Department of BioMechanical Engineering, Delft University of Technology, Delft, The Netherlands.
Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Centre Rotterdam, Rotterdam, The Netherlands.
Phys Med Biol. 2024 Nov 25;69(23). doi: 10.1088/1361-6560/ad8b08.
Patient-tailored intracavitary/interstitial (IC/IS) brachytherapy (BT) applicators may increase dose conformity in cervical cancer patients. Current configuration planning methods in these custom applicators rely on manual specification or a small set of (straight) needles. This work introduces and validates a two-stage approach for establishing channel configurations in the 3D printed patient-tailored ARCHITECT applicator.For each patient, the patient-tailored applicator shape was based on the first BT application with a commercial applicator and integrated connectors to a commercial (Geneva) intrauterine tube and two lunar ring channels. First, a large candidate set was generated of channels that steer the needle to desired poses in the target region and are contained in the applicator. The channels' centrelines were represented by Bézier curves. Channels running between straight target segments and entry points were optimised and refined to ensure (dynamic) feasibility. Second, channel configurations were selected using geometric coverage optimisation. This workflow was applied to establish patient-tailored geometries for twenty-two patients previously treated using the Venezia applicator. Treatment plans were automatically generated using the in-house developed algorithm BiCycle. Plans for the clinically used configuration,TPclin, and patient-tailored configuration,TParch, were compared.Channel configurations could be generated in clinically feasible time (median: 2651 s, range 1826-3812 s). AllTParchandTPclinplans were acceptable, but planning aims were more frequently attained with patient-tailored configurations (115/132 versus 100/132 instances). Median CTVD98and bladderD2cm3doses significantly improved (p<0.001 andp<0.01 respectively) inTParchplans in comparison withTPclinplans, and in approximately half of the patients dosimetric indices improved.Automated patient-tailored BT channel configuration planning for 3D printed applicators is clinically feasible. A treatment planning study showed that all plans met planning limits for the patient-tailored configurations, and in selected cases improved the plan quality in comparison with commercial applicator configurations.
患者定制的腔内/间质（IC/IS）近距离放射治疗（BT）施源器可以提高宫颈癌患者的剂量适形度。目前，这些定制施源器中的配置规划方法依赖于手动规范或一小部分（直）针。这项工作介绍并验证了一种在 3D 打印的患者定制 ARCHITECT 施源器中建立通道配置的两阶段方法。对于每个患者，基于首次使用商业施源器进行的第一次 BT 应用，将患者定制施源器的形状与商业（日内瓦）宫内管和两个月球环通道集成在一起。首先，生成一个包含在施源器中的、引导针到达目标区域所需位置的大量候选通道集。通道的中心线由贝塞尔曲线表示。优化和细化连接直目标段和入口点之间的通道，以确保（动态）可行性。其次，使用几何覆盖优化选择通道配置。该工作流程应用于为之前使用 Venezia 施源器治疗的二十二名患者建立患者定制的几何形状。使用内部开发的 BiCycle 算法自动生成治疗计划。比较了临床使用的配置（TPclin）和患者定制的配置（TParch）的计划。可以在临床可行的时间内生成通道配置（中位数：2651 秒，范围 1826-3812 秒）。所有的 TParch 和 TPclin 计划都是可以接受的，但使用患者定制的配置时，计划目标更频繁地实现（115/132 与 100/132 实例）。与 TPclin 计划相比，TParch 计划中 CTVD98 和膀胱 D2cm3 剂量显著改善（p<0.001 和 p<0.01），并且大约一半的患者剂量学指标得到改善。对于 3D 打印施源器，自动化的患者定制 BT 通道配置规划在临床上是可行的。一项治疗计划研究表明，所有计划都满足了患者定制配置的计划限制，并且在某些情况下与商业施源器配置相比，提高了计划质量。
