Central nervous system tumors: Spotlight on India

Deep CNNs for glioma grading on conventional MRIs: Performance analysis, challenges, and future directions

The increasing global incidence of glioma tumors has raised significant healthcare concerns due to their high mortality rates. Traditionally, tumor diagnosis relies on visual analysis of medical imaging and invasive biopsies for precise grading. As an alternative, computer-assisted methods, particularly deep convolutional neural networks (DCNNs), have gained traction. This research paper explores the recent advancements in DCNNs for glioma grading using brain magnetic resonance images (MRIs) from 2015 to 2023. The study evaluated various DCNN architectures and their performance, revealing remarkable results with models such as hybrid and ensemble based DCNNs achieving accuracy levels of up to 98.91%. However, challenges persisted in the form of limited datasets, lack of external validation, and variations in grading formulations across diverse literature sources. Addressing these challenges through expanding datasets, conducting external validation, and standardizing grading formulations can enhance the performance and reliability of DCNNs in glioma grading, thereby advancing brain tumor classification and extending its applications to other neurological disorders.

99mTc-Methionine Hybrid SPECT/CT for Detection of Recurrent Glioma: Comparison With 18F-FDG PET/CT and Contrast-Enhanced MRI

OBJECTIVES

Posttherapy changes in treated glioma patients cannot be reliably differentiated from tumor recurrence. We evaluated the role of Tc-methionine SPECT/CT for the detection of recurrent glioma and compared the same with F-FDG PET/CT and contrast-enhanced MRI (CeMRI).

METHODS

Forty-four patients with histologically proven, previously treated glioma and clinical suspicion of recurrence were prospectively enrolled in the study. Of these 44 patients, 39 (28 male and 11 female subjects; age, 38.05 ± 9.7 years) underwent Tc-methionine SPECT/CT, F-FDG PET/CT, and CeMRI of the brain and were included for final analysis. Combination of repeat imaging, biopsy, and/or clinical follow-up (6-36 months) was taken as reference standard. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated. Diagnostic values among modalities were compared.

RESULTS

Positive predictive value and negative predictive value for Tc-methionine SPECT/CT, F-FDG PET/CT, and CeMRI were 95.6% and 56.2%, 92.3% and 61.5%, and 79.4% and 42.9%, respectively. Sensitivity and specificity for the 3 modalities were 75.9% and 90%, 82.8% and 80%, and 87.1% and 30%. Specificity of Tc-methionine SPECT/CT was significantly higher than that of CeMRI (P < 0.0001) but not of F-FDG PET/CT (P = 0.36). No significant difference was seen between the modalities for sensitivity and accuracy.

CONCLUSIONS

Tc-methionine is a promising tracer for detection of recurrent glioma. Diagnostic values of Tc-methionine SPECT/CT are similar to F-FDG, although it is more specific than CeMRI. So it may be used as a cost-effective alternative and also where PET/CT is not available.

CD47 Promotes Human Glioblastoma Invasion Through Activation of the PI3K/Akt Pathway

Cluster of differentiation 47 (CD47) overexpression is common in various malignancies. This study investigated whether CD47 promotes human glioblastoma invasion and, if so, the underlying mechanisms involved. CD47 expression was found to be stronger in tissues of patients with glioblastoma and in various cancer cell lines than in normal controls. CD47 downregulation via siRNA suppressed invasion in vitro, whereas CD47 overexpression through plasmid transfection exerted the opposite effect. However, overexpression or knocking down of CD47 had no effect on cell proliferation. Moreover, CD47 expression was related to Akt phosphorylation at the cellular molecular level. Suppression of Akt with a specific inhibitor impaired the invasion ability of CD47-overexpressing cells, indicating that stimulation of the PI3K/Akt pathway served as the downstream regulator of CD47-triggered invasion. These results suggest that CD47 might be a useful predictor of poor prognosis and metastasis and a potential target for treating glioblastomas.