■5-氨基乙酰丙酸(5-ALA)荧光技术现已广泛应用于特定中枢神经系统(CNS)肿瘤的术中可视化。该技术的先前技术实施依赖于专门修改的手术显微镜来可视化肿瘤内荧光原卟啉(PpIX)。虽然这种方法显然允许可靠的术中肿瘤可视化,它需要专门修改的手术显微镜的可用性和他们的使用,即使在情况下,手术神经外科医生会喜欢使用手术放大镜。最近,引入了一种新颖的放大镜装置,该装置还能够可视化5-ALA荧光。
■因此,本研究的目的是比较常规荧光显微镜和新型放大镜装置之间检测到的PpIX浓度。
■我们使用不同PpIX浓度的荧光体模进行常规荧光显微镜和新型放大镜装置之间的比较。为此,我们创建荧光图像使用激发光源的传统荧光显微镜和放大镜装置与两种可用的背景照明模式(低和高)。随后,5名独立的神经外科医师确定了根据每种技术检测到的最低PpIX浓度.
■使用常规的荧光显微镜,PpIX最低检测浓度中位数为0.16μg/ml(范围:0.15~0.17μg/ml).通过放大镜装置,对于高模式和低模式,PpIX的最小可检测浓度中位数为0.12μg/ml(范围:0.10至0.12μg/ml)和0.08μg/ml(范围:0.07至0.08μg/ml),分别。总之,与常规荧光显微镜相比,使用放大镜装置的最低可检测PpIX浓度显著较低(p=0.007).
■我们的数据表明,新型放大镜装置能够以高灵敏度可视化5-ALA荧光,因此将来可能成为可视化特定CNS肿瘤的强大工具。
The 5-aminolevulinic acid (5-ALA) fluorescence technique is now widely applied for intraoperative visualization of specific central nervous system (CNS) tumors. Previous technical implementations of this technique have relied on specifically modified surgical microscopes to visualize intratumoral fluorescent protoporphyrin (PpIX). While this approach evidently allows for reliable intraoperative tumor visualization, it requires the availability of specifically modified surgical microscopes and their use even in cases where the operating neurosurgeon would prefer to use surgical loupes. Recently, a novel loupe device was introduced that is also capable of visualizing 5-ALA fluorescence.
The aim of this study was therefore to compare the detected PpIX concentrations between the conventional fluorescence microscope and the novel loupe device.
We used fluorescence phantoms of different PpIX concentrations for comparison between a conventional fluorescence microscope and the novel loupe device. For this purpose, we created fluorescence images using the excitation light sources of the conventional fluorescence microscope and the loupe device with both available background illumination modes (low and high). Subsequently, the minimal detectable PpIX concentrations according to each technique were determined by five independent neurosurgeons.
Using the conventional fluorescence microscope, the median minimal detectable PpIX concentration was 0.16 μg/ml (range: 0.15 to 0.17 μg/ml). By the loupe device, the median minimal detectable PpIX concentration was 0.12 μg/ml (range: 0.10 to 0.12 μg/ml) and 0.08 μg/ml (range: 0.07 to 0.08 μg/ml) for the high- and low-modes, respectively. Altogether, the minimal detectable PpIX concentrations were significantly lower using the loupe device compared to the conventional fluorescence microscope (p=0.007).
Our data indicate that the novel loupe device is able to visualize 5-ALA fluorescence with high sensitivity and thus might serve as a powerful tool for visualization of specific CNS tumors in the future.