Department of Radiation Oncology, Radiation Oncology, University of Kansas Medical Center, Kansas City, Kansas, USA.
Med Phys. 2023 Jun;50(6):3311-3323. doi: 10.1002/mp.16297. Epub 2023 Feb 26.
Hybrid proton-photon radiotherapy (RT) can provide better plan quality than proton or photon only RT, in terms of robustness of target coverage and sparing of organs-at-risk (OAR).
This work develops a hybrid treatment planning method that can optimize the number of proton and photon fractions as well as proton and photon plan variables, so that the hybrid plans can be clinically delivered day-to-day using either proton or photon machine.
In the new hybrid treatment planning method, the total dose distribution (sum of proton dose and photon dose) is optimized for robust target coverage and optimal OAR sparing, by jointly optimizing proton spots and photon fluences, while the target dose uniformity is also enforced individually on both proton dose and photon dose, so that the hybrid plans can be separately and robustly delivered on proton or photon machine. To ensure the target dose uniformity for proton and photon plans, the number of proton and photon fractions is explicitly modeled and optimized, so that the target dose for proton and photon dose components is constrained to be a constant fraction of the total prescription dose while the plan quality based on total dose is optimized. The feasibility of hybrid planning using the proposed method is validated with representative clinical cases including abdomen, lung, head-and-neck (HN), and brain.
For all cases, hybrid plans provided better overall plan quality and OAR sparing than proton-only or photon-only plans, better target dose uniformity and robustness than proton-only plans, quantified by treatment planning objectives and dosimetric parameters. Moreover, for HN and brain cases, hybrid plans also had better target coverage than photon-only plans.
We have developed a new hybrid treatment planning method that optimizes number of proton and photon fractions as well as proton spots and photon fluences, for generating hybrid plans that can be separately and robustly delivered on proton or photon machines. Preliminary results have demonstrated that hybrid plans generated by the new method have better plan quality than proton-only or photon-only plans.
与质子或光子放疗相比，混合质子-光子放疗（RT）在靶区覆盖的稳健性和危及器官（OAR）的保护方面能够提供更好的计划质量。
本研究开发了一种混合治疗计划方法，该方法可以优化质子和光子的分割次数以及质子和光子的计划变量，以便可以使用质子或光子机器每天临床交付混合计划。
在新的混合治疗计划方法中，通过联合优化质子点和光子通量，优化总剂量分布（质子剂量和光子剂量之和），以实现稳健的靶区覆盖和最佳的 OAR 保护，同时也分别对质子剂量和光子剂量强制执行靶区剂量均匀性，以使质子或光子机器都可以分别稳健地交付混合计划。为了确保质子和光子计划的靶区剂量均匀性，明确地对质子和光子的分割次数进行建模和优化，使得质子和光子剂量分量的靶区剂量被约束为总处方剂量的恒定分数，同时优化基于总剂量的计划质量。通过使用所提出的方法对包括腹部、肺部、头颈部（HN）和脑部的代表性临床病例进行验证，证明了混合计划的可行性。
对于所有病例，与质子放疗或光子放疗相比，混合计划提供了更好的整体计划质量和 OAR 保护，与质子放疗相比，更好的靶区剂量均匀性和稳健性，通过治疗计划目标和剂量学参数进行量化。此外，对于 HN 和脑部病例，混合计划的靶区覆盖率也优于光子放疗计划。
我们已经开发了一种新的混合治疗计划方法，该方法优化了质子和光子的分割次数以及质子点和光子通量，以生成可以分别在质子或光子机器上稳健交付的混合计划。初步结果表明，新方法生成的混合计划质量优于质子放疗或光子放疗计划。
