Radiation Physics and Engineering
A peer-reviewed journal published by K. N. Toosi University of Technology

Design and construction of a quality control phantom for evaluation of the clinical imaging performance of electronic portal imaging devices

Document Type : Research Article

Authors

Nahid Hajiloo 1
Mostafa Mohammadi 2
Farzaneh Ghasemifard 3
Mahmoud-Reza Aghamiri 3

1 Radiation Application Research School, Nuclear Science and Technology Research Institute, P.O. Box 31485-498, Karaj, Iran

2 Secondary Standard Dosimetry Laboratory (SSDL), Pars Isotope Co., Karaj, Iran

3 Medical Radiation Engineering, Shahid Beheshti University, Tehran, Iran

https://doi.org/10.22034/rpe.2025.528889.1279
Abstract
This study presents the design and construction of a quality control phantom for evaluating the clinical imaging performance of electronic portal imaging devices (EPIDs) used in radiation therapy. The phantom, incorporating lead sheets of varying thicknesses and a plexiglass scaling component, enables the assessment of key image quality parameters, including Noise, Uniformity, Contrast-to-Noise Ratio (CNR), Signal-to-Noise Ratio (SNR), Contrast, and pixel-to-millimeter scaling. A dedicated software application, developed using LabVIEW, facilitates automated and standardized analysis of EPID images. The phantom was tested across two radiotherapy centers, revealing differences in EPID performance, with Center A demonstrating lower Noise (0.5 vs. 1.6), better Uniformity (1.9 vs. 9.3), and higher CNR (69.3 vs. 45.6) and SNR values compared to Center B. The phantom's design, inspired by established models like the Las Vegas and PTW phantoms, supports both qualitative and quantitative evaluations, meeting TG142 standards for spatial resolution (>2 mm). This work highlights the efficacy of tailored quality assurance tools in enhancing EPID performance, ensuring precise radiation therapy delivery and improved patient outcomes.

Highlights

  • A phantom was designed and constructed for the purpose of quality control of the EPID performance.
  • A software was developed to analyze the acquired images, and parameters of image quality.
  • Image quality parameters were evaluated using constructed phantom.

Keywords

Keywords: EPID QC phantom
Image quality parameters
Radiotherapy
Verification

 

Copyright
RPE is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0).

Conflict of Interest

‎The authors declare no potential conflict of interest regarding the publication of this work‎.

Funding

‎The authors declare that no funds‎, ‎grants‎, ‎or other financial support were received during the preparation of this manuscript‎.

 

 
Association, N. E. M. et al. (2004). National Electrical Manufacturers Association. Digital Imaging and Communications in Medicine (DICOM).
Boudet, J., Aubignac, L., Beneux, A., et al. (2022). Evaluation of QA software system analysis for the static picket fence test. Journal of Applied Clinical Medical Physics, 23(7):e13618.
Cho, J.-H., Lee, J.-H., Jung, J.-Y., et al. (2015). Evaluation of image quality for various electronic portal imaging devices in radiation therapy. Journal of Radiological Science and Technology, 38(4):451–461.
Cremers, F., Frenzel, T., Kausch, C., et al. (2004). Performance of electronic portal imaging devices (EPIDs) used in radiotherapy: image quality and dose measurements. Medical Physics, 31(5):985–996.
Diklic, A., Dundara Debeljuh, D., Jurkovic, S., et al. (2013). Quality Control of Mega Voltage Portal Imaging System.
Dogan, N., Mijnheer, B. J., Padgett, K., et al. (2023). AAPM Task Group Report 307: use of EPIDs for patient-specific IMRT and VMAT QA. Medical Physics, 50(8):e865–e903.
El-Bassiouni, M., Davis, J. B., El-Attar, I., et al. (2006). Target motion variability and on-line positioning accuracy during external-beam radiation therapy of prostate cancer with an endorectal balloon device. Strahlentherapie und Onkologie, 182(9):531–536.
Gagel, B., Schramm, O., Harms, W., et al. (2002). The Electronic Portal Imaging System Siemens Beamview Plus  Versus the Conventional Verification Films CEA-TVS R? and DuPont CQL-7 A Critical Appraisal of Visual Image Quality: A Critical Appraisal of Visual Image Quality. Strahlentherapie und Onkologie, 178(8):446–452.
Herman, M. G., Balter, J. M., Jaffray, D. A., et al. (2001). Clinical use of electronic portal imaging: report of AAPM Radiation Therapy Committee Task Group 58. Medical Physics, 28(5):712–737.
Huang, M., Huang, D., Zhang, J., et al. (2017). Preliminary study of clinical application on IMRT three-dimensional dose verification-based EPID system. Journal of Applied Clinical Medical Physics, 18(4):97–105.
Klein, E. E., Hanley, J., Bayouth, J., et al. (2009a). Quality assurance of medical accelerators: report of AAPM Radiation Therapy Committee Task Group 142. Medical Physics, 36:4197–4212.
Klein, E. E., Hanley, J., Bayouth, J., et al. (2009b). Task Group 142 report: Quality assurance of medical accelerators. Medical Physics, 36(9Part1):4197–4212.
Kruse, J. J., Herman, M. G., Hagness, C. R., et al. (2002). Electronic and film portal images: a comparison of landmark visibility and review accuracy. International Journal of Radiation Oncology* Biology* Physics, 54(2):584–591.
Kry, S. F., Bednarz, B., Howell, R. M., et al. (2017). AAPM TG 158: measurement and calculation of doses outside the treated volume from external-beam radiation therapy. Medical Physics, 44(10):e391–e429.
Lee, S., Yan, G., Bassett, P., et al. (2016). Use of local noise power spectrum and wavelet analysis in quantitative image quality assurance for EPIDs. Medical Physics, 43(9):4996–5008.
Li, Y., Chen, L., Zhu, J., et al. (2017). A quantitative method to the analysis of MLC leaf position and speed based on EPID and EBT 3 film for dynamic IMRT treatment with different types of MLC. Journal of Applied Clinical Medical Physics, 18(4):106–115.
McGarry, C., Grattan, M., and Cosgrove, V. (2007). Optimization of image quality and dose for Varian aS500 electronic portal imaging devices (EPIDs). Physics in Medicine & Biology, 52(23):6865.
Noble, D., Ramaesh, R., Brothwell, M., et al. (2024). The evolving role of novel imaging techniques for radiotherapy planning. Clinical Oncology, 36(8):514–526.
Peca, S., Sinha, R. S., Brown, D. W., et al. (2017). In vivo portal imaging dosimetry identifies delivery errors in rectal cancer radiotherapy on the belly board device. Technology in Cancer Research & Treatment, 16(6):956–963.
Tzomakas, M. K., Peppa, V., Alexiou, A., et al. (2023). A phantom based evaluation of the clinical imaging performance of electronic portal imaging devices. Heliyon, 9(10).
Radiation Physics and Engineering
Volume 6, Issue 4
Autumn 2025
Pages 39-45

  • Receive Date 07 June 2025
  • Revise Date 25 August 2025
  • Accept Date 29 August 2025

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