Department of Electrical Engineering, University of Notre Dame, Notre Dame, IN 46556, USA.
Department of Electrical and Computer Engineering, University of Washington, Seattle, WA 98195, USA.
Sensors (Basel). 2024 Aug 30;24(17):5639. doi: 10.3390/s24175639.
Achieving negative surgical margins, defined as no tumor found on the edges of the resected tissue, during lumpectomy for breast cancer is critical for mitigating the risk of local recurrence. To identify nonpalpable tumors that cannot be felt, pre-operative placements of wire and wire-free localization devices are typically employed. Wire-free localization approaches have significant practical advantages over wired techniques. In this study, we introduce an innovative localization system comprising a light-emitting diode (LED)-based implantable device and handheld system. The device, which is needle injectable and wire free, utilizes multiple wirelessly powered LEDs to provide direct visual guidance for lumpectomy. Two distinct colors, red and blue, provide a clear indication of tissue depth: blue light is absorbed strongly in tissue, visible within a close range of <1 cm, while red light remains visible through several centimeters of tissue. The LEDs, integrated with an impedance-matching circuit and receiver coil, are encapsulated in biocompatible epoxy for injection with a 12 G needle. Our findings demonstrate that the implant exhibits clearly perceivable depth-dependent color changes and remains visible through >2 cm of ex vivo chicken breast and bovine muscle tissue using less than 4 W of transmitted power from a handheld antenna. These miniaturized needle-injectable localization devices show promise for improving surgical guidance of nonpalpable breast tumors.
在乳腺癌保乳手术中，实现阴性切缘（定义为切除组织边缘未发现肿瘤）对于降低局部复发风险至关重要。为了识别无法触及的肿瘤（即触诊阴性的肿瘤），通常在术前使用导丝和无导丝定位设备进行定位。无导丝定位方法相对于有导丝技术具有显著的实际优势。在本研究中，我们引入了一种由发光二极管（LED）为基础的植入式设备和手持式系统组成的创新定位系统。该设备无需导丝、可通过注射针进行植入，利用多个无线供电的 LED 为保乳手术提供直接的视觉引导。两种不同的颜色，红色和蓝色，提供了明确的组织深度指示：蓝光在组织中被强烈吸收，在近距离（<1 厘米）内可见，而红光则可以穿透几厘米的组织。LED 与阻抗匹配电路和接收线圈集成在一起，封装在生物相容性环氧树脂中，可通过 12G 针进行注射。我们的研究结果表明，该植入物表现出明显的、与深度相关的颜色变化，使用手持天线传输小于 4W 的功率，在离体鸡胸和牛肌肉组织中可穿透超过 2cm 的距离仍清晰可见。这些微型针注射式定位设备有望改善触诊阴性乳腺肿瘤的手术指导。
