Abstract：
This study aimed to determine the dosimetric value of flattening filter-free (FFF) beams compared to flattening filter (FF) beams using different algorithms in the treatment planning of thoracic spine stereotactic body radiation therapy (SBRT). A total of 120 plans were created for 15 patients using the Anisotropic Analytical Algorithm (AAA) and the Acuros External Beam (AXB) algorithm with FF and FFF beams at 6 MV and 10 MV energies. Various dosimetric parameters were evaluated, including target coverage, dose spillage, and organs-at-risk sparing of the spinal cord and esophagus. Treatment delivery parameters, such as the monitor units (MUs), modulation factors (MFs), beam-on time (BOT), and dose calculation time (DCT), were also collected. Significant differences were observed in the dosimetric parameters when AXB was used for all energies (P < 0.05). 6 XFFF energy was the best option for target coverage, dose spillage, and organs-at-risk sparing. In contrast, dosimetric parameters had no significant difference when using the AAA. The AAA and AXB calculations showed that the 6 XFFF beam had the shortest DCT. The treatment delivery parameters indicated that 10 XFF beam required the fewest MUs and MFs. In addition, the 10 XFFF beam demonstrated the shortest BOT. For effective treatment of the thoracic spine using SBRT, it is recommended to use the 10 XFFF beam because of the short BOT. Moreover, the AXB algorithm should be used because of its accurate dose calculation in regions with tissue heterogeneity.
摘要：
这项研究旨在确定在胸椎立体定向身体放射治疗（SBRT）的治疗计划中使用不同算法的平坦无滤波器（FFF）束与平坦滤波器（FF）束相比的剂量测定值。使用各向异性分析算法（AAA）和Acuros外部光束（AXB）算法，在6MV和10MV能量下使用FF和FFF光束，为15名患者创建了总共120个计划。评估了各种剂量学参数，包括目标覆盖范围，剂量溢出,以及保留脊髓和食道的危险器官。治疗输送参数,如监测单元(MU)，调制因子(MF)，开束时间(BOT)，和剂量计算时间（DCT），也被收集了。当AXB用于所有能量时,观察到剂量学参数的显著差异(P<0.05)。6XFFF能量是目标覆盖的最佳选择，剂量溢出,和器官的风险节省。相比之下,使用AAA时，剂量学参数没有显着差异。AAA和AXB计算表明6XFFF波束具有最短的DCT。治疗递送参数表明10个XFF波束需要最少的MU和MF。此外,10XFFF梁显示了最短的BOT。为了使用SBRT有效治疗胸椎，建议使用10XFFF梁，因为BOT较短。此外，由于AXB算法在具有组织异质性的区域中具有精确的剂量计算,因此应该使用该算法。
