Characteristics of gated treatment using an optical surface imaging and gating system on an Elekta linac.
Characteristics of gated treatment using an optical surface imaging and gating system on an Elekta linac.
复制标题
DOI：
10.1186/s13014-015-0376-x
复制
发表时间：
2015-03-19
期刊：
影响因子：
--
通讯作者：
Soehn M
中科院分区：
文献类型：
--
作者：
Freislederer P;Reiner M;Hoischen W;Quanz A;Heinz C;Walter F;Belka C;Soehn M
了解门控放疗设备的技术特性对于确保使用深吸气屏气和自由呼吸门控等技术时进行精准治疗至关重要。通过将新型表面成像系统 Catalyst™（C-RAD AB，瑞典）通过 Elekta Response Interface 与 Elekta Synergy 直线加速器（Elekta AB，瑞典）连接的首批安装之一，在我们机构临床实施门控治疗之前，对剂量输送准确性和时间延迟等特性进行了研究。在本研究中，使用移动模型来模拟由 Catalyst™ 系统记录的呼吸运动。门控电平是手动设置的。在此门控窗口内，触发信号会自动发送到直线加速器，启动治疗交付。使用静态 2D 二极管阵列（MapCheck2，Sun Nuclear Co.，美国）记录具有不同选通水平的选通直线加速器治疗光束的剂量测量，并与不同射野尺寸的非选通参考测量进行比较。此外，使用射线照相胶片测量门控治疗光束的时间延迟。门控和非门控治疗之间的剂量递送差异随着所选门控水平的大小而减小。对于约 30% 的临床相关门控水平，剂量输送精度的差异保持在 1% 以下。与文献中的其他系统配置相比，波束开启时间延迟显示出 851 ms±100 ms 的较大偏差。在进行门控治疗时，尤其是自由呼吸门控时，必须根据质量保证流程定期评估时间延迟和剂量输送等因素。一旦知道这些参数，就可以对其进行计算和补偿，例如通过调整预选的门控水平或内部目标体积裕度以及使用呼吸曲线的预测算法。由于此处报告的高光束开启时间延迟，预测算法的使用变得不可避免。
Knowing the technical characteristics of gated radiotherapy equipment is crucial for ensuring precise and accurate treatment when using techniques such as Deep-Inspiration Breath-Hold and gating under free breathing. With one of the first installations of the novel surface imaging system Catalyst™ (C-RAD AB, Sweden) in connection with an Elekta Synergy linear accelerator (Elekta AB, Sweden) via the Elekta Response Interface, characteristics like dose delivery accuracy and time delay were investigated prior to clinical implementation of gated treatments in our institution. In this study a moving phantom was used to simulate respiratory motion which was registered by the Catalyst™ system. The gating level was set manually. Within this gating window a trigger signal is automatically sent to the linac initiating treatment delivery. Dose measurements of gated linac treatment beams with different gating levels were recorded with a static 2D-Diode Array (MapCheck2, Sun Nuclear Co., USA) and compared to ungated reference measurements for different field sizes. In addition, the time delay of gated treatment beams was measured using radiographic film. The difference in dose delivery between gated and ungated treatment decreases with the size of the chosen gating level. For clinically relevant gating levels of about 30%, the differences in dose delivery accuracy remain below 1%. In comparison with other system configurations in literature, the beam-on time delay shows a large deviation of 851 ms ± 100 ms. When performing gated treatment, especially for free-breathing gating, factors as time delay and dose delivery have to be evaluated regularly in terms of a quality assurance process. Once these parameters are known they can be accounted and compensated for, e.g. by adjusting the pre-selected gating level or the internal target volume margins and by using prediction algorithms for breathing curves. The usage of prediction algorithms becomes inevitable with the high beam-on time delay which is reported here.
登录
查看更多内容
影响因子：
2.1
作者：
Cui G;Housley DJ;Chen F;Mehta VK;Shepard DM
通讯作者：
Shepard DM
DOI：
10.1016/j.ijrobp.2009.01.034
发表时间：
2009-07-01
影响因子：
7
作者：
Smith, Ryan L.;Lechleiter, Kristen;Parikh, Parag
通讯作者：
Parikh, Parag
影响因子：
3.5
作者：
Riaz, Nadeem;Shanker, Piyush;Xing, Lei
通讯作者：
Xing, Lei
DOI：
10.1186/1748-717x-8-291
发表时间：
2013-12-20
期刊：
Radiation oncology (London, England)
影响因子：
--
作者：
Gong G;Wang R;Guo Y;Zhai D;Liu T;Lu J;Chen J;Liu C;Yin Y
通讯作者：
Yin Y
DOI：
10.1016/s0360-3016(00)00524-1
发表时间：
2000-07-01
影响因子：
7
作者：
Minohara, S;Kanai, T;Kanazawa, M
通讯作者：
Kanazawa, M