Cervical cancer accounts for a significant portion of the global cancer burden among women. Interstitial brachytherapy (ISBT) is a standard procedure for treating cervical cancer; it involves placing a radioactive source through a straight hollow needle within or in close proximity to the tumor and surrounding tissue. However, the use of straight needles limits surgical planning to a linear needle path. We present the OncoReach stylet, a handheld, tendon-driven steerable stylet designed for compatibility with standard ISBT 15- and 13-gauge needles. Building upon our prior work, we evaluated design parameters like needle gauge, spherical joint count and spherical joint placement, including an asymmetric disk design to identify a configuration that maximizes bending compliance while retaining axial stiffness. Free space experiments quantified tip deflection across configurations, and a two-tube Cosserat rod model accurately predicted the centerline shape of the needle for most trials. The best performing configuration was integrated into a reusable handheld prototype that enables manual actuation. A patient-derived, multi-composite phantom model of the uterus and pelvis was developed to conduct a pilot study of the OncoReach steerable stylet with one expert user. Results showed the ability to steer from less-invasive, medial entry points to reach the lateral-most targets, underscoring the significance of steerable stylets.

翻译：宫颈癌占全球女性癌症负担的显著比例。组织间插植近距离放射治疗（ISBT）是治疗宫颈癌的标准程序，其通过将放射源置于直型空心针内，并将其植入肿瘤及周围组织内部或邻近区域。然而，直型针的使用将手术规划限制于线性针道。本文提出OncoReach导针，一种手持式、肌腱驱动的可操纵导针，设计用于兼容标准的15号和13号ISBT针。基于我们先前的工作，我们评估了针径、球铰数量与球铰位置等设计参数，包括采用非对称圆盘设计以确定在保持轴向刚度的同时最大化弯曲柔顺性的构型。自由空间实验量化了不同构型的针尖偏转，双管Cosserat杆模型准确预测了大多数试验中针的中心线形状。性能最佳的构型被集成至可重复使用的手持式原型机中，实现手动驱动。我们开发了基于患者数据的子宫与骨盆多材料复合体模，由一位专家操作者对OncoReach可操纵导针进行了初步研究。结果表明，该导针能够从创伤较小的内侧入路点进行操纵，抵达最外侧靶区，这凸显了可操纵导针的重要意义。