College of Business, Coppin State University, Baltimore, Maryland, USA.
University of Maryland Medical Systems, Linthicum, Maryland, USA.
J Appl Clin Med Phys. 2023 Jun;24(6):e13920. doi: 10.1002/acm2.13920. Epub 2023 Feb 2.
To incorporate four-dimensional computed tomography (4DCT)-based ventilation imaging into intensity-modulated radiation therapy (IMRT) treatment planning for pulmonary functional avoidance.
Nineteen locally advanced lung cancer patients are retrospectively studied. 4DCT images are employed to create ventilation maps for each patient via a density-change-based algorithm with mass correction. The regional ventilation is directly incorporated into the mathematical formulation of a direct aperture optimization model in IMRT treatment planning to achieve functional avoidance and a voxel-based treatment plan. The proposed functional avoidance planning and voxel-based planning are compared to the conventional treatment planning approach purely based on the anatomy of patients. Paired sample t-tests are conducted to see whether dosimetric differences among the three approaches are significant.
Similar planning target volume (PTV) coverage is achieved by anatomical, functional avoidance, and voxel-based approaches. The voxel-based treatment planning performs better than both functional avoidance and anatomical planning to the lung. For a total lung, the average volume reductions in a functional avoidance plan from an anatomical plan, a voxel-based plan from an anatomical plan, and a voxel-based plan from a functional avoidance plan are 7.0%, 16.8%, and 10.6%, respectively for V ; and 0.4%, 6.4%, and 6.0%, respectively for mean Lung Dose (MLD). For a functional lung, the reductions are 8.8%, 17.2%, and 9.2%, respectively, for fV ; and 1.1%, 6.2%, and 5.2%, respectively, for functional mean lung dose (fMLD). These reductions are obtained without significantly increasing doses to other organs-at-risk. All the pairwise treatment planning comparisons for both total lung and functional lung are statistically significant (p-value ) except for the functional avoidance plan with the anatomical plan pair in which the p-value . From these results, we can conclude that voxel-based treatment planning outperforms both anatomical and functional-avoidance planning.
We propose a treatment planning framework that directly utilizes functional images and compares voxel-based treatment planning with functional avoidance and anatomical treatment planning.
将基于四维计算机断层扫描（4DCT）的通气成像纳入肺功能回避的调强放疗（IMRT）治疗计划中。
本研究回顾性分析了 19 例局部晚期肺癌患者。通过基于密度变化的算法并结合质量校正，为每位患者创建通气图。区域通气直接纳入 IMRT 治疗计划中的直接孔径优化模型的数学公式中，以实现功能回避和基于体素的治疗计划。将所提出的功能回避计划和基于体素的计划与仅基于患者解剖结构的常规治疗计划方法进行比较。采用配对样本 t 检验来确定这三种方法之间的剂量学差异是否具有统计学意义。
基于解剖结构、功能回避和基于体素的方法均实现了相似的计划靶区（PTV）覆盖。与功能回避和解剖结构计划相比，基于体素的治疗计划对肺的效果更好。对于全肺，功能回避计划相对于解剖计划、基于体素的计划相对于解剖计划、基于体素的计划相对于功能回避计划的平均肺体积减少量分别为 V 为 7.0%、16.8%和 10.6%；平均肺剂量（MLD）分别为 0.4%、6.4%和 6.0%。对于功能肺，fV 分别为 8.8%、17.2%和 9.2%；功能平均肺剂量（fMLD）分别为 1.1%、6.2%和 5.2%。在不显著增加其他危及器官剂量的情况下，获得了这些减少量。对于全肺和功能肺，除了功能回避计划与解剖计划配对的 p 值大于 0.05 之外，所有配对治疗计划比较均具有统计学意义（p 值 ）。从这些结果可以得出结论，基于体素的治疗计划优于解剖和功能回避治疗计划。
我们提出了一种治疗计划框架，该框架直接利用功能图像，并将基于体素的治疗计划与功能回避和解剖治疗计划进行比较。
