Measurement of radiation dose and imaging quality based on different image guidance methods for the URT-linac 506c(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2025年第12期
- Page:
- 1541-1547
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Measurement of radiation dose and imaging quality based on different image guidance methods for the URT-linac 506c
- Author(s):
- DENG Yongming1; CHENG Xiyuan2; HU Xingyuan1; TAN Peixin1; L?Fengquan1
- 1. Department of Radiation Oncology, Guangdong Provincial Peoples Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou 510080, China 2. Guangzhou Nanyi Yikang Medical Equipment Co., Ltd., Guangzhou 510515, China
- Keywords:
- Keywords: URT-linac 506c image-guided radiotherapy radiation dose CTDI phantom Catphan504
- PACS:
- R318.6；R811.1
- DOI:
- DOI:10.3969/j.issn.1005-202X.2025.12.001
- Abstract:
- Abstract: Objective To compare and analyze the radiation doses and imaging quality of the built-in electronic portal imaging device (EPID), megavoltage cone-beam computed tomography (MV-CBCT), and kilovoltage fan-beam computed tomography (kV-FBCT) in the domestic linear accelerator United Imaging URT-linac 506c for image-guided radiotherapy (IGRT), thereby providing data support for the clinical selection of appropriate IGRT modalities. Methods Cylindrical polymethyl methacrylate phantoms, PTW 300013 finger ionization chambers, Unfors Xi pencil ionization chambers, and Catphan504 phantoms were used to measure the radiation doses and imaging quality parameters of the EPID, MV-CBCT, and kV-FBCT systems of United Imaging URT-linac 506c under various scanning protocols. Specifically, EPID imaging was conducted using 0° and 90° orthogonal fields MV-CBCT was performed in the CBCT imaging mode and kV-FBCT was operated in the spiral CT imaging mode. The weighted radiation doses and imaging quality parameters of various IGRT modalities were calculated, and the differences in radiation doses and imaging quality parameters among different scanning protocols were analyzed and compared. Results In the IGRT mode of URT-linac 506c, the time consumption for image guidance using EPID, MV-CBCT Half Scan, MV-CBCT Full Scan/Half Fan, and kV-FBCT was (80.80±1.30), (75.00±2.92), (98.60±1.67), and (77.40±1.94) s, respectively, with statistically significant differences (Z=15.894, P=0.001). In terms of radiation dose, the imaging dose of EPID was lower than that of MV-CBCT and kV-FBCT and the minimum radiation doses of EPID, MV-CBCT and kV-FBCT were (2.30±0.67), (13.01±0.84), and (8.17±0.40) mGy, respectively. Regarding imaging quality, kV-FBCT outperformed both MV-CBCT and EPID. Specifically, kV-FBCT group could identify 6 line pairs, with a spatial resolution of 0.83 mm, while MV-CBCT group only resolve a maximum of 4 line pairs, with a spatial resolution of 1.25 mm. Although the EPID group was capable of distinguishing 11 line pairs, achieving a spatial resolution of 0.46 mm, it had inferior image noise level and density resolution. Conclusion The low-dose kV-FBCT scanning protocol is preferred for pediatric patients and patients with head and neck lesions. For thoracic and pelvic scans, low-dose mode kV-FBCT scanning protocol is also recommended.
Last Update: 2025-12-29