Background: This study aimed to analyze the relationship between molecular pathologic expression of GFAP and Ki-67 and fluorescence levels, and to provide molecular pathological basis for the removal of malignant gliomas (MG) by Fluorescein Sodium (FLS) navigation under the YELLOW 560 nm surgical microscope filter.
Methods: A retrospective analysis of clinical data of 18 MG cases confirmed by the postoperative pathology was performed. All cases were resected by FLS guiding under the YELLOW 560 nm filter. Hematoxylin-eosin (HE) staining, molecular pathology markers GFAP, and Ki-67 immunohistochemical staining of the specimens were performed. The relationship between fluorescence staining levels and GFAP positive rate, Ki-67 proliferation index, and WHO grades was studied.
Results: There were 69 pathological specimens with fluorescence levels of "bright" fluorescence (n = 32), "low" fluorescence (n = 18), and "no" fluorescence (n = 19). Immunohistochemical staining showed GFAP-positive expression in both tumor cells and normal glial cells. The staining levels of the specimens in the fluorescence regions were higher than that in the non-fluorescence regions. GFAP expression was positive in 61 specimens and negative in 8 specimens. Comparison of Ki-67 proliferation index using chi-square test showed different fluorescence levels had different Ki-67 proliferation indexes (χ2 = 14.678, p = 0.005). With high proliferation index of specimens, fluorescence level was brighter. WHO grade had no correlation with fluorescence levels (χ2 = 3.531, p = 0.171).
Conclusion: FLS-guided resection of MG is safe and effective. In the boundary area of MG, fluorescence levels and Ki-67 proliferation index showed correlation. FLS-guided resection achieved the function of "reducing tumor cell," thus reducing the proliferation index in the lesion area.
Keywords: Fluorescein sodium; GFAP; Ki-67; Malignant glioma; YELLOW 560 nm.