Imaging Characteristics of Oligodendrogliomas That Predict Grade

Abstract

BACKGROUND AND PURPOSE Oligodendrogliomas are tumors that have variable WHO grades depending on anaplasia and astrocytic components and their treatment may differ accordingly. Our aim was to retrospectively evaluate imaging features of oligodendrogliomas that predict tumor grade. MATERIALS AND METHODS The imaging studies of 75 patients with oligodendrogliomas were retrospectively reviewed and compared with the histologic grade. The presence and degree of enhancement and calcification were evaluated subjectively. rCBV and ADC maps were measured. Logistic linear regression models were used to determine the relationship between imaging factors and tumor grade. RESULTS Thirty of 75 (40%) tumors enhanced, including 9 of 46 (19.6%) grade II and 21 of 29 (72.4%) grade III tumors (P <.001). Grade III tumors showed lower ADC values compared with grade II tumors (odds ratio of a tumor being grade III rather than grade II = 0.07; 95% CI, 0.02–0.25; P =.001). An optimal ADC cutoff of 925 10−6 mm2/s was established, which yielded a specificity of 89.1%, sensitivity of 62.1%, and accuracy of 78.7%. There was no statistically significant association between tumor grade and the presence of calcification and perfusion values. Multivariable prediction rules were applied for ADC < 925 10−6 mm2/s, the presence of enhancement, and the presence of calcification. If either ADC < 925 10−6 mm2/s or enhancement was present, it yielded 93.1% sensitivity, 73.9% specificity, and 81.3% accuracy. The most accurate (82.2%) predictive rule was seen when either ADC < 925 10−6 mm2/s or enhancement and calcification were present. CONCLUSIONS Models based on contrast enhancement, calcification, and ADC values can assist in predicting the grade of oligodendrogliomas and help direct biopsy sites, raise suspicion of sampling error, and predict prognosis.

A Conflicting Case of Childhood Oligodendroglioma

“…Childhood meningiomas also appear as cystic and calcified intracranial masses (4). The use of SWI in the detection of calcification as hypointense areas has been reported in the literature; however, CT is superior in detecting calcifications (4). In this case, the lesion was hypointense in SWI sequences and isointense in T1WIs and T2WIs, which are pathognomonic for calcification.…”

“…Among intra-axial brain tumors, oligodendrogliomas have the highest frequency of calcification (approximately 80%). Childhood meningiomas also appear as cystic and calcified intracranial masses (4). The use of SWI in the detection of calcification as hypointense areas has been reported in the literature; however, CT is superior in detecting calcifications (4).…”

Anaplastic Oligodendroglioma in an Adolescent Male; A rare case Report and Review of the Literature

“…Most oligodendrogliomas manifest in the adult age groups with a peak incidence in the fourth and fifth decades [6][7][8] . The tumors account for less than 1% of paediatric central nervous system neoplasms [13][14][15] with a child: adult ratio approx. 1:8 [16] .…”

Oligodendroglial Tumors

“…38 In general, the survival of the patients with non-codeleted, non-IDH mutated anaplastic oligodendroglioma or mixed oligoastrocytoma is similar to those patients with Tumor calcification and perfusion characteristics do not appear to reliably define tumor grade. 41 Codeleted tumors are typically smaller in dimension than non-codeleted tumors (p=0.008), and more often are confined to a single lobe (p=0.023), and show more intratumoral T1 and T2 signal heterogeneity than non-codeleted tumors. 42,43 Radiographic pseudoprogression is relatively common in irradiated oligodendroglial tumors.…”