Development of fluorescence guided navigation system using a near infra-red fluorescent agent

我们研制了一种近红外荧光可视化系统，并将其应用于脑肿瘤动物模型的肿瘤检测。本实验采用吲哚花青素绿（ICG）作为荧光增强材料。780 nm激光器激发光照射手术场。利用红外CCD相机结合800 nm低通滤波器对近红外荧光进行可视化。我们证实ICG积聚于颅内肿瘤，其荧光透过薄颅骨、大脑皮层和硬脑膜清晰可见。结论：近红外荧光肿瘤显像系统对深部隐蔽性肿瘤的检测具有优势。为了改进普通的5-氨基乙酰丙酸（5-ALA）肿瘤显像系统，我们研制了激光荧光手术内镜系统，并将其应用于脑室内肿瘤的活检。脑室内肿瘤常被室管膜上皮所覆盖，其确切存在变得模糊。该激光荧光手术内镜系统使我们能够准确地发现肿瘤的延伸，保证可靠的肿瘤活检。另一个改进点是将5-ALA荧光引导肿瘤切除应用于恶性胶质瘤以外的另一种脑肿瘤。作为最常见的中枢神经系统良性肿瘤，我们发现超过80%的毛发瘤显示出来自5-ALA的强荧光。在恶性脑膜瘤并扩展到周围结构，如脑、血管和颅骨的情况下，有肿瘤残留和局部复发的风险。5-ALA荧光引导手术在此类病例中具有良好的临床应用价值，可防止肿瘤残留和复发。

We developed a near infra-red fluoscopic visualizing system and applied it to detect the tumor of the animal model of brain tumor. In this experiment, we employed the indocyanin green (ICG) for the fluorescent enhanced material. The excitation light from 780 nm laser was irradiated the operative field. The near infra-red fluorescence were visualized using infra-red CCD camera combined with low pass filter of 800 nm. We confirmed that ICG was accumulate to the intracranial tumor and its fluorescence was clearly visualized as a bright area through the thin skull, cerebral cortex, and dura matter. In conclusion, near infra-red fluorescence tumor visualizing system has advantageous to detect the deep seated cryptic tumor.In order to improve the ordinary tumor visualizing system using 5-aminolevulinic acid (5-ALA), we developed the Laser fluorescent operative endoscopic system, and applied it for biopsy of the intra-ventricular tumor. Intra-ventricular tumors are often covered by the ependymal epithelium and the exact existence become vague. This laser fluorescent operative endoscopic system enables us to find us the exact tumor extend and ensure the reliable tumor biopsy.Another improved point was to apply the fluorescence guided tumor removal using 5-ALA to another brain tumor other than malignant glioma. As for the maningiomas, which are the most popular benign neoplasm at the central nervous system, we fond that the more than 80 % of maningiomas showed the strong fluorescence derived from 5-ALA. In the cases of malignant menintiomas and extended to surrounding structures, such as brain, vessels, and skull, has a risk of tumor residue and local recurrence. The 5-ALA fluorescent guided surgery is a good clinical application in such cases to prevent from tumor residue and recurrence.