Simulation Study on the Effect of Constant Hole Length of Curved Diverging Collimators for Radiation Monitoring Systems

Cha, Hyemi; Leem, Seowung; Cho, Kyeyoung; Kang, Cheolung; Bae, Sun Hyun; Yu, Byeongjae; Yeom, Jung-Yeol; Lee, Hakjae; Lee, Kisung

doi:10.1109/tns.2021.3074532

Cited by 5 publications

(2 citation statements)

References 12 publications

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“…The spatial resolution and image quality of a diverging collimator tend to deteriorate as the position of the radiation source being detected deviates from the center of the field of view (FOV) ( Cha et al, 2021 ). Consequently, we conducted additional assessments of the optimized diverging collimator to ascertain its performance across varying source positions ( Cha et al, 2021 ). Table 1 presents the geometric parameters of the optimized diverging collimator.…”

Section: Methodsmentioning

confidence: 99%

Monte Carlo simulation study of an in vivo four-dimensional tracking system with a diverging collimator for monitoring radiation source (Ir-192) location during brachytherapy: proof of concept and feasibility

Oh,

Lee,

Kim

et al. 2024

Front. Physiol.

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Introduction: The aim of this study was to demonstrate the potential of an in vivo four-dimensional (4D) tracking system to accurately localize the radiation source, Iridium-192 (Ir-192) in high-dose rate brachytherapy.Methods: To achieve time-dependent 3D positioning of the Ir-192 source, we devised a 4D tracking system employing multiple compact detectors. During the system’s design phase, we conducted comprehensive optimization and analytical evaluations of the diverging collimator employed for detection purposes. Subsequently, we executed 3D reconstruction and positioning procedures based on the 2D images obtained by six detectors, each equipped with an optimized diverging collimator. All simulations for designing and evaluating the 4D tracking system were performed using the open-source GATE (v9.1) Monte Carlo platform based on the GEANT4 (v10.7) toolkit. In addition, to evaluate the accuracy of the proposed 4D tracking system, we conducted simulations and 3D positioning using a solid phantom and patient data. Finally, the error between the reconstructed position coordinates determined by the tracking system and the original coordinates of the Ir-192 radiation source was analyzed.Results: The parameters for the optimized diverging collimator were a septal thickness of 0.3 mm and a collimator height of 30 mm. A tracking system comprising 6 compact detectors was designed and implemented utilizing this collimator. Analysis of the accuracy of the proposed Ir-192 source tracking system found that the average of the absolute values of the error between the 3D reconstructed and original positions for the simulation with the solid phantom were 0.440 mm for the x coordinate, 0.423 mm for the y coordinate, and 0.764 mm for the z coordinate, and the average Euclidean distance was 1.146 mm. Finally, in a simulation based on data from a patient who underwent brachytherapy, the average Euclidean distance between the original and reconstructed source position was 0.586 mm.Discussion: These results indicated that the newly designed in vivo 4D tracking system for monitoring the Ir-192 source during brachytherapy could determine the 3D position of the radiation source in real time during treatment. We conclude that the proposed positioning system has the potential to make brachytherapy more accurate and reliable.

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Section: Methodsmentioning

confidence: 99%

Monte Carlo simulation study of an in vivo four-dimensional tracking system with a diverging collimator for monitoring radiation source (Ir-192) location during brachytherapy: proof of concept and feasibility

Oh,

Lee,

Kim

et al. 2024

Front. Physiol.

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“…Based on the results of previous studies, we configured the parameters of the diverging collimator for the high-energy gamma imaging of Ir-192, which is used for brachytherapy in clinical practice, as follows [22]: as shown in figure 1(a), first, the distance (𝑠) between the source and detector surface was set to 50 cm; the height (ℎ) of the collimator, 30 mm; the focal length ( 𝑓 ), 60 mm; the hole size (𝑑), 0.5 mm; the septal thickness (𝑡), 0.3 mm; and the diverging angle, 45 • , considering the resolution and sensitivity performance of the collimator (table 1). Regarding the parameters of the pinhole collimator, the acceptance angle was set to 45 • and the hole diameter to 0.5 mm, and the distance between the source and detector surface was set to 50 cm to compare the performance with that of the diverging collimator (table 2).…”

Section: Performance Evaluation Of Collimatorsmentioning

confidence: 99%

Feasibility study of real-time imaging of an Ir-192 source using compact gamma camera with curved diverging collimator for brachytherapy

Oh,

Jeong,

Choi

et al. 2024

J. Inst.

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Brachytherapy is a treatment method that requires the accurate positioning of a radioactive source to deliver high doses to a tumor while minimizing exposure to surrounding tissues. Herein, we propose a compact gamma camera system based on a diverging collimator for real-time source positioning during brachytherapy. In the process of developing and fabricating such a gamma camera system, Monte Carlo simulations for diverging and pinhole collimators are performed under conditions that are similar to the actual detection environment, with the camera-to-source distance set at 50 cm to verify the feasibility of the gamma camera. Full width at half maximum (FWHM) and signal-to-noise ratio (SNR) values are analyzed based on the horizontal and vertical profiles at each location as the source shifts stepwise from the center to the right and diagonal direction. On average, the diverging collimator had FWHM values of 18 and 13 mm and SNR values of 30 and 31, while the pinhole collimator had FWHM values of 26 and 25 mm and SNR values of 47 and 46 when profiled horizontally and vertically. The diverging collimator has a lower SNR than pinhole collimator but performs better in terms of spatial resolution. Additionally, to test the performance of the manufactured gamma camera, the distance between the camera and the source was set to 100 cm and an experiment was conducted. The experimental results exhibit a trend similar to the simulation. Numerically, the average FWHM value were 39 mm in the vertical direction and 71 mm in the horizontal direction. Additionally, the average SNR values were 27 for the vertical direction and 17 for the horizontal direction. Based on these results, we confirm the possibility of Ir-192 source imaging.

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Optimization of the design parameters for a thyroid care nuclide monitoring diverging collimator using Monte Carlo simulation

Han

Lee

Kim

et al. 2022

J. Korean Phys. Soc.

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Simulation Study on the Effect of Constant Hole Length of Curved Diverging Collimators for Radiation Monitoring Systems

Cited by 5 publications

References 12 publications

Monte Carlo simulation study of an in vivo four-dimensional tracking system with a diverging collimator for monitoring radiation source (Ir-192) location during brachytherapy: proof of concept and feasibility

Monte Carlo simulation study of an in vivo four-dimensional tracking system with a diverging collimator for monitoring radiation source (Ir-192) location during brachytherapy: proof of concept and feasibility

Feasibility study of real-time imaging of an Ir-192 source using compact gamma camera with curved diverging collimator for brachytherapy

Optimization of the design parameters for a thyroid care nuclide monitoring diverging collimator using Monte Carlo simulation

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