The suitability of the EPIbeam system for dosimetric verification of radiotherapy treatment plans
Abstract
Introduction
The aim of this study was to validate the DOSIsoft’s EPIbeam portal dosimetry system for controlling dose distribution in radiotherapy delivered by dynamic techniques.
Material and methods
Treatment plans were verified using multidetector matrices and an EPID dosimetry panel. Additionally, functional tests and simulations of potential errors that may occur during irradiation were performed using the EPID panel. The comparison of dose distributions planned in the treatment planning system with the distributions obtained as a result of the application of two verification methods was performed in dedicated software using the gamma coefficient analysis method. A statistical analysis of the obtained results was performed to determine the most advantageous EPIbeam system settings and the analysis criteria to be applied. The EPIbeam system was then compared with previously used system.
Results
Statistical analysis indicated that one of the three accelerator model libraries created in the EPIbeam system (library 15, DLS = 0.4 mm) should be excluded from clinical use. Significant differences were observed for this library when applying the 2%, 2 mm gamma criterion. When applying the 2%, 2 mm criterion with the accelerator model set in library 8 (DLS = 0.0 mm), the results show no differences compared to multidetector matrices. This indicated that verification performed for these settings in the EPIbeam system yielded results similar to verification performed using matrices.
Conclusions
Despite certain limitations, EPIbeam proved to be a reliable tool for dosimetric verification of treatment plans implemented using the dynamic VMAT technique.
© 2026 Aleksandra Żaba, Andrzej Chmiel, Katarzyna Matusiak, published by Polish Society of Medical Physics
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