PDF(Pubmed)
Abstract：
We aimed to investigate the deliverability of dynamic conformal arc therapy (DCAT) by gantry wobble owing to the intrinsic inter-segment break of the Elekta linear accelerator (LINAC) and its adverse influence on the dose to the patient. The deliverability of DCAT was evaluated according to the plan parameters, which affect the gantry rotation speed and resultant positional inaccuracies; the deliverability according to the number of control points and dose rates was investigated by using treatment machine log files and dosimetry devices, respectively. A non-negligible degradation in DCAT deliverability due to gantry wobble was observed in both the treatment machine log files and dosimetry devices. The resulting dose-delivery error occurred below a certain number of control points or above a certain dose rate. Dose simulations in the patient domain showed a similar impact on deteriorated deliverability. For targets located primarily in the isocenter, the dose differences were negligible, whereas for organs at risk located mainly off-isocenter, the dose differences were significant up to - 8.77%. To ensure safe and accurate radiotherapy, optimal plan parameters should be selected, and gantry angle-specific validations should be conducted before treatment.
摘要：
我们旨在研究由于Elekta直线加速器（LINAC）固有的节段间断裂及其对患者剂量的不利影响，通过机架摆动进行动态适形电弧治疗（DCAT）的可执行性。根据计划参数评估DCAT的可交付性，影响机架旋转速度和由此产生的位置不准确性；通过使用治疗机日志文件和剂量测定设备，根据控制点和剂量率的数量研究了可输送性，分别。在治疗机日志文件和剂量测定设备中都观察到由于机架摆动而导致的DCAT可输送性的不可忽略的下降。所产生的剂量输送误差发生在低于一定数量的控制点或高于一定的剂量率。患者领域中的剂量模拟显示对恶化的递送能力的类似影响。对于主要位于等中心的目标，剂量差异可以忽略不计，而对于主要位于等中心的危险器官，剂量差异显著达-8.77%。为了确保安全和准确的放射治疗，应选择最佳计划参数，和机架角度特定的验证应在治疗前进行。
