Advanced Diagnosis of Glioma by Using Emerging Magnetic Resonance Sequences

Abstract

Glioma, the most common primary brain tumor in adults, can be difficult to discern radiologically from other brain lesions, which affects surgical planning and follow-up treatment. Recent advances in MRI demonstrate that preoperative diagnosis of glioma has stepped into molecular and algorithm-assisted levels. Specifically, the histology-based glioma classification is composed of multiple different molecular subtypes with distinct behavior, prognosis, and response to therapy, and now each aspect can be assessed by corresponding emerging MR sequences like amide proton transfer-weighted MRI, inflow-based vascular-space-occupancy MRI, and radiomics algorithm. As a result of this novel progress, the clinical practice of glioma has been updated. Accurate diagnosis of glioma at the molecular level can be achieved ahead of the operation to formulate a thorough plan including surgery radical level, shortened length of stay, flexible follow-up plan, timely therapy response feedback, and eventually benefit patients individually.

A Systematic Review of the Current Status and Quality of Radiomics for Glioma Differential Diagnosis

“…Concerning clinical aspects, glioma predominantly manifests with neurological signs, which can also be encountered in other neoplastic and nonneoplastic lesions such as brain inflammation, abscess, lymphoma, or brain metastasis [ 4 , 5 ].…”

“…On MRI, PCNSL and high-grade gliomas share structural overlaps and anatomical similarities, both of which show contrast-enhancing lesions with peritumoral edema [ 10 ]. Similarly, distinguishing a glioma from brain metastasis is another clinical challenge, not only because of the similar symptoms of these conditions but also due to their very similar appearance on conventional MRI sequences as solitary, highly enhancing brain tumors surrounded by a T2-hyperintense edema [ 4 , 11 ].…”

“…For example, distinguishing brain parenchyma inflammation from grade II glioma can be difficult for neuroradiologists since both inflammation and glioma appear on conventional MRI sequences as lesions with a mass effect. Moreover, they have similar properties on specific sequences, such as hypointensity on T1-w, hyperintensity on T2-w, and no enhancement on postcontrast T1-CE [ 4 , 12 ].…”

Ultra-High-Field MRI in the Diagnosis and Management of Gliomas: A Systematic Review

“…This characterization is especially important to the treatment of highly aggressive tumors, such as glioblastoma (GBM), which has a <5% 5-year survival probability ( 4 ). Presently, tissue biopsy is required for tumor grading and genotyping whereby assessment of glial fibrillary acidic protein production, isocitrate dehydrogenase 1 (IDH) mutational status, presence of 1p/19q codeletion, epidermal growth factor receptor (EGFR) expression, E3 ubiquitin-protein-ligase-Mdm2 encoding gene mutation status, and other neoplastic changes within gliomas enables the more robust characterization that is critical to the development of individualized treatment associated with improved clinical outcomes ( 2 – 4 ). For example, IDH mutations have improved survival outcomes compared to IDH-wildtype (WT) ( 5 ), and O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation is a favorable prognostic factor in GBM ( 6 ).…”

“…Advances in low field MRI acquisition and processing, including innovative uses of diffusion-weighted imaging (DWI) and magnetic resonance spectroscopic imaging (MRS/I) algorithms, have enabled both more accurate delineation of tumors margins and pre-operative assessment of biomolecular characteristics associated with gliomas that was previously only feasible through histologic assessment of biopsied brain tissue. These imaging sequences, along with numerous other advancements ( 4 ), have demonstrated the ability of MRI to provide information for enhanced tumor characterization and improved predictions of treatment efficacy that traditionally relied on surgical biopsy.…”