论文标题
质子SBRT闪光治疗计划的集成生物学优化框架允许使用患者特异性脊过滤器的剂量，剂量率和优化
An Integrated Biological Optimization framework for proton SBRT FLASH treatment planning allows dose, dose rate, and LET optimization using patient-specific ridge filters
论文作者
论文摘要
目的：特异性脊过滤器可以调节质子能量以获得共形剂量。我们描述了一个新的框架，以优化过滤器设计和点地图，以满足Flash放射疗法的独特需求。我们展示了一种综合的生物优化IMPT（IBO-IMPT）方法，用于优化剂量，剂量平均剂量速率（DADR）和剂量平均LET（LETD）。方法：我们开发了逆计划软件来设计特定于患者的脊过滤器，该软件将布拉格峰从固定能量的250 MEV梁传播到近端梁特异性的计划目标体积。该软件优化了患者特定的脊过滤器，并使用基于Geant4的蒙特卡洛计算引擎提供剂量并让矩阵影响矩阵。使用Matrad的计划优化可容纳IBO-IMPT目标函数，考虑剂量，剂量率，并同时使用最小的MU约束。该框架可以设计定期间隔和稀疏优化的山脊过滤器，从而可以更快地交付和选择性优化。使用特定于心脏和肺部的评估结构比较剂量，DADR和LETD的体积分布和直方图。结果：我们使用IBO-Impt为中央肺肿瘤患者设计脊过滤器。与IMPT计划相对于IMPT计划，IBO-IMPT框架通过降低剂量并提高剂量率有选择性地幸免于心脏和肺部。稀疏优化的山脊过滤器优于定期间隔的山脊过滤器，剂量速率优于。这些创新共同增加了心脏和肺的DADR，同时保持良好的目标覆盖范围。接受闪光剂量较高40 Gy/秒的闪光剂量的体积增加了31％，肺部增加了50％。结论：这项概念验证研究表明，使用IBO-IMPT框架完成质子闪光灯SBPT，同时考虑剂量，DADR和ledd的可行性。
Purpose: Patient-specific ridge filters can modulate proton energy to obtain a conformal dose. We describe a new framework for optimization of filter design and spot maps to meet the unique demands of FLASH radiotherapy. We demonstrate an Integrated Biological Optimization IMPT (IBO-IMPT) approach for optimization of dose, dose-averaged dose rate (DADR), and dose-averaged LET (LETd). Methods: We developed inverse planning software to design patient-specific ridge filters that spread the Bragg peak from a fixed-energy, 250 MeV beam to a proximal beam-specific planning target volume. The software optimizes patient-specific ridge filter and uses a Monte Carlo calculation engine, based on Geant4, to provide dose and LET influence matrices. Plan optimization, using matRAD, accommodates the IBO-IMPT objective function considering dose, dose rate, and LET simultaneously with minimum MU constraints. The framework enables design of both regularly spaced and sparse-optimized ridge filters, which allow faster delivery and selective LET optimization. Volume distributions and histograms for dose, DADR, and LETd are compared using evaluation structures specific to the heart and lung. Results: We used IBO-IMPT to design ridge filters for a central lung tumor patient. The IBO-IMPT framework selectively spared heart and lung by reducing LET and increasing dose rate, relative to IMPT planning. Sparse-optimized ridge filters were superior to regularly spaced ridge filters in dose rate. Together, these innovations substantially increased the DADR in the heart and lung while maintaining good target coverage. The volume that received a FLASH dose rate of higher 40 Gy/second increased by 31% for heart and 50% for lung. Conclusion: This proof-of-concept study demonstrates the feasibility of using an IBO-IMPT framework to accomplish proton FLASH SBPT, accounting for dose, DADR, and LETd simultaneously.
