Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
Ann Surg Oncol. 2013 Oct;20(11):3685-93. doi: 10.1245/s10434-012-2434-z. Epub 2012 Jun 12.
Numerous techniques have been developed for localizing lymph nodes before surgical resection and for their histological assessment. Nondestructive high-resolution transcapsule optical imaging of lymph nodes offers the potential for in situ assessment of metastatic involvement, potentially during surgical procedures.
Three-dimensional optical coherence tomography (3-D OCT) was used for imaging and assessing resected popliteal lymph nodes from a preclinical rat metastatic tumor model over a 9-day time-course study after tumor induction. The spectral-domain OCT system utilized a center wavelength of 800 nm, provided axial and transverse resolutions of 3 and 12 μm, respectively, and performed imaging at 10,000 axial scans per second.
OCT is capable of providing high-resolution label-free images of intact lymph node microstructure based on intrinsic optical scattering properties with penetration depths of ~1-2 mm. The results demonstrate that OCT is capable of differentiating normal, reactive, and metastatic lymph nodes based on microstructural changes. The optical scattering and structural changes revealed by OCT from day 3 to day 9 after the injection of tumor cells into the lymphatic system correlate with inflammatory and immunological changes observed in the capsule, precortical regions, follicles, and germination centers found during histopathology.
We report for the first time a longitudinal study of 3-D transcapsule OCT imaging of intact lymph nodes demonstrating microstructural changes during metastatic infiltration. These results demonstrate the potential of OCT as a technique for intraoperative, real-time in situ 3-D optical biopsy of lymph nodes for the intraoperative staging of cancer.
为了在手术切除前定位淋巴结并进行组织学评估，已经开发出许多技术。无损高分辨率经皮光学成像技术为淋巴结的原位评估提供了潜力，这种评估有可能在手术过程中进行。
使用三维光学相干断层扫描（3-D OCT）对诱导肿瘤后 9 天的临床前大鼠转移性肿瘤模型切除的腘淋巴结进行成像和评估。该光谱域 OCT 系统利用 800nm 的中心波长，提供 3μm 的轴向和 12μm 的横向分辨率，每秒进行 10000 次轴向扫描。
OCT 能够提供基于固有光散射特性的完整淋巴结微观结构的高分辨率无标记图像，其穿透深度约为 1-2mm。结果表明，OCT 能够根据微观结构的变化区分正常、反应性和转移性淋巴结。从向淋巴结系统注射肿瘤细胞后的第 3 天到第 9 天，OCT 显示的光散射和结构变化与组织病理学中观察到的胶囊、皮质前区、滤泡和生发中心的炎症和免疫变化相关。
我们首次报告了一项完整淋巴结经皮 3-D OCT 成像的纵向研究，该研究显示了转移性浸润过程中的微观结构变化。这些结果表明，OCT 有潜力成为一种用于术中实时原位 3-D 光学活检淋巴结的技术，以进行癌症的术中分期。
