Intraoperative fluorescence control with chlorin E6 in resection of glial brain tumors

Abstract

To evaluate an effectiveness and feasibility of fluorescence navigation with chlorin E6 in surgery of brain gliomas. The study included 30 patients with glial brain tumors grade II-IV. All patients were operated at the Polenov Russian Neurosurgical Institute. We used surgical microscope (Leica OHS-1), D-Light AF System (Karl Storz, Germany), original fluorescence module (St. Petersburg LOMO, developed by G.V. Papayan) and special software RSS Cam - Endo 1.4.313 for visual analysis of fluorescence. Histological examination included hematoxylin-eosin staining of specimens and immunohistochemical studies. Fluorescence was weak in all patients with Grade II gliomas and strong in almost all patients with Grade III-IV gliomas. Sensitivity of fluorescence diagnosis with chlorin E6 was 72.2% for Grade II gliomas, 83.8% for Grade III gliomas and 87.7% for Grade IV. Specificity of this method was 60% for Grade II gliomas, 66.7% for Grade III gliomas and 85.2% for Grade IV. Certain method of fluorescence imaging ensured resection of glial brain tumors using chlorin E6. Intensity of tumor fluorescence correlated with glioma malignancy grade. These results indicate that chlorin E6 is an effective photosensitizer for intraoperative fluorescence diagnosis in surgery for glioma.