Physics Department of University of Aveiro, Aveiro, Portugal.
Medical Physics Department of the Portuguese Oncology Institute of Coimbra Francisco Gentil, EPE, Coimbra, Portugal.
Phys Eng Sci Med. 2021 Dec;44(4):1273-1283. doi: 10.1007/s13246-021-01061-8. Epub 2021 Oct 7.
Two methods for non-coplanar beam direction optimization, one for static beams and another for arc trajectories, were proposed for intracranial tumours. The results of the beam angle optimizations were compared with the beam directions used in the clinical plans. Ten meningioma cases already treated were selected for this retrospective planning study. Algorithms for non-coplanar beam angle optimization (BAO) and arc trajectory optimization (ATO) were used to generate the corresponding plans. A plan quality score, calculated by a graphical method for plan assessment and comparison, was used to guide the beam angle optimization process. For each patient, the clinical plans (CLIN), created with the static beam orientations used for treatment, and coplanar VMAT approximated plans (VMAT) were also generated. To make fair plan comparisons, all plan optimizations were performed in an automated multicriteria calculation engine and the dosimetric plan quality was assessed. BAO and ATO plans presented, on average, moderate global plan score improvements over VMAT and CLIN plans. Nevertheless, while BAO and CLIN plans assured a more efficient OARs sparing, the ATO and VMAT plans presented a higher coverage and conformity of the PTV. Globally, all plans presented high-quality dose distributions. No statistically significant quality differences were found, on average, between BAO, ATO and CLIN plans. However, automated plan solution optimizations (BAO or ATO) may improve plan generation efficiency and standardization. In some individual patients, plan quality improvements were achieved with ATO plans, demonstrating the possible benefits of this automated optimized delivery technique.
针对颅内肿瘤，提出了两种非共面射束方向优化方法，一种用于静态射束，另一种用于弧形轨迹。将优化后的射束角度结果与临床计划中的射束方向进行了比较。选择了 10 例已接受治疗的脑膜瘤病例进行这项回顾性计划研究。使用非共面射束角度优化（BAO）和弧形轨迹优化（ATO）算法生成相应的计划。使用图形方法评估和比较计划的计划质量评分来指导射束角度优化过程。对于每个患者，还生成了使用治疗中静态射束方向创建的临床计划（CLIN）和共面 VMAT 近似计划（VMAT）。为了进行公平的计划比较，所有计划优化都是在自动化多标准计算引擎中进行的，并评估了剂量学计划质量。BAO 和 ATO 计划平均而言，在 VMAT 和 CLIN 计划上的全局计划评分均有适度提高。尽管 BAO 和 CLIN 计划可以更有效地保护 OAR，但 ATO 和 VMAT 计划则可以更好地覆盖和适形 PTV。总体而言，所有计划均具有高质量的剂量分布。平均而言，BAO、ATO 和 CLIN 计划之间未发现具有统计学意义的质量差异。但是，自动化计划解决方案优化（BAO 或 ATO）可能会提高计划生成效率和标准化。在某些个别患者中，ATO 计划可提高计划质量，这表明了这种自动化优化递送技术的潜在益处。
