Genetically Defined Oligodendroglioma Is Characterized by Indistinct Tumor Borders at MRI

Abstract

BACKGROUND AND PURPOSE:In 2016, the World Health Organization revised the brain tumor classification, making IDH mutation and 1p/19q codeletion the defining features of oligodendroglioma. To determine whether imaging characteristics previously associated with oligodendroglial tumors are still applicable, we evaluated the MR imaging features of genetically defined oligodendrogliomas.

T2–FLAIR Mismatch, an Imaging Biomarker for IDH and 1p/19q Status in Lower-grade Gliomas: A TCGA/TCIA Project

“…LGGs from the TCGA/TCIA and NYU databases distributed by histopathologic assignment and the presence or absence of the T2-FLAIR mismatch sign also more frequently display sharp margins, homogenous internal signal intensity, and lesser degree of contrast enhancement when compared with IDH-wild type lesions (26)(27)(28). IDHmut-Codel and IDHmut-Noncodel gliomas appear to differ with respect to tumor margins and internal heterogeneity (29). Nonetheless, it is generally accepted that conventional MRI findings do not possess sufficient specificity to predict the underlying histologic or molecular subtype of an LGG in an individual patient (30).…”

MRI Features Can Predict 1p/19q Status in Intracranial Gliomas

“…Johnson et al 6 have shown that noncircumscribed borders correlate with 1p/19q codeletion, but given that this appearance was also present in 45% of noncodeleted tumors, this MR imaging feature is not sufficiently specific to predict codeletion with confidence. Rather, to predict 1p/19q status with high specificity, it may be more useful to use circumscribed borders as predictive of a noncodeleted tumor, albeit with limited sensitivity.…”

“…In contrast, the presence of calcification on CT has been found to predict 1p/19q loss of heterozygosity. 5 Noncircumscribed borders have also been shown to correlate with 1p/19q codeletion, occurring in 92% of molecular oligodendrogliomas in a recent series by Johnson et al, 6 but this appearance is not specific because it was also present in 45% of noncodeleted tumors. Other conventional imaging features suggested as being typical of oligodendrogliomas include a cortical-subcortical location, 7 though it is not clear whether this remains true in the current molecular era.…”

Predicting Genotype and Survival in Glioma Using Standard Clinical MR Imaging Apparent Diffusion Coefficient Images: A Pilot Study from The Cancer Genome Atlas

“…4 Finally, the ADC value has previously been reported to predict 1p/19q codeletion status, a marker of oligodendroglioma, in lower grade gliomas. 35,41 In the study by Johnson et al, 41 the ADC values were calculated from sampling both the highest and lowest ADC areas. However, we did not detect a significant correlation between rADC values and 1p/19q codeletion status.…”