Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
Faculty of Physics and Astronomy, Heidelberg University, Heidelberg, Germany.
Phys Med Biol. 2024 Jun 17;69(12). doi: 10.1088/1361-6560/ad46db.
Recently, a new and promising approach for range verification was proposed. This method requires the use of two different ion species. Due to their equal magnetic rigidity, fully ionized carbon and helium ions can be simultaneously accelerated in accelerators like synchrotrons. At sufficiently high treatment energies, helium ions can exit the patient distally, reaching approximately three times the range of carbon ions at an equal energy per nucleon. Therefore, the proposal involves adding a small helium fluence to the carbon ion beam and utilizing helium as an online range probe during radiation therapy. This work aims to develop a software framework for treatment planning and motion verification in range-guided radiation therapy using mixed carbon-helium beams.The developed framework is based on the open-source treatment planning toolkit matRad. Dose distributions and helium radiographs were simulated using the open-source Monte Carlo package TOPAS. Beam delivery system parameters were obtained from the Heidelberg Ion Therapy Center, and imaging detectors along with reconstruction were facilitated by ProtonVDA. Methods for reconstructing the most likely patient positioning error scenarios and the motion phase of 4DCT are presented for prostate and lung cancer sites.The developed framework provides the capability to calculate and optimize treatment plans for mixed carbon-helium ion therapy. It can simulate the treatment process and generate helium radiographs for simulated patient geometry, including small beam views. Furthermore, motion reconstruction based on these radiographs seems possible with preliminary validation.The developed framework can be applied for further experimental work with the promising mixed carbon-helium ion implementation of range-guided radiotherapy. It offers opportunities for adaptation in particle therapy, improving dose accumulation, and enabling patient anatomy reconstruction during radiotherapy.
最近，一种新的、有前途的射程验证方法被提出来。该方法需要使用两种不同的离子种类。由于它们的磁刚度相等，完全电离的碳离子和氦离子可以在同步加速器等加速器中同时被加速。在足够高的处理能量下，氦离子可以从患者的远端逸出，在相同的每核子能量下，其射程约为碳离子的三倍。因此，该建议涉及在碳离子束中添加少量的氦离子，并在放射治疗期间利用氦作为在线射程探测器。这项工作旨在开发一个用于混合碳-氦束引导放射治疗的治疗计划和运动验证的软件框架。所开发的框架基于开源治疗计划工具包 matRad。使用开源蒙特卡罗包 TOPAS 模拟了剂量分布和氦射线照片。束流输送系统参数来自海德堡离子治疗中心，成像探测器以及重建由 ProtonVDA 提供。提出了用于重建最可能的患者定位误差场景和 4DCT 运动相位的方法，适用于前列腺癌和肺癌部位。所开发的框架提供了计算和优化混合碳-氦离子治疗计划的能力。它可以模拟治疗过程，并为模拟患者几何形状生成氦射线照片，包括小射束视图。此外，基于这些射线照片进行运动重建似乎是可行的，并且已经进行了初步验证。所开发的框架可应用于具有前途的混合碳-氦离子实现的范围引导放射治疗的进一步实验工作。它为粒子治疗中的适应性改进、剂量积累的提高以及在放射治疗期间实现患者解剖结构重建提供了机会。
