<abstract xmlns="http://www.w3.org/1999/xhtml"><bold>Background.</bold> This study was designed to compare the quality assurance (QA) results of four dosimetric tools used for intensity modulated radiation therapy (IMRT) and to suggest universal criteria for the passing rate in QA, irrespective of the dosimetric tool used.<bold>Materials and methods.</bold> Thirty fields of IMRT plans from five patients were selected, followed by irradiation onto radiochromic film, a diode array (Mapcheck), an ion chamber array (MatriXX) and an electronic portal imaging device (EPID) for patient-specific QA. The measured doses from the four dosimetric tools were compared with the dose calculated by the treatment planning system. The passing rates of the four dosimetric tools were calculated using the gamma index method, using as criteria a dose difference of 3% and a distance-to-agreement of 3 mm.<bold>Results.</bold> The QA results based on Mapcheck, MatriXX and EPID showed good agreement, with average passing rates of 99.61%, 99.04% and 99.29%, respectively. However, the average passing rate based on film measurement was significantly lower, 95.88%. The average uncertainty (1 standard deviation) of passing rates for 6 intensity modulated fields was around 0.31 for film measurement, larger than those of the other three dosimetric tools.<bold>Conclusions.</bold> QA results and consistencies depend on the choice of dosimetric tool. Universal passing rates should depend on the normalization or inter-comparisons of dosimetric tools if more than one dosimetric tool is used for patient specific QA.</abstract>

Background. This study was designed to compare the quality assurance (QA) results of four dosimetric tools used for intensity modulated radiation therapy (IMRT) and to suggest universal criteria for the passing rate in QA, irrespective of the dosimetric tool used.Materials and methods. Thirty fields of IMRT plans from five patients were selected, followed by irradiation onto radiochromic film, a diode array (Mapcheck), an ion chamber array (MatriXX) and an electronic portal imaging device (EPID) for patient-specific QA. The measured doses from the four dosimetric tools were compared with the dose calculated by the treatment planning system. The passing rates of the four dosimetric tools were calculated using the gamma index method, using as criteria a dose difference of 3% and a distance-to-agreement of 3 mm.Results. The QA results based on Mapcheck, MatriXX and EPID showed good agreement, with average passing rates of 99.61%, 99.04% and 99.29%, respectively. However, the average passing rate based on film measurement was significantly lower, 95.88%. The average uncertainty (1 standard deviation) of passing rates for 6 intensity modulated fields was around 0.31 for film measurement, larger than those of the other three dosimetric tools.Conclusions. QA results and consistencies depend on the choice of dosimetric tool. Universal passing rates should depend on the normalization or inter-comparisons of dosimetric tools if more than one dosimetric tool is used for patient specific QA.

A comparison of the quality assurance of four dosimetric tools for intensity modulated radiation therapy

Department of Bio-Convergence Engineering, Korea University, Seoul, Korea

Proton Therapy Center, National Cancer Center, Goyang, Korea

McLaren Proton Therapy Center, Karmanos Cancer Institute, Flint, MI, USA

Department of Radiation Oncology, Ilsan Hospital, Goyang, Korea

Department of Radiation Oncology, Sun Hospital, Daejeon, Korea

Radiology and Oncology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Background. This study was designed to compare the quality assurance (QA) results of four dosimetric tools used for intensity modulated radiation therapy...

A comparison of the quality assurance of four dosimetric tools for intensity modulated radiation therapy

Published Online: Aug 21, 2015

Page range: 307 - 313

Received: Nov 10, 2014

Accepted: Jan 18, 2015

DOI: https://doi.org/10.1515/raon-2015-0021

Keywords
intensity modulated radiation therapy, quality assurance, dosimetric tool, gamma index

© 2015 Jaeman Son et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

A comparison of the quality assurance of four dosimetric tools for intensity modulated radiation therapy

Published Online: Aug 21, 2015

Page range: 307 - 313

Received: Nov 10, 2014

Accepted: Jan 18, 2015

DOI: https://doi.org/10.1515/raon-2015-0021

Keywordsintensity modulated radiation therapy, quality assurance, dosimetric tool, gamma index

© 2015 Jaeman Son et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
intensity modulated radiation therapy, quality assurance, dosimetric tool, gamma index