Department of Biophysics, Faculty of Science, Cairo University, Cairo, Egypt; Department of Radiotherapy, Baheya center for early detection and treatment of breast cancer, Giza, Egypt.
Department of Radiotherapy, Baheya center for early detection and treatment of breast cancer, Giza, Egypt.
Med Dosim. 2024;49(3):232-238. doi: 10.1016/j.meddos.2024.01.005. Epub 2024 Feb 8.
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.
本研究旨在比较不同算法在胸脊柱立体定向体部放射治疗（SBRT）计划中的剂量学价值，使用非各向同性分析算法（AAA）和 Acuros 外部射束（AXB）算法，比较 6MV 和 10MV 能量下的常规射束（FF）和均整射束（FFF）。共为 15 名患者创建了 120 个计划。评估了各种剂量学参数，包括靶区覆盖、剂量外溢和脊髓、食管等危及器官的保护。还收集了治疗输送参数，如监测单位（MU）、调制因子（MF）、射束开启时间（BOT）和剂量计算时间（DCT）。当使用 AXB 时，所有能量的剂量学参数都有显著差异（P < 0.05）。6 XFFF 能量是靶区覆盖、剂量外溢和保护危及器官的最佳选择。相比之下，使用 AAA 时，剂量学参数没有显著差异。AAA 和 AXB 计算表明，6 XFFF 射线具有最短的 DCT。治疗输送参数表明，10 XFF 射线需要的 MU 和 MF 最少。此外，10 XFFF 射线的 BOT 最短。对于使用 SBRT 有效治疗胸脊柱，建议使用 10 XFFF 射线，因为其 BOT 较短。此外，由于 AXB 算法在组织异质性区域具有准确的剂量计算，因此应使用 AXB 算法。
