Auditing local methods for quality assurance in radiotherapy using the same set of predefined treatment plans

Enrica Seravalli, Antonetta C. Houweling, Leo Van Battum, Thom A. Raaben, Marc Kuik, Jacco A. de Pooter, Marion P.R. Van Gellekom, Jochem Kaas, Wilfred de Vries, Erik A. Loeff, Jeroen B. Van de Kamer*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Background and purpose: Local implementation of plan-specific quality assurance (QA) methods for intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) treatment plans may vary because of dissimilarities in procedures, equipment and software. The purpose of this work is detecting possible differences between local QA findings and those of an audit, using the same set of treatment plans. Methods: A pre-defined set of clinical plans was devised and imported in the participating institute's treatment planning system for dose computation. The dose distribution was measured using an ionisation chamber, radiochromic film and an ionisation chamber array. The centres performed their own QA, which was compared to the audit findings. The agreement/disagreement between the audit and the institute QA results were assessed along with the differences between the dose distributions measured by the audit team and computed by the institute. Results: For the majority of the cases the results of the audit were in agreement with the institute QA findings: ionisation chamber: 92%, array: 88%, film: 76% of the total measurements. In only a few of these cases the evaluated measurements failed for both: ionisation chamber: 2%, array: 4%, film: 0% of the total measurements. Conclusion: Using predefined treatment plans, we found that in approximately 80% of the evaluated measurements the results of local QA of IMRT and VMAT plans were in line with the findings of the audit. However, the percentage of agreement/disagreement depended on the characteristics of the measurement equipment used and on the analysis metric.

Original languageEnglish
Pages (from-to)19-25
Number of pages7
JournalPhysics and Imaging in Radiation Oncology
Volume5
DOIs
Publication statusPublished - Jan 2018

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