<abstract xmlns="http://www.w3.org/1999/xhtml">

<italic>Introduction:</italic> The geometrical precision of the machines is essential for effective and safe radiotherapy. Methods currently used for the measurement of the mechanical isocenter have many limitations. In this work, the optical system NaviRation for very precise measurement of mechanical accelerator isocenter is described. The results of the measurement of the isocenter for linear accelerator are also presented.
<italic>Materials and methods:</italic> An optical system for measuring the accelerator isocenter was designed and built. The optical system consists of two cameras recording the target position made according to a patented Zeiss technology. About 1,200 pairs of images are recorded during the rotation of the gantry, collimator and treatment table. Mathematical analysis of these images makes it possible to determine the location of the target center during rotation. In order to verify the accuracy of the measurements, a device simulating rotational motion was designed. The measurement results were also verified at the Central Office of Measures. The system must be calibrated each time before taking measurements. In this article, we present the results of measurements for the Versa HD accelerator.
<italic>Results:</italic> The accuracy of determining the current position of the axis of rotation was 0.15 mm. The time of taking measurements of all rotations does not exceed 20 minutes. Measurement results for the Versa HD accelerator showed that this accelerator met the criteria described by TG142 of the AAPM. The diameter of the gantry, collimator and table isocenter spheres were 1.5 mm, 0.3 mm and 0.4 mm, respectively.
<italic>Conclusions:</italic> The system enables precise, fast and simple mechanical isocenter measurement of the gantry, collimator and treatment table. It is also possible to perform all tests related to the measurements of distances, e.g. quality control of distance indicator, and distance of the table movement. The isocenter is measured independently of the accelerator for which measurements are made.
</abstract>

Introduction: The geometrical precision of the machines is essential for effective and safe radiotherapy. Methods currently used for the measurement of the mechanical isocenter have many limitations. In this work, the optical system NaviRation for very precise measurement of mechanical accelerator isocenter is described. The results of the measurement of the isocenter for linear accelerator are also presented.
Materials and methods: An optical system for measuring the accelerator isocenter was designed and built. The optical system consists of two cameras recording the target position made according to a patented Zeiss technology. About 1,200 pairs of images are recorded during the rotation of the gantry, collimator and treatment table. Mathematical analysis of these images makes it possible to determine the location of the target center during rotation. In order to verify the accuracy of the measurements, a device simulating rotational motion was designed. The measurement results were also verified at the Central Office of Measures. The system must be calibrated each time before taking measurements. In this article, we present the results of measurements for the Versa HD accelerator.
Results: The accuracy of determining the current position of the axis of rotation was 0.15 mm. The time of taking measurements of all rotations does not exceed 20 minutes. Measurement results for the Versa HD accelerator showed that this accelerator met the criteria described by TG142 of the AAPM. The diameter of the gantry, collimator and table isocenter spheres were 1.5 mm, 0.3 mm and 0.4 mm, respectively.
Conclusions: The system enables precise, fast and simple mechanical isocenter measurement of the gantry, collimator and treatment table. It is also possible to perform all tests related to the measurements of distances, e.g. quality control of distance indicator, and distance of the table movement. The isocenter is measured independently of the accelerator for which measurements are made.

Optical system for precise isocenter measurement

Polish Journal of Medical Physics and Engineering

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

{"article-title":"Optical system for precise isocenter measurement"}

Introduction: The geometrical precision of the machines is essential for effective and safe radiotherapy. Methods currently used for the measurement of the...

Optical system for precise isocenter measurement

Publié en ligne: 17 nov. 2023

Pages: 178 - 184

Reçu: 18 juil. 2013

Accepté: 17 oct. 2023

DOI: https://doi.org/10.2478/pjmpe-2023-0019

Mots clés
quality control, optical system, accelerator isocenter

© 2023 Paweł Kukołowicz et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Optical system for precise isocenter measurement

Publié en ligne: 17 nov. 2023

Pages: 178 - 184

Reçu: 18 juil. 2013

Accepté: 17 oct. 2023

DOI: https://doi.org/10.2478/pjmpe-2023-0019

Mots clésquality control, optical system, accelerator isocenter

© 2023 Paweł Kukołowicz et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Mots clés
quality control, optical system, accelerator isocenter