ObjectiveBy statistical analysis of the weekly test results of 4 medical electron linear accelerators in the past 3 years, to find and summarize the regularity and characteristics of periodic quality control of accelerators, so as to provide recommendations for the rational maintenance of accelerators and radiotherapy for cancer patients. Methods According to the quality control content recommended by domestic and foreign reports and literatures, five items such as output dose stability, laser lamp position, image center and mechanical center coincidence test, optical distance scale accuracy and optical field size were selected to carry out periodic inspection work. Results The four accelerators were American Varian Trilogy (old), Swedish Elekta Precise, American Varian Unique and American Varian Trilogy (new) in order of service time. The passing rates of the output dose test were 97.5%, 93.2%, 96.3% and 100%, respectively. The average maximum deviation of laser lamp position was 0.84, 0.76, 0.82 and 0.64 mm, respectively. The average maximum deviation of the coincidence degree between image center and mechanical center was 1.19, 1.05, 0.83 and 0.81 mm, respectively. The average maximum deviation was 1.05, 0.72, 1.72 and 0.91 mm, respectively. The average maximum deviation of optical field size was 0.91, 0.82, 0.79 and 0.60 mm, respectively. Varian Trilogy (new), the shortest-serving and highest-configuration accelerator, ranked in the top two for each of the four accelerators in the horizontal rankings, while all the others ranked in the bottom for at least one test. Conclusion The shorter the service time of the medical electron linear accelerator weekly inspection project, the higher the comprehensive standard rate, more suitable for the implementation of more complex treatment plans, to undertake more radiotherapy tasks. In addition, the higher the accelerator configuration produced by the same company, the higher the output dose stability and the accuracy of the optical gauge. The position of laser light in the horizontal direction of each accelerator is more prone to deviation. The more C-arm accelerators participate in image guidance, the greater the probability of image center deviation. The greater the difference from 100 cm, the greater the probability of deviation.
Key words
medical electron linear accelerator; radiation therapy; quality assurance; weekly check; test accuracy; service time
{{custom_keyword}} /
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
References
[1] 杨绍洲, 陈龙华, 张树军. 医用电子直线加速器[M]. 北京: 人 民军医出版社, 2004: 213-226.
[2] Krauss RF, Balik S, Cirino ET, et al. AAPM Medical Physics Practice Guideline 8.b: linear accelerator performance tests[J]. J Appl Clin Med Phys, 2023, 24(11): e14160.
[3] Medical electron accelerators in the range 1 MeV-50 MeVguidelines for functional performance characteristics[S]. International Electro-technical Commission Publication, 1989.
[4] American College of Medical Physics. Radiation control and quality assurance in radiation oncology: a suggested protocol[R]. American College of Medical Physics Report Series No.2, 1986.
[5] Kutcher GJ, Coia L, Gillin M, et al. Comprehensive QA for radiation oncology: report of AAPM Radiation Therapy Committee Task Group 40[J]. Med Phys, 1994, 21(4): 581-618.
[6] Klein EE, Hanley J, Bayouth J, et al. Task Group 142 report: quality assurance of medical accelerators[J]. Med Phys, 2009, 36(9): 4197-4212.
[7] 国家质量监督检验检疫总局. 医用电子加速器辐射源: JJG 589-2008[S]. 2008.
[8] 中华人民共和国国家质量监督检验检疫总局, 中国国家标准 化管理委员会. 医用电子加速器性能和试验方法: GB 15213- 2016[S]. 2016.
[9] 国家癌症中心, 国家肿瘤质控中心. 医用电子直线加速器质 量控制指南: NCC/T-RT 001-2019[S]. 2019.
[10] 顾香莲, 顾煜恺, 龚卿. 基于NCC/T-RT 001-2019质控指南进行 医用加速器质控的研究[J]. 中国医疗设备, 2021, 36(7): 68-72.
Gu XL, Gu YK, Gong Q. Research on quality control of medical accelerator based on the NCC/T-RT 001-2019 guidelines[J]. China Med Devices, 2021, 36(7): 68-72.
[11] Hossain M. Output trends, characteristics, and measurements of three megavoltage radiotherapy linear accelerators[J]. J Appl Clin Med Phys, 2014, 15(4): 4783.
[12] 刘卓伦, 张艺宝, 岳海振, 等. 医用直线加速器中心轴绝对剂 量输出长期稳定性对比分析[J]. 中国医学物理学杂志, 2016, 33(1): 1-5.
Liu ZL, Zhang YB, Yue HZ, et al. Comparative analysis on long-term stability of absolute dose output at central axis of medical[J]. Chin J Med Phys, 2016, 33(1): 1-5.
[13] Matsushita N, Nakamura M, Sasaki M, et al. Analyses of integrated EPID images for on-treatment quality assurance to account for interfractional variations in volumetric modulated arc therapy[J]. J Appl Clin Med Phys, 2020, 21(1): 110-116.
[14] Biltekin F, Yedekci Y, Ozyigit G. Feasibility of novel in vivo EPID dosimetry system for linear accelerator quality control tests[J]. Australas Phys Eng Sci Med, 2019, 42: 995-1009.
[15] Razinskas G, Schindhelm R, Sauer OA, et al. Sensitivity and specificity of Varian Halcyon’s portal dosimetry for plan-specific pre-treatment QA[J]. J Appl Clin Med Phys, 2023: e14001.
[16] O’Daniel JC, Yin FF. Quantitative approach to failure mode and effect analysis for linear accelerator quality assurance[J]. Int J Radiat Oncol Biol Phys, 2017, 98(1): 56-62.
[17] Pearson M, Butterworth V, Misson-Yates S, et al. Application of failure mode and effects analysis to validate a novel hybrid Linac QC program that integrates automated and conventional QC testing[J]. J Appl Clin Med Phys, 2022, 23(12): e13798.
[18] Liu L, Shen L, Yang Y, et al. Modeling linear accelerator (Linac) beam data by implicit neural representation learning for commissioning and quality assurance applications[J]. Med Phys, 2023, 50(5): 3137-3147.
[19] 高文超, 王军良, 杨林等. 国产XHA1400加速器的剂量稳定 性测试[J]. 中国医疗设备, 2021, 36(4): 70-75.
Gao WC, Wang JL, Yang L, et al. Dose stability test of domestic accelerator XHA1400[J]. China Med Devices, 2021, 36(4): 70-75.
[20] 罗斌, 李贤富, 曹璐, 等. Synergy医用加速器3年输出剂量测 量及其稳定性回顾分析[J]. 中国医疗设备, 2022, 37(5): 60-63.
Luo B, Li XF, Cao L, et al. Output dose measurement and stability retrospective analysis of Synergy medical accelerator in 3 years[J]. China Med Devices, 2022, 37(5): 60-63.
[21] 张坤, 李芳, 李雅俊, 等. TrueBeam医用直线加速器性能长期 稳定性评价[J]. 中国医疗设备, 2022, 37(9): 38-41.
Zhang K, Li F, Li YJ, et al. performance evaluation of TrueBeam medical linear accelerator[J]. China Med Devices, 2022, 37(9): 38-41.
[22] International Atomic Energy Agency. Absorbed dose determination in photon and electron beams: an international code of practice[R]. Technical Report Series No.277 (2nd ed in 1997), 1987.
{{custom_fnGroup.title_en}}
Footnotes
{{custom_fn.content}}
PDF(1653 KB)
京公网安备 11010502038061号