Label-free detection of brain invasion in meningiomas by multiphoton microscopy

Brain invasion in meningiomas relates to the poor prognosis. Therefore, accurate detection and treatment of brain invasion are of particular importance. In this study, multiphoton microscopy (MPM) was introduced for label-free detection of brain invasion in meningiomas by the combination of the two-photon excited fluorescence imaging, second-harmonic generation imaging and spectral imaging. Results show that MPM has the ability to morphologically and spectrally identify brain invasion in meningiomas. What is more, the intensity ratios of the cerebral cortex over meningiomas at 475 nm, 511nm and 540nm were extracted as quantitative indicators for differentiating meningioma from surrounding normal cerebral cortex tissue. Together with custom-developed image processing algorithms, MPM could further identify the tumor boundary. With miniaturization and optimization of probes and optical fiber for in vivo imaging, combined with a laser ablation system, MPM would be used in an operating room for both the diagnosis and treatment of brain invasion in meningiomas.