Shiau An-Cheng, Hsu Shih-Ming, Huang Pei-Yun, Chen Chiu-Ping, Huang Yi-Ting, Lien Ke-Yu, Chen Chin-Ping, Fan Shung-Hwei, Jeng Shiu-Chen, Chen Ho-Hsing, Liang Ji-An
Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan.
Department of Radiation Oncology, Taoyuan Armed Forces General Hospital, Taoyuan, Taiwan.
BJR Open. 2021 Apr 15;3(1):20210002. doi: 10.1259/bjro.20210002. eCollection 2021.
This study examines the practice of the regulation of Standards for Medical Exposure Quality Assurance (SMEQA) in Taiwan based on on-site quality audit for radiation therapy systems from 2016 to 2019.
81 radiation therapy departments, 141 linacs, 9 γ knife systems, 34 high dose rate brachytherapy systems, 20 Tomotherapys, and 6 Cyberknives were audited yearly. Data collection and analysis for each institute's documents including QA procedure, ion chamber and electrometer calibration reports, and a questionnaire relating to machine type and staffing, were requested first and reviewed by auditors. On-site SMEQA core item measurements, including beam output, beam profile and energy constancy for external beam therapy systems, and the source strength, positioning, and timer accuracy for brachytherapy systems were audited second. More than 300 photon beams and more than 400 electron beams were measured each year.
There were approximately 8.9 radiotherapy units per million population, and 1.2 medical physicists per unit in Taiwan. For the output measurements, more than 78 and 75% of the photon beams and electron beams, respectively, from linacs were with deviations within ±1.0%. Photon beams have lower beam quality measurement deviations than electron beams. Including in-plane and cross-plane measurements, more than 90 and 85% photon and electron beams, respectively, were with flatness consistency within 1.0%. All audit measurements were within the SMEQA acceptance criteria.
According to SMEQA regulations on-site QA audits were successfully carried out from 2016 to 2019 for all Taiwan radiotherapy units. The measurement results showed high quality machine performance in Taiwan.
Dosimetry audits with directly acquired measurement readings have lower uncertainties; allow immediate feedback, discussion, and adjustment in a timely manner. In addition to regulation system establishment and education and training implementation, the machine quality is closely related to machine maintenance implementation.
本研究基于2016年至2019年对放射治疗系统的现场质量审核，考察台湾地区医学照射质量保证标准（SMEQA）的监管实践。
每年对81个放射治疗科室、141台直线加速器、9套伽马刀系统、34套高剂量率近距离放射治疗系统、20台螺旋断层放射治疗系统和6台射波刀进行审核。首先要求各机构提供包括质量保证程序、电离室和静电计校准报告以及与机器类型和人员配备相关的问卷等文件进行数据收集和分析，并由审核人员进行审查。其次对SMEQA核心项目进行现场测量，包括外照射治疗系统的射束输出、射束轮廓和能量稳定性，以及近距离放射治疗系统的源强度、定位和定时器精度。每年测量超过300个光子束和超过400个电子束。
台湾地区每百万人口约有8.9个放射治疗单元，每个单元有1.2名医学物理师。对于输出测量，直线加速器的光子束和电子束分别有超过78%和75%的偏差在±1.0%以内。光子束的射束质量测量偏差低于电子束。包括平面内和平面交叉测量，分别有超过90%的光子束和85%的电子束平整度一致性在1.0%以内。所有审核测量均符合SMEQA验收标准。
根据SMEQA规定，2016年至2019年对台湾所有放射治疗单元成功进行了现场质量保证审核。测量结果显示台湾地区机器性能质量较高。
直接获取测量读数的剂量学审核不确定性较低；允许及时反馈、讨论和调整。除了建立监管体系和开展教育培训外，机器质量与机器维护的实施密切相关。
