论文标题
与质子闪光放射疗法的传输梁和单能扩散峰的混合逆计划的可行性研究
Feasibility Study of Hybrid Inverse Planning with Transmission Beams and Single-energy Spread-out Bragg Peaks for Proton Flash Radiotherapy
论文作者
论文摘要
超高剂量速率（闪光灯）质子规划只有传输梁（TBS）在正常组织的限制中受到限制。闪光剂量速率的单能扩张峰值（sesobps）对于质子闪光计划已证明是可行的。开发了一种混合反向优化方法，以将TBS和Sesobps（TB-Sesobp）结合起来进行闪存计划。通过预先设计的一般条脊过滤器将BPS散布而产生，并通过范围变速杆放置在中心目标，以获得目标内的均匀剂量。 sesobps和tbs被完全采样逐场，以在优化过程中自动选择和加权。与仅与结核病计划相比，TB-SESOBP计划得到了验证，以及与TBS和BPS（TB-BP）结合的计划，就五个肺部病例的3D剂量和剂量率分布组合。与仅使用TB计划相比，平均脊髓D1.2CC急剧降低了41％，平均肺V7GY和V7.4GY中度降低了17％，目标剂量同质性在TB-SesOBP计划中略有增加。在TB-SesOBP和TB-BP计划中都达到了可比的剂量同质性。此外，与TB-BP计划相比，TB-SESOBP计划对肺部相对较大的目标的肺部进行了显着改善。在所有三个计划中，目标都被闪光剂量率完全覆盖。对于桨，v40gy/s = 100％是仅由TB的计划实现的，而其他两个计划获得了V40GY/S> 85％。我们已经证明，混合TB-SesOBP计划是可行的，可以实现质子治疗的闪光剂量率。混合TB-SesOBP计划在维持高靶剂量同质性的同时改善OAR保留方面具有巨大的潜力，并且可以实施适应性放射疗法。
Ultra-high dose rate (FLASH) proton planning with only transmission beams (TBs) has limitations in normal tissue sparing. The single-energy spread-out Bragg peaks (SESOBPs) of FLASH dose rate have been demonstrated feasible for proton FLASH planning. A hybrid inverse optimization method was developed to combine the TBs and SESOBPs (TB-SESOBP) for FLASH planning. The SESOBPs were generated from spreading out the BPs by pre-designed general bar ridge filters and placed at the central target by range shifters to obtain a uniform dose within the target. The SESOBPs and TBs were fully sampled field-by-field allowing automatic spot selection and weighting in the optimization process. The TB-SESOBP plans were validated in comparison with the TB only (TB-only) plans and the plans with the combination of TBs and BPs (TB-BP) regarding 3D dose and dose rate distributions for five lung cases. Comparing to the TB-only plans, the mean spinal cord D1.2cc drastically reduced 41%, the mean lung V7Gy and V7.4Gy moderately reduced by up to 17% and the target dose homogeneity slightly increased in the TB-SESOBP plans. Comparable dose homogeneity was achieved in both TB-SESOBP and TB-BP plans. Besides, prominent improvements were achieved in lung sparing for the cases of relatively large targets by the TB-SESOBP plans comparing to the TB-BP plans. The targets were fully covered with the FLASH dose rate in all the three plans. For the OARs, V40Gy/s = 100% was achieved by the TB-only plans while V40Gy/s > 85% was obtained by the other two plans. We have demonstrated that the hybrid TB-SESOBP planning was feasible to achieve FLASH dose rate for proton therapy. The hybrid TB-SESOBP planning has great potential in improving OAR sparing while maintaining high target dose homogeneity, and can be potentially implemented for adaptive radiotherapy.
