ИСТИНА

Method: A total of 33 patients with glial brain tumors of supratentorial localization (Grade II - 8, Grade III - 11, Grade IV - 15). All patients underwent intraoperative fluorescence diagnostics with chlorine E6 of the 2nd generation (1 mg / kg), and the contrast was assessed in preoperative MRI images in T1 mode and PET with methionine. The contrast assessment on MRI was carried out on a 4-point scale (0 - no contrast (3 (9.1%) patients), 1 - focal contrast (10 (30.3%) patients), 2 - uniform contrast (8 (24.2 %) of patients), 3 - annular accumulation of contrast with hypodensity in the center of the tumor (12 (36.4%) patients)). Result: A comparative analysis of visible fluorescence with preoperative MRI with contrast (T1 mode) yielded a direct correlation (p> 0.05) from contrast accumulation on MRI and the degree of glioma anaplasia. The higher the degree of anaplasia, the more pronounced the contrast according to MRI and the brighter the visible intraoperative tumor fluorescence. The accumulative ability of contrast on MRI with gliomas of a low degree of anaplasia was most characteristic of oligodendrogliomas, gliomas with the presence of a cystic component. Thus, the sensitivity of the method for Grade II gliomas was 68.7%, specificity - 60.5%, and for Grade III – IV gliomas - 85.3% and 77.1%, respectively. A comparative analysis of PET with methionine and chlorin e6-mediated fluorescence yielded a direct correlation between the accumulation index, fluorescence intensity, and the degree of tumor anaplasia (p <0.05). A higher accumulation index (1.7–3.9) and brighter fluorescence (+++) were noted in glioblastoma (Grade IV). A low accumulation index (0.9) and very weak fluorescence (+) were observed with Grade II tumors. Thus, with low-grade gliomas, the sensitivity of PET was 88%, and for chlorin-mediated navigation, 79%. The boundaries of the tumor using various techniques ranged up to 7 mm. Discussion & Conclusion: The higher the degree of anaplasia, the more pronounced the contrast according to MRI and the brighter the visible intraoperative fluorescence of chlorin e6 in the tumor. A higher PET radiopharmaceutical accumulation index and brighter fluorescence were noted with Grade IV. A low accumulation index and very weak fluorescence were observed with Grade II tumors. Chlorin e6 and contrast on MRI are practically not visualized in the area of tumor necrosis, as well as a decrease in the activity of accumulation of the radiopharmaceutical according to PET + CT.