Effect of respiration-induced motion on a three-dimensional magnetic resonance imaging-based adaptive radiotherapy workflow in a 1.5T magnetic resonance linear accelerator
Year: 2025
Type: article
Abstract: Background: The long acquisition time of three-dimensional (3D) magnetic resonance imaging (MRI) makes it vulnerable to motion-induced artifacts such as blurring and ghosting, which may compromise target delineation and dose accuracy. Although motion management strategies such as four-dimensional MRI and cine MRI have been proposed, the specific influence of respiratory parameters-particularly amplitude and frequency-on the geometric and dosimetric precision of magnetic resonance-guided adaptive radiotherapy (RT) remains inadequately quantified. This study thus aimed to systematically evaluate how respiratory-induced linear translational motion affects delineation accuracy and dose distribution in MRI-based adaptive RT. Methods: ) generated with the digital phantom. Key delineation metrics [e.g., Dice similarity coefficient (DSC), Hausdorff distance (HD), and mean surface distance (MSD)] and dosimetric parameters (e.g., dose received by 95% of the volume) were evaluated, and statistical analyses were performed to assess the correlations between respiratory motion characteristics and the observed variations. Results: dose coverage at higher amplitudes, with the dose received by 95% of the volume decreasing by 481.55 cGy at 12.50 mm relative to the prescribed total dose of 4,500 cGy. In contrast, respiratory frequency had minimal impact, with changes remaining within clinically acceptable ranges. Conclusions: This study investigated the impact of respiratory-induced linear translational motion on ITV delineation and dosimetric accuracy in MR-guided RT. It was found that large respiratory amplitudes significantly compromised geometric and dosimetric precision, whereas frequency had minimal influence. The results emphasize the limitations of 3D Cartesian MRI due to motion-averaged artifacts and support the development of advanced imaging techniques for improving ITV delineation accuracy.
Authors: Yongchang Wu, Hang Yu, Qing Xiao, Jing Li, Weige Wei, Lian Duan, Sen Bai, Guangjun Li
Language: English
Subfield: Radiation
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4411901764