Fully Automated MR Based Virtual Biopsy of Cerebral Gliomas

Objective: The aim of this study was to investigate the diagnostic accuracy of a radiomics analysis based on a fully automated segmentation and a simplified and robust MR imaging protocol to provide a comprehensive analysis of the genetic profile and grading of cerebral gliomas for everyday clinical use. Methods: MRI examinations of 217 therapy-naïve patients with cerebral gliomas, each comprising a non-contrast T1-weighted, FLAIR and contrast-enhanced T1-weighted sequence, were included in the study. In addition, clinical and laboratory parameters were incorporated into the analysis. The BraTS 2019 pretrained DeepMedic network was used for automated segmentation. The segmentations generated by DeepMedic were evaluated with 200 manual segmentations with a DICE score of 0.8082 ± 0.1321. Subsequently, the radiomics signatures were utilized to predict the genetic profile of ATRX, IDH1/2, MGMT and 1p19q co-deletion, as well as differentiating low-grade glioma from high-grade glioma. Results: The network provided an AUC (validation/test) for the differentiation between low-grade gliomas vs. high-grade gliomas of 0.981 ± 0.015/0.885 ± 0.02. The best results were achieved for the prediction of the ATRX expression loss with AUCs of 0.979 ± 0.028/0.923 ± 0.045, followed by 0.929 ± 0.042/0.861 ± 0.023 for the prediction of IDH1/2. The prediction of 1p19q and MGMT achieved moderate results, with AUCs of 0.999 ± 0.005/0.711 ± 0.128 for 1p19q and 0.854 ± 0.046/0.742 ± 0.050 for MGMT. Conclusion: This fully automated approach utilizing simplified MR protocols to predict the genetic profile and grading of cerebral gliomas provides an easy and efficient method for non-invasive tumor decoding.

Symptomatic Epileptic Seizures in Patients with Brain Gliomas

Introduction. Epileptic seizures are an important problem that significantly worsens the quality of patients’ life with both newly diagnosed and recurrent brain gliomas.Review. The analysis of domestic and foreign literature showed that low-grade gliomas, this symptom occurs on average in 76%, with high-grade gliomas – in 21% of patients. Despite the maximum allowable tumor resection, it is likely that epileptic seizures persist in 18-64% of patients, and in 5% of patients they first appear in the postoperative period. From 15 to 50% of epileptic seizures in cerebral gliomas are drug-resistant. In patients undergoing chemotherapy, it is better to use new antiepileptic drugs because their cross-effects are minimal.Conclusion. There is no generally accepted algorithm for prescribing and discontinuing antiepileptic drugs in patients with symptomatic epileptic seizures with cerebral gliomas. Further research is needed to determine the optimal combination and dosage regimen of antiepileptic drugs, especially during chemotherapy.

Role of Susceptibility Weighted Images (SWI) in Grading of Brain Glioma

Background Glioma is the most common intracranial primary tumor of central nervous system (CNS) and accounts for about 70% of primary adult malignant brain tumors. The optimum therapeutic treatment and prognosis evaluation largely depends on the tumor pathological grades. Objective To evaluate the role of susceptibility weighted imaging (SWI) in grading of cerebral gliomas. The magnetic resonance imaging (MRI) results were compared and correlated to the pathology results to evaluate its role. The pathological grading of the glioma was done according to WHO 2007 classification system. Patients and Methods This was a retrospective study that included 35 adult patients, (11females & 24 males), their ages ranging from 18 years to 73 years. They were pathologically proven glioma patients ranging from grade I to grade IV. All the patients were referred from neurosurgeon to our radiology center (private center). This study was carried out during the period between January 2017 and November 2018. Results In our study, there were a strong positive correlation between both conventional imaging and pathological grading and between pathological and SWI grading. Using SWI sequence in grading of glioma will be very beneficial in patients with contraindication to contrast. Conclusion SWI using 3T MR system may provide quite useful information for preoperative glioma grading. There seems to be a strong positive correlation between pathological grading and SWI grading system for glioma. The main disadvantage for SWI is the extra time added to the usual time of routine MRI protocol used in cases of intra cranial space occupying lesions (SOL).

Correlation of 11C-Methionine Combined Positron Emission and Computed Tomography and Ki-67 Proliferation Index in Pretreatment Assessment of Cerebral Gliomas

The purpose of the study was to explore the correlation between 11С-methionine (Met) uptake measured by combined positron emission and computed tomography (PET/CT) in newly diagnosed cerebral gliomas and tumor proliferative activity as measured by Ki-67 labeling index (Ki-67 LI).The results of PET/CT with 11С-methionine (PET-Met) of 236 adult patients with pretreated glial brain tumors were included in retrospective analysis. The final diagnosis of glioma according to WHO classification of CNS tumors (2007) was based on both histology and immunohistochemistry using Ki-67 antibodies. On PET-Met tumor-to normal brain uptake ratio (TBR) was calculated by dividing maximum Met uptake in the tumor (hot spot 10 mm in diameter) to activity concentration in the contralateral cortex. The Spearmen rank correlation test was used to analyze the relationships between TBR and Ki-67 LI.PET-Met analysis showed that TBR increases with an increase in the aggressiveness of the glial tumor. The differences of TBR values between gliomas grade II vs III and grade III vs IV were significant (p < 0,001). Among grades II-III gliomas Met uptake was significantly higher in oligodendroglial and mixed gliomas than in astrocytomas (p < 0,001), but the differences did not depend on Ki-67 LI.Correlation analysis demonstrated significant correlation between Ki-67 LI and TBR values (r = 0,49, p < 0,05, Spearman rank test). With analyzing glioma subgroups TBR values correlated with Ki-67 LI in diffuse astrocytomas (r = 0,52, p < 0,05), oligodendrogliomas (r = 0,40, p < 0,05), oligoastrocytomas (r = 0,47, p < 0,05) and in high-grade gliomas (r = 0,45, p < 0,05) but not in low-grade gliomas. Comparison between TBR value and Ki-67 LI in each glioma showed a lack of coincidence in 22 % of cases (high Met uptake but low Ki-67 LI and vice versa). The main reasons for such discrepancies were tumor molecular biology or incorrect biopsy target.Met uptake in diffuse gliomas correlates with proliferative activity which justifies the use of PET-Met for glioma grading. In case of mismatch between two biomarkers one should rely on the indicator that implies a higher aggressiveness of the glioma.