Long-term stability of a three-dimensional dose verification system.
Long-term stability of a three-dimensional dose verification system.
复制标题
三维剂量验证系统的长期稳定性。
DOI：
10.1007/s12194-020-00554-7
复制
发表时间：
2020
影响因子：
1.6
通讯作者：
Wataru Sugimoto and Kenta Kitagawa
中科院分区：
文献类型：
--
作者：
Motoharu Sasaki;Hitoshi Ikushima;Wataru Sugimoto and Kenta Kitagawa
近年来，随着适应部位的扩大，接受调强放射治疗和容积调强弧治疗的患者数量也在增加。然而，有必要提高耗时的剂量验证的效率。因此，患者特定的质量保证，预计将从使用传统的电离室剂量计和电影的剂量验证转移到三维剂量验证系统。然而，在使用三维剂量验证系统时需要谨慎，特别是在涉及到探测器的校准时。定期进行校准，但并非所有必要的验证都是例行进行的。三维剂量验证系统的灵敏度如何随时间变化存在许多不确定性。在本研究中，在同一天，当使用三维系统对一个头颈部病例进行剂量验证时，还使用常规电离室剂量计和胶片每两个月进行一次剂量验证，持续2年。从使用电离室剂量计和Gafchromic薄膜的绝对剂量和剂量分布验证的结果，确保了直线加速器的输出、机械准确度和精密度。从三维剂量验证系统的结果来看，当在2 mm和3 mm处评价一致距离，并在2 mm/2%和3 mm/3%处进行伽马分析时，通过率几乎为100%，并且未观察到2年内的灵敏度变化。
Recently, the number of patients undergoing intensity-modulated radiation therapy and volumetric modulated arc therapy has increased with the expansion of the adaptation site. However, it is necessary to improve the efficiency of time-consuming dose verification. Therefore, patient-specific quality assurance is expected to shift from dose verification using a conventional ionization chamber dosimeter and film to a three-dimensional dose verification system. However, caution is required when using a three-dimensional dose verification system, especially when it comes to the calibration of the detector. Calibration is performed regularly, but not all necessary verifications are done routinely. There are many uncertainties on how the sensitivity of the three-dimensional dose verification system changes over time. In this study, on the same day, when dose verification using a three-dimensional system for one head and neck case was performed, dose verification using a conventional ionization chamber dosimeter and film was also performed once every two months, for 2 years. From the results of the absolute dose and dose distribution verification using the ionization chamber dosimeter and Gafchromic film, the output of the linear accelerator, mechanical accuracy and precision were secured. From the results of the three-dimensional dose verification system, when the distance to agreement was evaluated at 2 mm and 3 mm, and gamma analysis was performed at 2 mm/2% and 3 mm/3%, the passing rate was almost 100%, and a sensitivity change in 2 years was not observed.