Ultrasound-Guided Robotic Needle Steering for Ablation of Liver Cancer

描述(申请人提供)：据估计，2014年美国将诊断出33,190例新的原发性肝癌病例和更多的肝转移癌新病例。根除这些肿瘤可以提高患者的存活率。经皮射频消融(RFA)通过热损伤杀死肿瘤，是一种微创治疗，适用于许多不符合手术切除条件的患者，特别是那些肿瘤类型、位置或大小特定、肝功能不佳或合并其他疾病的患者。然而，技术上的限制阻碍了RFA作为消除肝脏肿瘤的一种手段的广泛采用。由于RFA电极目前采用的直线路径将横跨血管、肺或其他敏感结构，因此无法进入肝脏某些部分的肿瘤。大型肿瘤需要插入多个电极；在患有晚期肝病或严重合并症的患者中，每次穿透肝脏被膜增加的出血风险可能太大。这项工作的长期目标是在使用机器人辅助针头转向的经皮肝脏RFA过程中显著提高通路、准确性和精确度。以下具体目标将推动这项技术的开发，并证明其可行性，作为临床采用的途径：具体目标1：优化基于超声波的高度弯曲针头定位和机器人针头转向的闭环控制。具体目标2：开发交互式用户控制界面，实现远程操控针灸干预。具体目标3：设计一种临床机器人辅助的经皮肝脏RFA针头转向系统，并在体外肝脏模型中得到验证。具体目标4：在活体猪肝脏中验证超声引导的针头转向系统。针转向使高度灵活的针或导丝能够沿着受控的、弯曲的、通过组织的3D路径插入。因此，针可以被主动引导以获得直线路径无法到达的肿瘤，并且随着针向肿瘤前进，可以纠正与所需路径的意外偏差。适合活体实验的功能性针头转向系统必须与广泛使用的医学成像(这里是超声成像)兼容，具有提供治疗的能力(这里是通过使用可转向的针电极进行RFA)，以及适当的用户界面，包括可视化和人在环远程操作。这项技术可以将RFA的生存优势扩展到那些本来可能没有好的治疗选择的患者，从长远来看，可以用于准确放置诊断设备和治疗其他器官的疾病。

DESCRIPTION (provided by applicant): An estimated 33,190 new cases of primary liver cancer and an even larger number of new cases of metastatic cancer to the liver will be diagnosed in the United States in 2014. Eradicating those tumors improves patient survival. Percutaneous radiofrequency ablation (RFA), which kills tumors via thermal damage, is a minimally invasive treatment appropriate for the many patients who are not eligible for surgical resection, particularly those with certain tumor type, location, or size; poor liver function; or oher comorbidities. However, technical limitations have precluded broader adoption of RFA as a means of eliminating liver tumors. Tumors in some portions of the liver cannot be accessed because the straight paths currently taken by RFA electrodes would traverse vasculature, lung, or other sensitive structures. Large tumors require multiple electrode insertions; the increased bleeding risk with each puncture through the liver capsule can be too great in patients with advanced liver disease or severe comorbidities. The long-term goal of this work is to significantly improve access, accuracy, and precision during percutaneous liver RFA procedures using robot-assisted needle steering. The following specific aims will enable the development of this technology and demonstrate feasibility, as a path to clinical adoption: Specific Aim 1: Optimize ultrasound-based localization of highly curved needles and closed-loop control of robotic needle steering. Specific Aim 2: Develop an interactive user control interface and enable teleoperated needle steering intervention. Specific Aim 3: Design a clinical robot-assisted needle steering system for percutaneous liver RFA, validated in an ex vivo liver model. Specific Aim 4: Validate the ultrasound-guided needle steering system in vivo in porcine liver. Needle steering enables the insertion of highly flexible needles or guidewires along controlled, curved, 3D paths through tissue. Thus, the needle can be actively steered to acquire tumors not accessible by a straight- line path, and unexpected deviations from the desired path can be corrected as the needle advances toward the tumor. A functional needle steering system appropriate for in vivo experimentation must be compatible with widely available medical imaging (here, ultrasound imaging), have the ability to deliver treatment (here, RFA through the use of a steerable needle electrode), and an appropriate user interface including visualization and human-in-the-loop teleoperation. This technology could extend the survival advantages of RFA to patients who may otherwise not have good treatment options, and in the long term, be used for accurate placement of diagnostic devices and treatment of diseases in other organs.