Neurosurgical Flexible Probe Microscopy With Enhanced Architectural and Cytological Detail

Background Microscopic delineation and clearance of tumor cells at neurosurgical excision margins potentially reduce tumor recurrence and increase patient survival. Probe-based in vivo fluorescence microscopy technologies are promising for neurosurgical in vivo microscopy. Objective We sought to demonstrate a flexible fiberoptic epifluorescence microscope capable of enhanced architectural and cytological imaging for in vivo microscopy during neurosurgical procedures. Methods Eighteen specimens were procured from neurosurgical procedures. These specimens were stained with acridine orange and imaged with a 3-dimensional (3D)-printed epifluorescent microscope that incorporates a flexible fiberoptic probe. Still images and video sequence frames were processed using frame alignment, signal projection, and pseudo-coloring, resulting in resolution enhancement and an increased field of view. Results Images produced displayed good nuclear contrast and architectural detail. Grade 1 meningiomas demonstrated 3D chords and whorls. Low-grade meningothelial nuclei showed streaming and displayed regularity in size, shape, and distribution. Oligodendrogliomas showed regular round nuclei and a variably staining background. Glioblastomas showed high degrees of nuclear pleomorphism and disarray. Mitoses, vascular proliferation, and necrosis were evident. Conclusions We demonstrate the utility of a 3D-printed, flexible probe microscope for high-resolution microscopic imaging with increased architectural detail. Enhanced in vivo imaging using this device may improve our ability to detect and decrease microscopic tumor burden at excision margins during neurosurgical procedures.