiotherapy (IMRT) is generally performed with the gamma index (GI) evaluation method, which is difficult to extrapolate to clinical implications. Incorporating Dose Volume Histogram (DVH) information can compensate for this. The aim of this study was to evaluate DVH-based treatment plan verification in addition to the GI evaluation method for head and neck IMRT.

Materials and methods: Dose verifications of 700 subsequent head and neck cancer IMRT treatment plans were categorised according to gamma and DVH-based action levels. Fractionation dependent absolute dose limits were chosen. The results of the gamma- and DVH-based evaluations were compared to the decision of the medical physicist and/or radiation oncologist for plan acceptance.

Results: Nearly all treatment plans (99.7%) were accepted for treatment according to the GI evaluation combined with DVH-based verification. Two treatment plans were re-planned according to DVH-based verification, which would have been accepted using the evaluation alone. DVH-based verification increased insight into dose delivery to patient specific structures increasing confidence that the treatment plans were clinically acceptable. Moreover, DVH-based action levels clearly distinguished the role of the medical physicist and radiation oncologist within the Quality Assurance (QA) procedure.

Conclusions: DVH-based treatment plan verification complements the GI evaluation method improving head and neck IMRT-QA. (C) 2014 Elsevier Ireland Ltd. All rights reserved.

Original languageEnglish
Pages (from-to)389-395
Number of pages7
JournalRadiotherapy and Oncology
Issue number3
Publication statusPublished - Sept-2014


  • Quality Assurance
  • Dose Volume Histogram
  • Action levels
  • Plan verification
  • IMRT
  • 3D
  • QA

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