Comparison of optical positioning system and cone-beam computed tomography on positioning accuracy in radiotherapy for nasopharyngeal carcinoma(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2021年第2期
- Page:
- 162-167
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Comparison of optical positioning system and cone-beam computed tomography on positioning accuracy in radiotherapy for nasopharyngeal carcinoma
- Author(s):
- ZHANG Yuqi1; GE Yun1; CAI Jing2; CHU Kaiyue2; JIN Jianhua2; GE Binbin2; CHEN Ying1; HUANG Xiaolin1; LI Weifeng1
- 1. School of Electronic Science and Engineering, Nanjing University, Nanjing 210023, China 2. Department of Radiation Oncology, Nantong Tumor Hospital, Nantong 226300, China
- Keywords:
- Keywords: nasopharyngeal carcinoma optical positioning system cone-beam computed tomography positioning accuracy radiotherapy positioning
- PACS:
- R811.1；R730.55
- DOI:
- DOI:10.3969/j.issn.1005-202X.2021.02.007
- Abstract:
- Abstract: Objective To quantitatively study the differences in positioning accuracy between optical positioning system (OPS) and cone-beam computed tomography (CBCT) in the radiotherapy for nasopharyngeal carcinoma. Methods Twenty-one patients with nasopharyngeal carcinoma who were admitted to Nantong Cancer Hospital were enrolled in the study. All the patients were immobilized with thermoplastic head-and-shoulder mask. Before CT scan, 6 OPS infrared positioning balls were affixed to the mask. kV-CBCT scan was performed to validate the positioning errors before the first treatment, and the couch was then shifted according to the CBCT validation results. The couch shift when using CBCT and the deviations detected by OPS after couch shift were recorded. The positioning results of the room laser system and those of OPS were recorded, and then compared with those of CBCT which were taken as the reference. When the positioning errors were no more than 2.0 mm, OPS was considered consistent with CBCT in positioning. Results Compared with the room laser system, OPS remarkably improved the positioning accuracy of nasopharyngeal carcinoma radiotherapy. The consistencies between OPS and CBCT were 95.2%, 71.4% and 100.0% in left-right, anterior-posterior and superior-inferior directions, respectively. The error caused by the bending of the cervical vertebrae when the cervical vertebrae was taken as the reference point in treatment planning system couldnt be avoided in positioning using CBCT, which led to a large deviation between CBCT and OPS in anterior-posterior direction. Conclusion OPS which achieves real-time, accurate and rapid patient positioning can replace the room laser system to greatly improve the positioning accuracy in nasopharyngeal carcinoma radiotherapy. OPS also has a high consistency with CBCT in positioning in nasopharyngeal carcinoma radiotherapy. Moreover, OPS can be used in all fractions.
Last Update: 2021-02-02