University of Texas at Austin.
University of Texas Health Science Center at San Antonio.
Theranostics. 2019 May 26;9(12):3555-3564. doi: 10.7150/thno.31811. eCollection 2019.
Higher precision surgical devices are needed for tumor resections near critical brain structures. The goal of this study is to demonstrate feasibility of a system capable of precise and bloodless tumor ablation. An image-guided laser surgical system is presented for excision of brain tumors in a murine xenograft model. The system combines optical coherence tomography (OCT) guidance with surgical lasers for high-precision tumor ablation (Er:YAG) and microcirculation coagulation (Thulium (Tm) fiber laser). A fluorescent human glioblastoma cell line was injected into mice and allowed to grow four weeks. Craniotomies were performed and tumors were imaged with confocal fluorescence microscopy. The mice were subsequently OCT imaged prior, during and after laser coagulation and/or ablation. The prior OCT images were used to compute three-dimensional tumor margin and angiography images, which guided the coagulation and ablation steps. Histology of the treated regions was then compared to post-treatment OCT images. Tumor sizing based on OCT margin detection matched histology to within experimental error. Although fluorescence microscopy imaging showed the tumors were collocated with OCT imaging, margin assessment using confocal microscopy failed to see the extent of the tumor beyond ~ 250 µm in depth, as verified by OCT and histology. The two-laser approach to surgery utilizing Tm wavelength for coagulation and Er:YAG for ablation yielded bloodless resection of tumor regions with minimal residual damage as seen in histology. Precise and bloodless tumor resection under OCT image guidance is demonstrated in the murine xenograft brain cancer model. Tumor margins and vasculature are accurately made visible without need for exogenous contrast agents.
需要更高精度的手术器械来进行靠近关键脑结构的肿瘤切除。本研究的目的是展示一种能够精确进行无血肿瘤消融的系统的可行性。提出了一种用于在鼠异种移植模型中切除脑肿瘤的图像引导激光手术系统。该系统将光学相干断层扫描（OCT）引导与手术激光结合，用于高精度肿瘤消融（Er：YAG）和微循环凝固（Tm 光纤激光）。将荧光人类胶质母细胞瘤细胞系注射到小鼠体内并使其生长四周。进行开颅术，并使用共聚焦荧光显微镜对肿瘤进行成像。随后对小鼠进行 OCT 成像，在激光凝固和/或消融之前、期间和之后进行。之前的 OCT 图像用于计算三维肿瘤边缘和血管造影图像，这些图像指导了凝固和消融步骤。然后将处理区域的组织学与治疗后的 OCT 图像进行比较。基于 OCT 边缘检测的肿瘤大小与组织学匹配，误差在实验范围内。尽管荧光显微镜成像显示肿瘤与 OCT 成像共定位，但共聚焦显微镜的边缘评估未能看到肿瘤在深度超过约 250 µm 的范围，这通过 OCT 和组织学得到了验证。利用 Tm 波长进行凝固和 Er：YAG 进行消融的双激光手术方法实现了肿瘤区域的无血切除，组织学上可见最小的残留损伤。在鼠异种移植脑癌模型中证明了在 OCT 图像引导下进行精确、无血的肿瘤切除。肿瘤边缘和脉管系统无需外源性对比剂即可准确显现。
