Optimizing gantry rotation of head and neck scanning for Elekta XVI cone beam CT(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2017年第11期
- Page:
- 1106-1109
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Optimizing gantry rotation of head and neck scanning for Elekta XVI cone beam CT
- Author(s):
- LI Zhengxian1; ZHAO Jingjing1; MA Yongle1; WANG Bosheng1; YANG Liting1; ZHOU Li2; ZHANG Yibao3
- 1. Department of Radiation Oncology, Jilin Guowen Hospital, Gongzhuling 136100, China; 2. Division of Radiation Physics, State Key Laboratory of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, China; 3. Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiotherapy, Peking University Cancer Hospital & Institute, Beijing 100142, China
- Keywords:
- ; Keywords: cone beam CT; protocol optimization; image-guided radiotherapy; imaging dose; radiological protection
- PACS:
- R730.55；R811.1
- DOI:
- DOI:10.3969/j.issn.1005-202X.2017.11.006
- Abstract:
- Abstract: Objective To compare the irradiation dose and image quality of Elekta XVI head and neck scans using standard full arc and fast partial arc protocols, and reduce the dose to sensitive organs by optimizing gantry rotation. Methods The standard head and neck CTDI phantom at 0, 3, 9 o’clock (upright setup), and 3, 0 o’clock (rotating the phantom by 45o, counter clockwise) were measured using a PTW electrometer and a CT chamber to simulate the irradiation dose to thyroid, left and right parotid, left and right lenses. Weighted CT dose index (CTDIw) of each protocol was also measured. In addition to the measurement of standard full and partial arc scan, the configuration script of partial arc scan was modified, where the gantry rotation was changed from 315o-160o to 335o-180o, and the dose in clockwise and counter clockwise scans were measured, respectively. Image quality was assessed using Catphan 503 phantom. Results CTDIw of standard full arc scanning was 0.81/0.81 mGy (0o/45o), which was about twice of that of partial arc scanning. The optimized partial arc clockwise scan and standard partial arc clockwise scan had the lowest dose and the highest, respectively, and compared with the latter, the former reduced dose to thyroid, left parotid, left lens, right lens, 0o and 45o CTDIw by 3.17%, 3.55%, 2.04%, 1.75%, 0.93% and 4.18%, respectively. Gantry rotation optimization did not affect image quality obviously, but improved clinical efficiency by reducing unnecessary gantry idle time. Conclusion Relative to standard full arc scan, partial arc XVI scan can achieve satisfactory image quality for head and neck at a lower dose. Optimized partial arc protocol can further reduce imaging dose to sensitive organs and improve clinical efficiency.
Last Update: 2017-11-23