Introduction. Craniotomy in conscious patients is a possible tool for optimizing of tumor resection degree (Extent of Resection) while maintaining the quality of life. Traditionally, the main focus during these operations is on the cortical speech areas. At the same time, there is a shortage of studies on mapping of long associative tracts during the removal of gliomas of dominant speech hemisphere.Aim. To analyze the data of intraoperative mapping and the postoperative state of speech function in patients with temporal lobe gliomas of left hemisphere (including those involving arcuate bundle) operated by the use of method of craniotomy in consciousness.Materials and methods. Gliomas of temporal lobe of left hemisphere were removed in 27 patients aged 14 to 67 years (median age 43 years). In 10 patients, the tumor was localized in middle parts of temporal lobe (at the level of middle and upper temporal gyri), in 9 patients – in posterior parts of temporal lobe and exited into the supramarginal zone, in 8 it spread partially from temporal lobe to insular area. Gliomas of high degree of malignancy were detected in 21 patients, 6 had tumors of low degree of malignancy. Surgical intervention was performed with intraoperative “awakening”. All patients underwent cortical electrophysiological stimulation in order to control localization of cortical speech zones, subcortical stimulation was performed in 21 cases to identify terminals of arcuate bundle. Speech disorders before and after surgery (on day 4–6) were evaluated by neuropsychologist using the method proposed by A. R. Luria, an automated test with the naming of pictures was additionally used intraoperatively. The average current strength of direct electrical stimulation was 3 (1.9–6.5) mA. In 12 cases, magnetic resonance (MR) tractography with construction of arcuate tract was performed before and after the surgery.Results. Cortical temporal speech zones during intraoperative electrical stimulation were detected in 20 (74 %) of 27 patients. In 10 patients, the arcuate tract was mapped in form of appearance of mixed speech disorders in the depth of surgical wound. In 23 (85.2 %) of 27 patients in early postoperative period, an increase in speech disorders was noted of which 13 people had disorders of temporal type only and 10 people (surgery on deep posterior parts of temporal lobe) had a combination of temporal and frontal types of speech disorders (conduction aphasia). Postoperative MR‑tractography (performed in 12 patients) revealed direct intraoperative tract lesion in 5 cases and ischemia of the tract area passage in 2 cases. These 7 patients had combined speech disorders after surgery. Gross sensory aphasia after surgery was manifested in 4 patients, in 2 of them ischemia was revealed according to postoperative magnetic resonance imaging, and 2 more had hemorrhagic impregnation in the removed tumor bed.Conclusion. When removing tumors of temporal lobe in “awakening” conditions it is necessary to map speech zones not only in the cortical, but also in the subcortical area with terminals of arcuate bundle. Mapping of speech zones in these different localizations makes it possible to identify fundamentally different speech disorders.

Возможности магнитно-резонансной томографии в оценке гидроцефалии

Introduction. Metabolic navigation with 5‑ALA is one of methods for intraoperative imaging in neuro‑oncology.Aim. To perform a comparative analysis of sensitivity of metabolic navigation with 5‑ALA during surgery of primary and secondary brain tumors of various histological nature and degree of malignancy.Materials and methods. During the period from 2013 to 2020, our group have performed surgery to 403 patients using metabolic navigation: microsurgical resections were performed in 384 people with brain tumors, 220 of them were with glial tumors, 101 were with intracranial meningiomas, 63 were with metastatic brain damage. Among patients with metastases, 39 patients had a solitary injury, 16 had a multi‑focal injury, so 72 cases of metastatic nodes were considered in this group. Stereotactic biopsies with 5‑ALA‑assistance were performed in 19 people. Metabolic navigation was performed with the drug 5‑ALA, which was taken orally at a dose of 20 mg/kg 2 hours before surgery. Intraoperative fluorescence was evaluated using microscope with a fluorescent module.Results. Metabolic navigation using microscope has a high sensitivity when employed during microsurgery (including repeated implementation of surgery) in cases of anaplastic gliomas (65 % in total, 58 % with bright glow), glioblastomas (94 % in total, 53 % with bright glow), intracranial meningiomas (94 % in total, 64 % – with bright glow). The use of 5‑ALA has significant limitations in sensitivity in cases of diffuse gliomas (46 % – in total, 27 % – with bright glow) and brain metastases (in total 87 % – for the solid part, 52 % – for the bed, with bright glow – 51 %). In diffuse gliomas, the glow areas had significantly higher proliferative index and cell nuclei density than the fluoronegative zones. Among the most important factors affecting the glow of gliomas it can be noted: the status of the IDH1 mutation, the volume of the contrasting part of the glioma according to MRI data, the methionine accumulation index according to positron emission tomography, the tumor blood flow indicators according to the arterial spin marking method – ASL perfusion.Conclusions. Implementation of 5‑ALA navigation with the use of microscope provides high sensitivity in cases of glioblastomas, anaplastic gliomas (especially for detecting of non‑contrasting part of tumor that is not visually altered in the white light of operating microscope) and brain meningiomas. The method is less effective in low‑grade gliomas and intracranial metastases.

The aim of this study was to evaluate average ¹¹ C-methionine uptake for grade II (anaplastic) gliomas in a large cohort, as well as relations between MRI and PET characteristics and their unfluence on overall and progression-free survival. Materials and methods . The study was based upon 78 patients with supratentorial tumors, among them 48 with anaplastic astrocytoma (AA) and 30 with anaplastic oligodendroglioma (AO). ALL patients underwent PET-CT with ¹¹ C-methionine and MRI study (Т1, Т2, Т2-FLAIR, DWI и 3D Т1+Gd regimes). Tumor removal was performed in 71 cases, stereotactic biopsy in 8 patients. Tumor specimen were assessed by neuropatomorphologists and IDH1-status and 1p/19q co-deletion were evaluated. Study results . AA IDH ⁻ tumors demonstrated statistically significant bigger metabolic volume and radiotracer uptake comparing with AA IDH ⁺ . Moreover, AA IDH − characterized by higher fractional MET uptake. The smallest tumors (by MRI) were AOs, meanwhile their fractional contrast enhancement was higher than for AAs. AOs were also known as tumors with minimal difference between MRI and PET-CT volume. MET uptake decreased in a row АА IDH ⁻ – АОД – AA IDH ⁺ , but the difference has not reached statistical significance. For wild-type AAs metabolic volume correlated with OS and PFS, meanwhile for IDH-mutant AAs tumor volume (measured by MRI) correlated only with PFS. Conclusion . Present study based on the largest cohort of patients with anaplastic gliomas who underwent both MRI and PET with ¹¹ C-methionine. It turned out, that unlike grade II oligodendogliomas, AOs do not always demonstrate higher than their astrocytic counterparts MET uptake levels.

The aim of the study was to assess T2/T2-FLAIR mismatch phenomenon as a predictor of particular genetic profile in the anaplastic astrocytoma group, including those tumors demonstrating contrast enhancement on MRI. Materials and methods . It is a retrospective study. All MR images were anonymized. MRI analysis. We studied 242 MRIs of patients with anaplastic astrocytomas (AA) and anaplastic oligodendrogliomas (AO) who were surgically treated at Burdenko Neurosurgery Center from 01.01.2017 to 31.12.2019. Among 242 patients we identified 23 (9.5%) whose MRI fulfilled the criteria for T2/FLAIR mismatch sign. The images were studied by 3 experienced neuroradiologist and patients were allocated to the T2/FLAIR mismatch group only upon consensus. Readers evaluated T2WI and FLAIR sequences of each MRI examination. They determined thr following characteristics of the tumours, using a binary scoring system for each: 1) presence or absence of homogeneous signal intensity on T2WI; 2) presence or absence of complete/near-complete hyperintence signal on T2WI, and relatively hypointence on FLAIR except for a hyperintense peripheral rim; 3) margins of lesion sharp or indistinct; 4) presence or absence of peritumoral edema. Discordant results were resolved by consensus with more experienced neuroradiologist. Histological examination and molecular markers . Histological examination was carried out by 2 qua lified pathologists after staining the preparations with hematoxylin and eosin and calculating the index of proliferative activity. The final diagnosis was established on the basis of a combination of morphological and molecular genetic studies. The material for the study was 242 biopsies from patients operated on at Burdenko Neurosurgery Center with anaplastic astrocytomas and anaplastic oligodendrogliomas WHO Grade III, fixed in 10% neutral formalin and embedded in Histomax (Leica) paraffin. Among 23 patients with T2 / FLAIR mismatch in 4 archival cases was performed an immunohistochemical study with Anti-IDH1 R132H (clone H09) (dianova) antibodies to establish the mutational status of the IDH-1 gene; in 19 remaining cases the IDH1 R132H mutation was studied by real-time PCR using self-selected primers and probes. One of the samples showed the wild type IDH1 R132H and it was further investigated by Sanger sequencing to determine the mutational status of the IDH1 and IDH2 genes using direct primers. Determination of 1p / 19q co-deletion was performed by in situ fluorescence hybridization using a ZytoLight Glioma 1p / 19q Probe Set (ZytoVision). Study results . T2/T2-FLAIR mismatch sign was found in 23 patients with AA, in 8 cases tumors demonstrated contrast enhancement, including 3 of them with substantial enhancement. The mean age in the T2/T2-FLAIR mismatch group was lower than in the main group (34 vs. 42.7 years), as well as percentage of patients with contrastenhancing tumors (36.4% vs. 55.8%). The proportion of tumors with substantial contrast enhancement was similar in both groups (37.5% vs. 46.7%). Discussion S.H. Patel et al. in their pioneer paper demonstrated 12% frequency of T2/FLAIR mismatch sign in the experimental group (125 patients) and 17% in validation group (60 patients). M.P.G. Broen et al. present with a higher rate of the sign – 25%. S. Deguchi et al. have demonstrated even higher frequency of T2/FLAIR mismatch among IDHmutant grade II astrocytomas -45%. Our results revealed 9.5% rate of this sign. The first article declaring less than 100% specificity of T2/FLAIR mismatch sign, after great success and acknowledgement of this predictive diagnostic method, was published by T.A. Juratli et al. 2019: the sign was observed in 73% of patients (versus 12% in Patel’s group). Herewith, 29% of patients with T2/FLAIR mismatch sign demonstrated both IDH-1 mutation and 1p/19q co-deletion. The reason for this phenomenon were less strict inclusion criteria in Juratli’s study. Moreover, authors did not specify the number of patients with contrast-enhancing tumors, although according to R. Jain et al., all these tumors must be excluded from the study. It is noteworthy, that even with these non-strict inclusion criteria, T2/FLAIR mismatch sign has demonstrated 100% predictive value for IDH-1 mutation in Jurartli’s study (none of the patients presented with IDH-wild type tumour). In the meta-analysis performed by Goyal et al. 2019, based on several T2/FLAIR mismatch studies with 746 patients, authors demonstrated high specificity (98.5%) and low sensitivity (33.7%) of this sign for detecting IDH-1+ and 1p/19q- cooperation. The main conclusion of this paper is that T2/FLAIR mismatch sign has high specificity and low sensitivity for detecting IDH-1 mutation, but not 1p/19q co-deletion, although there might be exceptions from this rule. Recent studies devoted to the T2/FLAIR mismatch sign included mostly grade II gliomas and a small amount of AA and AO, emphasizing that those tumors did not demonstrate contrast enhancement M.P.G. Broen, S.H. Patel. Moreover, this characteristic is referred as a necessary qualification for T2/FLAIR mismatch sign, since contrastenhancing parts of the tumor may overlap area of interest and confound MRI signal in other sequences. Results of our study convincingly demonstrate possibility of T2/FLAIR mismatch sign in grade III gliomas with contrast enhancement. We observed this phenomenon in 8 cases out of 22 (36.4%). Moreover, among those8 patients, 3 presented with intensive contrast enhancement. Comparing main group with control one, we revealed, that mean age in the group with T2/FLAIR mismatch sign was lower (34 vs. 42.7). and among 8 patients with contrast enhancement only 1 was older than 40 years. Tumors from the main group demonstrated contrast enhancement significantly on a more frequent basis (55.8% vs. 36.4%), meanwhile rate of intensive contrast enhancement was similar (46.7% vs. 37.5%). Thus, we demonstrated correlation between tumour grade and contrast enhancement and T2/FLAIR mismatch sign. Earlier studies made attempts to predict tumor mutational status upon MRI: for instance, frontal lobe tumours, not spreading to the midline structures more often demonstrate IDH mutation Z.L. Sun, A. Lai. Moreover, it is wellknown fact, that IDH+ gliomas present with more distinct borders, more homogeneous MR-signal and less frequently demonstrate contrast enhancement A. Lai, G. Reyes-Botero. However, all these characteristics are very subjective and only advisory. More explicit results can be revealed by using MR-perfusion P. Kickingereder, MR-spectroscopy (2-hydroxyglutarat) M.I. de la Fuente and PET B. Suchorska 2017. However, abovementioned methods are not so widespread, unlike MRI, which is capable to predict genetic profile (IDH and 1p/19q status) with almost 100% accuracy. Unconditioned weakness of this method is qualitative, not quantitative his nature, sometimes demanding discussion and still not unambiguous. Probably, future achievements in neuroradiology will allow to perform quantitative analysis of MR-signal and formalize T2/FLAIR mismatch sign. It is difficult to overestimate T2/FLAIR mismatch sign for diagnosis, surgery planning and overall treatment strategy. These aspects were disputed for grade II gliomas Sofietti, A.S. Jakola, M.M.J. Wijnenga. Anaplastic tumours possess worse prognosis and this additional information might be of extreme use. T. Kawaguchi et al. evaluated correlation between radical resection and prognosis of treatment for AA tumours with and without IDHmutation: it turned out, that for IDH-negative tumors radical surgery did not significantly affect overall survival (although these groups demonstrated different OS). On the contrary, radical resection significantly affected OS for IDH+ gliomas. Our study has demonstrated capability T2/FLAIR mismatch sign detection for anaplastic gliomas regardless of tumour contrast enhancement. It is still unclear why not all IDH-positive 1p/19q-negative gliomas demonstrate T2/FLAIR mismatch sign. These “exceptions” were documented earlier by S.H. Patel, M.P.G. Broen for grade II gliomas and in our study for grade III gliomas: only 23 out of 26 patients with above-mentioned molecular profile presented with T2/FLAIR mismatch sign. S.H. Patel et al. speculate about activation of pathways by mTOR protein, which is involved in IDH-positive gliomas malignant change H. Wakimoto, but lack of data precludes authors from statistically significant conclusions. Conclusion . Study results confirm the hypothesis of relevance of T2/T2-FLAIR mismatch sign for anaplastic atrocytomas with contrast enhancement on MRI as highly specific biomarker for tumor genetic profile. In some cases information provided by MRI in this group of patients may improve preoperative diagnostic and affect treatment strategy.