Аннотация:Objective. To evaluate the effectiveness and feasibility of using fluorescence navigation with chlorin Е6 in the surgery of gliomas of various degrees of malignancy. Materials and methods. The study included 28 patients with glial tumors of varying degrees of malignancy according to Grade (II-IV). All patients were operated on the basis of the Russian Neurosurgical Institute name after prof. A.L. Polenov. For visual fluorescence studies, equipment was used in the form of a Leica OHS surgical microscope, a D-Light AF System installation by Karl Storz (Germany), an in-house fluorescence module (St. Petersburg LOMO, developed by G.V. Papayan) and special software RSS Cam - Endo 1.4.313. For histological study of biopsy samples, hematoxylin-eosin staining and immunohistochemical studies were adopted. Results. In 28 patients with fluorescence navigation, the contrast was assessed on preoperative MRI images in T1 mode. Contrasting was assessed on a 4-point scale (0 - no contrasting (2 (7.2%) patients), 1 - focal contrasting (9 (32.1%) patients), 2 - uniform contrasting (6 (21.4%) patients), 3 - annular accumulation of contrast with hypodense content in the center of the tumor (11 (39.3%) patients)). A comparative analysis of visible fluorescence with the data of preoperative MRI with contrast (T1 mode) showed a direct correlation (p> 0.05) from the accumulation of contrast on MRI and the degree of glioma anaplasia. The zone of tumor necrosis corresponded to the absence of contrast accumulation on MRI and the absence of chlorine e6 fluorescence. The zone of the compact part of the tumor corresponded to the maximum level of contrast accumulation on MRI and the maximum fluorescence of chlorine e6 (+++). The zone of cellular infiltration corresponded to a non-intense, uneven accumulation of contrast on MRI and less intense (++ and +) fluorescence. Benign gliomas were characterized by a more uniform and non-intensive accumulation of contrast on MRI, an MRI picture closer to the normal structure of the gyri, and homogeneous moderate (++) or weak (+) fluorescence.Comparative analysis of PET with methionine and chlorin e6 conditioned fluorescence in 15 patients with glioblastoma, 10 patients with anaplastic astrocytoma, and 2 patient with fibrillar-protoplasmic astrocytoma showed a direct correlation between the accumulation index, fluorescence intensity of chlorine e6 (p<0,05). A higher accumulation index (1.7-3.9) and brighter fluorescence of chlorine e6 (+++) were noted in glioblastoma (Grade IV). A low accumulation index (0.7) and very weak fluorescence (+) were noted in Grade II tumors. It was confirmed at a histological level that the fluorescence intensity was weak in all patients with Grade II gliomas and strong in almost all patients with Grade III-IV gliomas. The sensitivity of the method of fluorescence diagnostics with chlorin Е6 for Grade II gliomas was 72.2%, for Grade III gliomas - 83.8%, for Grade IV - 87.7%. The specificity of the method was 60% for Grade II gliomas, 66.7% for Grade III gliomas, and 85.2% for Grade IV. Conclusion. The use of a certain system of fluorescence imaging allowed resection of glial brain tumors using chlorin Е6, and the intensity of tumor fluorescence correlated with the degree of glioma malignancy. These results indicate that chlorin Е6 is an effective photosensitizer for intraoperative fluorescence diagnostics in glioma surgery.
