目的:日本临床肿瘤学组放射治疗研究小组的医学物理工作组目前正在开发一种用于调强放射治疗剂量学认证的虚拟审计系统。目标剂量计包括胶片和阵列探测器,如ArcCHECK(太阳核公司,墨尔本,佛罗里达,美国)和Delta4(ScandiDos,乌普萨拉,瑞典)。这项试点研究使用先前获得的数据调查了我们的虚拟审计系统的可行性。
方法:我们分析了46个薄膜(轴向和冠状平面中的32和14,分别)来自29个机构。测量和计划剂量分布之间的全局伽马分析使用以下设置:3%/3毫米标准(剂量分母为2Gy),30%阈值剂量,不缩放数据集,和90%的公差水平。此外,从9个机构获得了21个数据集用于阵列评估。五个机构使用了ArcCHECK,而其他人则使用Delta4。采用3%/2mm标准(剂量分母为最大计算剂量)进行全局伽马分析,10%阈值剂量,和95%的公差水平。使用使用Python(版本3.9.2)开发的内部软件进行胶片校准和伽马分析。
结果:伽马通过率的平均值±标准偏差为99.4±1.5%(范围,92.8%-100%)和99.2±1.0%(范围,97.0%-100%)在胶片和阵列评估中,分别。
结论:这项试点研究证明了虚拟审计的可行性。拟议的虚拟审计系统将有助于提高效率,更便宜,比现场和邮政审计更快速的试验认证;然而,在操作我们的虚拟审计系统时,应考虑这些限制。
OBJECTIVE: The Medical Physics Working Group of the Radiation Therapy Study Group at the Japan Clinical Oncology Group is currently developing a virtual audit system for intensity-modulated radiation therapy dosimetry credentialing. The target dosimeters include films and array detectors, such as ArcCHECK (Sun Nuclear Corporation, Melbourne, Florida, USA) and Delta4 (ScandiDos, Uppsala, Sweden). This pilot study investigated the feasibility of our virtual audit system using previously acquired data.
METHODS: We analyzed 46 films (32 and 14 in the axial and coronal planes, respectively) from 29 institutions. Global gamma analysis between measured and planned dose distributions used the following settings: 3%/3 mm criteria (the dose denominator was 2 Gy), 30% threshold dose, no scaling of the datasets, and 90% tolerance level. In addition, 21 datasets from nine institutions were obtained for array evaluation. Five institutions used ArcCHECK, while the others used Delta4. Global gamma analysis was performed with 3%/2 mm criteria (the dose denominator was the maximum calculated dose), 10% threshold dose, and 95% tolerance level. The film calibration and gamma analysis were conducted with in-house software developed using Python (version 3.9.2).
RESULTS: The means ± standard deviations of the gamma passing rates were 99.4 ± 1.5% (range, 92.8%-100%) and 99.2 ± 1.0% (range, 97.0%-100%) in the film and array evaluations, respectively.
CONCLUSIONS: This pilot study demonstrated the feasibility of virtual audits. The proposed virtual audit system will contribute to more efficient, cheaper, and more rapid trial credentialing than on-site and postal audits; however, the limitations should be considered when operating our virtual audit system.