Reference quality assurance method for beam time delay of RPM respiratory gating system for radiotherapy(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2023年第3期
- Page:
- 261-266
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Reference quality assurance method for beam time delay of RPM respiratory gating system for radiotherapy
- Author(s):
- YAO Kaining1; WANG Meijiao1; LIU Jiacheng1; WANG Qingying2; WANG Ruoxi1; YUE Haizhen1; ZHOU Shun1; WU Hao1; DU Yi1
- 1. Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing)/Department of Radiotherapy, Peking University Cancer Hospital & Institute, Beijing 100142, China 2. Institute of Medical Technology, Peking University Health Science Center, Beijing 100191, China
- Keywords:
- Keywords: RPM respiratory gating system time delay quality assurance radiotherapy
- PACS:
- R318；R811.1
- DOI:
- DOI:10.3969/j.issn.1005-202X.2023.03.001
- Abstract:
- Abstract: Objective To propose a reference quality assurance (QA) method for beam time delay of RPM respiratory-gated radiotherapy, and provide the measurement results of time delay on VB and EDGE accelerators under reference conditions. Methods A trapezoidal QA breathing curve was designed and loaded into motion phantom, and a W-L phantom driven by motion phantom was scanned with CT. Two types of QA plans which were designed for beam on and off time delay measurements were executed on accelerator, and EPID was used to acquire static reference images and motion images of phantom. The time delay was reversed by analyzing the position deviations of metal ball in motion and reference images. The proposed method was verified on VB and EDGE accelerators. Results The beam on time delay on VB and EDGE accelerators was less than 100 ms, and the beam off time delay on VB was close to that of EDGE (14 ms vs 22 ms). The beam on time delay of 10FFF was almost the same at each dose rate, while the beam on time delay of 6FFF, 6 MV and 10 MV was increased slightly with dose rate. The beam off time delay at each dose rate and 4 energies were small and relatively consistent. Except 10FFF, the time delay has s a tendency to decrease over the increase of the dose rate. Conclusion The proposed method and conditions for RPM time delay measurement have high measurement reliability and clinical practicality, and the RPM respiratory gating system exhibited fast response. This study provides significant methodology and reference data for quality assurance of respiratory gating system.
Last Update: 2023-03-29