Waanders S, Visscher M, Wildeboer R R, Oderkerk T O B, Krooshoop H J G, Ten Haken B
MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, The Netherlands.
Phys Med Biol. 2016 Nov 21;61(22):8120-8134. doi: 10.1088/0031-9155/61/22/8120. Epub 2016 Oct 26.
Sentinel lymph node biopsy has become a staple tool in the diagnosis of breast cancer. By replacing the morbidity-plagued axillary node clearance with removing only those nodes most likely to contain metastases, it has greatly improved the quality of life of many breast cancer patients. However, due to the use of ionizing radiation emitted by the technetium-based tracer material, the current sentinel lymph node biopsy has serious drawbacks. Most urgently, the reliance on radioisotopes limits the application of this procedure to small parts of the developed world, and it imposes restrictions on patient planning and hospital logistics. Magnetic alternatives have been tested in recent years, but all have their own drawbacks, mostly related to interference from metallic instruments and electromagnetic noise coming from the human body. In this paper, we demonstrate an alternative approach that utilizes the unique nonlinear magnetic properties of superparamagnetic iron oxide nanoparticles to eliminate the drawbacks of both the traditional gamma-radiation centered approach and the novel magnetic techniques pioneered by others. Contrary to many other nonlinear magnetic approaches however, field amplitudes are limited to 5 mT, which enables handheld operation without additional cooling. We show that excellent mass sensitivity can be obtained without the need for external re-balancing of the probe to negate any influences from the human body. Additionally, we show how this approach can be used to suppress artefacts resulting from the presence of metallic instruments, which are a significant dealbreaker when using conventional magnetometry-based approaches.
前哨淋巴结活检已成为乳腺癌诊断的主要工具。通过仅切除最有可能含有转移灶的淋巴结来取代饱受病痛折磨的腋窝淋巴结清扫术，它极大地改善了许多乳腺癌患者的生活质量。然而，由于使用基于锝的示踪剂材料所发射的电离辐射，当前的前哨淋巴结活检存在严重缺陷。最紧迫的是，对放射性同位素的依赖将该程序的应用限制在发达国家的小部分地区，并且对患者规划和医院后勤工作施加了限制。近年来已经对磁性替代方法进行了测试，但所有方法都有其自身的缺点，大多与金属器械的干扰以及来自人体的电磁噪声有关。在本文中我们展示了一种替代方法，该方法利用超顺磁性氧化铁纳米颗粒独特的非线性磁特性来消除传统的以伽马辐射为中心的方法以及其他人开创的新型磁性技术的缺点。然而，与许多其他非线性磁性方法不同的是，场振幅限制在5毫特斯拉，这使得无需额外冷却即可进行手持操作。我们表明，无需对探头进行外部重新平衡以消除来自人体的任何影响，就能获得出色的质量灵敏度。此外，我们展示了这种方法如何用于抑制由金属器械的存在所导致的伪影，而在使用传统的基于磁力测量的方法时，这些伪影是一个重大的障碍。
