Biophysics, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany.
Department of Electrical Engineering and Information Technology, TU Darmstadt, Darmstadt, Germany.
Phys Med Biol. 2024 Sep 30;69(20). doi: 10.1088/1361-6560/ad7d59.
. Real-time adaptive particle therapy is being investigated as a means to maximize the treatment delivery accuracy. To react to dosimetric errors, a system for fast and reliable verification of the agreement between planned and delivered doses is essential. This study presents a clinically feasible, real-time 4D-dose reconstruction system, synchronized with the treatment delivery and motion of the patient, which can provide the necessary feedback on the quality of the delivery.. A GPU-based analytical dose engine capable of millisecond dose calculation for carbon ion therapy has been developed and interfaced with the next generation of the dose delivery system (DDS) in use at Centro Nazionale di Adroterapia Oncologica (CNAO). The system receives the spot parameters and the motion information of the patient during the treatment and performs the reconstruction of the planned and delivered 4D-doses. After each iso-energy layer, the results are displayed on a graphical user interface by the end of the spill pause of the synchrotron, permitting verification against the reference dose. The framework has been verified experimentally at CNAO for a lung cancer case based on a virtual phantom 4DCT. The patient's motion was mimicked by a moving Ionization Chamber (IC) 2D-array.. For the investigated static and 4D-optimized treatment delivery cases, real-time dose reconstruction was achieved with an average pencil beam dose calculation speed up to more than one order of magnitude smaller than the spot delivery. The reconstructed doses have been benchmarked against offline log-file based dose reconstruction with the TRiP98 treatment planning system, as well as QA measurements with the IC 2D-array, where an average gamma-index passing rate (3%/3 mm) of 99.8% and 98.3%, respectively, were achieved.. This work provides the first real-time 4D-dose reconstruction engine for carbon ion therapy. The framework integration with the CNAO DDS paves the way for a swift transition to the clinics.
. 实时自适应粒子治疗正被研究作为提高治疗精度的手段。为了应对剂量学误差，需要建立一个快速可靠的系统来验证计划剂量与实际剂量之间的一致性。本研究提出了一种临床可行的、与治疗同步的实时 4D 剂量重建系统，它可以与正在使用的 Centro Nazionale di Adroterapia Oncologica（CNAO）的下一代剂量输送系统（DDS）同步，为治疗提供反馈。该系统接收治疗过程中的点参数和患者运动信息，并对计划的和输送的 4D 剂量进行重建。在每个等能层之后，在同步加速器的束流暂停结束时，通过图形用户界面显示结果，与参考剂量进行验证。该框架已在 CNAO 进行了肺癌病例的实验验证，该病例基于虚拟 4DCT 体模。通过移动电离室（IC）2D 阵列来模拟患者的运动。对于研究的静态和 4D 优化治疗输送情况，实时剂量重建的平均铅笔束剂量计算速度比点输送速度快一个数量级以上。重建的剂量已与基于离线日志文件的 TRiP98 治疗计划系统的剂量重建以及与 IC 2D 阵列的 QA 测量进行了基准测试，平均伽马指数通过率（3%/3mm）分别达到了 99.8%和 98.3%。这项工作为碳离子治疗提供了第一个实时 4D 剂量重建引擎。与 CNAO DDS 的框架集成为快速过渡到临床铺平了道路。
