Böhringer H J, Boller D, Leppert J, Knopp U, Lankenau E, Reusche E, Hüttmann G, Giese A
Department of Neurosurgery, University Hospital Schleswig-Holstein, Campus Luebeck, Luebeck, Germany.
Lasers Surg Med. 2006 Jul;38(6):588-97. doi: 10.1002/lsm.20353.
Detection of residual tumor during resection of glial brain tumors remains a challenge because of a low inherent contrast of adjacent edematous brain, the surrounding infiltration zone, and the solid tumor. Therefore, new technologies that may facilitate an intraoperative analysis of the tissue at the resection edge are of great interest to neurosurgeons.
For ex vivo imaging of gliomas in a mouse model and human biopsy specimens of brain tumors and nervous system tissue we have used a time-domain Sirius 713 Tomograph with a central wavelength of 1,310 nm and a coherence length of 15 microm equipped with a mono mode fiber and a modified optical coherence tomography (OCT) adapter containing a lens system for imaging at a working distance of 2.5 cm. A spectral-domain tomograph using 840 nm and 930 nm superluminescence diodes (SLD) with a central wavelength of 900 nm was used as a second imaging modelity.
Both time-domain and spectral-domain coherence tomography delineated normal brain, the infiltration zone and solid tumor in murine intracerebral gliomas. Histological evaluation of H&E sections parallel to the optical plain demonstrated that tumor areas of less than a millimeter could be detected and that not only solid tumor, but also brain invaded by a low-density single tumor cells produced an OCT signal different from normal brain. Spectral-domain OCT (SD-OCT) demonstrated a significantly more detailed microstructure of tumor and normal brain up to a tissue depth of 1.5-2.0 mm, whereas the interpretation of time-domain OCT (TD-OCT) was difficult at a tissue depth >1.0 mm. Because of rapid scanning times SD-OCT data could be acquired as 3D data maps, which allowed a multi-planar analysis of the tumor to brain interface. Similar to our findings in experimental gliomas, images of human nervous system tissue acquired using SD-OCT showed a characteristic signal of normal brain tissue and a detailed microstructure of tumor parenchyma.
Spectral-domain OCT of experimental gliomas and human brain tumor specimens differentiates solid tumor, diffusely invaded brain tissue, and adjacent normal brain based on microstructure and B-scan signal characteristics. In conjunction with the rapid image acquisition rates of SD-OCT, this technology carries the potential of a novel intraoperative imaging tool for the detection of residual tumor and guidance of neurosurgical tumor resections.
在切除脑胶质瘤过程中，由于相邻水肿脑组织、周围浸润区和实体瘤的固有对比度较低，检测残留肿瘤仍然是一项挑战。因此，可能有助于对切除边缘组织进行术中分析的新技术引起了神经外科医生的极大兴趣。
为了对小鼠模型中的胶质瘤以及脑肿瘤和神经系统组织的人类活检标本进行离体成像，我们使用了一台时域Sirius 713断层扫描仪，其中心波长为1310nm，相干长度为15微米，配备单模光纤和一个改良的光学相干断层扫描（OCT）适配器，该适配器包含一个透镜系统，用于在2.5cm的工作距离处成像。使用一台光谱域断层扫描仪作为第二种成像方式，该光谱域断层扫描仪使用中心波长为900nm的840nm和930nm超发光二极管（SLD）。
时域和光谱域相干断层扫描均描绘出了小鼠脑内胶质瘤中的正常脑组织、浸润区和实体瘤。与光学平面平行的苏木精-伊红（H&E）切片的组织学评估表明，可以检测到小于一毫米的肿瘤区域，并且不仅实体瘤，而且被低密度单个肿瘤细胞侵袭的脑也产生了与正常脑不同的OCT信号。光谱域OCT（SD-OCT）在组织深度达1.5 - 2.0mm时显示出肿瘤和正常脑更为详细的微观结构，而在组织深度>1.0mm时，时域OCT（TD-OCT）的解读较为困难。由于扫描时间短，SD-OCT数据可以采集为三维数据图，这使得能够对肿瘤与脑的界面进行多平面分析。与我们在实验性胶质瘤中的发现相似，使用SD-OCT获取的人类神经系统组织图像显示出正常脑组织的特征信号以及肿瘤实质的详细微观结构。
实验性胶质瘤和人类脑肿瘤标本的光谱域OCT基于微观结构和B扫描信号特征区分实体瘤、弥漫性侵袭的脑组织和相邻的正常脑。结合SD-OCT快速的图像采集速率，这项技术具有成为一种用于检测残留肿瘤和指导神经外科肿瘤切除的新型术中成像工具的潜力。
