Sensitivity of ArcCheck to detect dose delivery errors in helical tomotherapy(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2021年第6期
- Page:
- 666-671
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Sensitivity of ArcCheck to detect dose delivery errors in helical tomotherapy
- Author(s):
- YAN Bing1; WU Ailin2; XUE Xudong1; ZHANG Hongyan1; WU Aidong1
- 1. Department of Radiation Oncology, the First Affiliated Hospital of University of Science and Technology of China/Anhui Provincial Hospital, Hefei 230001, China 2. Department of Radiation Oncology, the First Affiliated Hospital of University of Science and Technology of China (West District)/Anhui Provincial Cancer Hospital, Hefei 230001, China
- Keywords:
- Keywords: nasopharyngeal carcinoma helical tomotherapy ArcCheck quality assurance Gamma analysis
- PACS:
- R318；R815.2
- DOI:
- DOI:10.3969/j.issn.1005-202X.2021.06.002
- Abstract:
- Abstract: Objective To measure the passing rates of helical tomotherapy (HT) plan with ArcCheck, and to explore the sensitivity of ArcCheck to detect the errors which are introduced in couch movement, gantry rotation period, gantry starting angle and leaf open time. Methods The plans of 9 patients with nasopharyngeal carcinoma who underwent HT were analyzed. For each patient, error plan corresponding to the original plan was generated using a self-compiled program. Point dose and Gamma analysis were used for calculating clinically detectable errors. Results The average Gamma passing rates of the 9 original HT plans were 97.49%±1.08% and 73.38%±4.31% under the criteria of 3%/2 mm and 2%/1 mm, respectively. When adopting the criterion of 3%/2mm, the detectable errors were -1.58% and 1.38% (upper and lower thresholds) for couch movement, -1.68% and 1.31% (upper and lower thresholds) for gantry rotation period, 2.50° for gantry starting angle, 1.62% for leaf open time. When adopting the criterion of 2%/1mm, the detection accuracy was improved, and the corresponding minimum detectable errors were -0.69% and 1.27% for couch movement, -0.69% and 0.69% for gantry rotation period, 2.06°for gantry starting angle, and 0.52% for leaf open time, respectively. Conclusion Compared with ArcCheck only, the combination of ion chamber measurements with ArcCheck do not improve error detection accuracy. ArcCheck can be used to detect clinically relevant dose delivery errors. Selecting more strict criteria for Gamma passing rate calculation can significantly improve the detection accuracy of error plan.
Last Update: 2021-06-29