Prognostic relevance of adding MRI data to WHO 2016 and cIMPACT‐NOW updates for diffuse astrocytic tumors in adults. Working toward the extended use of MRI data in integrated glioma diagnosis

Abstract

Assess the contribution of preoperative MRI data in improving grading of adult astrocytomas reclassified according to the WHO 2016 and cIMPACT‐NOW update 3. Retrospective unicentric cohort study of 679 adult patients treated for newly diagnosed diffuse astrocytic and oligodendroglial tumors (January 2006–December 2016). We first systematically compared radiological (contrast enhancement present [CE+] vs. absent [CE−]) and histopathological findings (microvascular proliferation present [MPV+] vs. absent [MPV−]) to validate whether this comparing step of neoangiogenesis represents an efficient method to appreciate the representativity of the tumoral sampling. We focused on 629 cases of astrocytomas for radio‐histological integrated analyses. In 598 cases (95.1%), neoangiogenesis evaluated by MRI or histology (CE+/MPV+ or CE−/MPV−) was identical. For the CE+/MPV− and CE−/MPV+ groups (23 cases), the radio‐histological face‐to‐face evaluation allowed us to assess that for 13 cases (56.5%) the reason for this discrepancy was an undersampled tumor. We analyzed the group of CE+/MPV− (n = 8) and CE−/MPV+ (n = 2) in verified image‐guided tumoral samples. Finally, we identified three new prognostic subgroups for molecular glioblastomas: (1) “non‐representative sampling” (n = 9), (2) “Non neoangiogenic glioblastoma at the time of diagnosis, without contrast enhancement and microvascular proliferation” (n = 8), and (3) “contrast enhancing glioblastoma but without microvascular proliferation in a representative sample” (n = 4). Neoangiogenesis processes should be assessed to improve the prognosis accuracy of the current integrated diagnosis. We suggest adding imaging analyses during the neuropathological analysis of astrocytomas in adults.

Clinico-pathological and epigenetic heterogeneity of diffuse gliomas with FGFR3::TACC3 fusion

“…Minimal imaging data consisted in at least the MRI report and if available, FLAIR and T1 with gadolinium injection MRI sequences. Well-defined ring-enhancement was assessed as present or absent to determine whether cases presented radiologically as high or low grade tumors in order to look for sampling issues in cases of glioblastoma, IDH wildtype as mentioned in Zhang et al [ 27 , 36 ].

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“…Gain of chromosome 7/loss of chromosome 10 was observed and there was mutation of TERT promotor. Scale bars: D, E: 50µm; F, G, H, I: 100 µm [27,36].…”

Clinico-Radio-Histo-Molecular and Neurocognitive Characteristics of Diffuse Gliomas in Adolescent and Young Adults: A Comprehensive Review

“…Grade 4 IDH-wildtype glioblastomas are typically described as ring-like pattern of contrast enhancement lesion with perilesional oedema and mass effect [15]. However, cautions must be taken regarding the new entity proposed by cIMPACT-NOW 3 in 2018, the "diffuse astrocytic glioma, IDH wildtype, with molecular features of glioblastoma," whose imaging appearance can be very heterogeneous, as previously described [17]. Focusing on AYA patients, imaging characteristics of IDH-mutant or Histone-mutant (i.e., H3K27M and H3G34 mutations) HGGs were similar to the paediatric or adult population concerning morphological aspects, pattern of contrast enhancement, and tumour volume [8] (shown in Fig.…”

Prognostic significance of contrast enhancement in newly diagnosed glioblastoma, IDH-wildtype in adults

“…At imaging discovery, glioblastoma, IDH-wildtype typically present with a ring-like pattern of contrast enhancement (CE) area surrounding central necrosis. The presence of a CE is linked to the presence of a microvascular proliferation and is a hallmark for higher-grade diffuse gliomas, which are characterized by neoangiogenesis [14]. In a recent study, the authors demonstrated that the presence of CE and that the pattern of CE (absence, faint and patchy, nodular, and ring-like) signi cantly impacted survival of diffuse astrocytomas [14].…”

“…The presence of a CE is linked to the presence of a microvascular proliferation and is a hallmark for higher-grade diffuse gliomas, which are characterized by neoangiogenesis [14]. In a recent study, the authors demonstrated that the presence of CE and that the pattern of CE (absence, faint and patchy, nodular, and ring-like) signi cantly impacted survival of diffuse astrocytomas [14]. This highlighted its usefulness as an easily available prognostic marker in an integrated grading system [14].…”