Low-grade gliomas: The challenges of imaging

Guillevin, Rémy; Herpe, Guillaume; Verdier, M; Guillevin, Carole

doi:10.1016/j.diii.2014.07.005

Cited by 24 publications

(16 citation statements)

References 30 publications

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“…Integration of some clinico-radiological criteria with histology is commonly performed for the diagnosis of brain gliomas [20,49]. In the present study, we observed that these criteria were not helpful for IMAs.…”

Section: Discussionmentioning

confidence: 52%

Clinical, radiological and molecular characterization of intramedullary astrocytomas

Lebrun¹,

Meléndez²,

Blanchard³

et al. 2020

acta neuropathol commun

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Intramedullary astrocytomas (IMAs) are rare tumors, and few studies specific to the molecular alterations of IMAs have been performed. Recently, KIAA1549-BRAF fusions and the H3F3A p.K27M mutation have been described in low-grade (LG) and high-grade (HG) IMAs, respectively. In the present study, we collected clinico-radiological data and performed targeted next-generation sequencing for 61 IMAs (26 grade I pilocytic, 17 grade II diffuse, 3 LG, 3 grade III and 12 grade IV) to identify KIAA1549-BRAF fusions and mutations in 33 genes commonly implicated in gliomas and the 1p/19q regions. One hundred seventeen brain astrocytomas were analyzed for comparison. While we did not observe a difference in clinico-radiological features between LG and HG IMAs, we observed significantly different overall survival (OS) and event-free survival (EFS). Multivariate analysis showed that the tumor grade was associated with better OS while EFS was strongly impacted by tumor grade and surgery, with higher rates of disease progression in cases in which only biopsy could be performed. For LG IMAs, EFS was only impacted by surgery and not by grade. The most common mutations found in IMAs involved TP53, H3F3A p.K27M and ATRX. As in the brain, grade I pilocytic IMAs frequently harbored KIAA1549-BRAF fusions but with different fusion types. Noncanonical IDH mutations were observed in only 2 grade II diffuse IMAs. No EGFR or TERT promoter alterations were found in IDH wild-type grade II diffuse IMAs. These latter tumors seem to have a good prognosis, and only 2 cases underwent anaplastic evolution. All of the HG IMAs presented at least one molecular alteration, with the most frequent one being the H3F3A p.K27M mutation. The H3F3A p.K27M mutation showed significant associations with OS and EFS after multivariate analysis. This study emphasizes that IMAs have distinct clinico-radiological, natural evolution and molecular landscapes from brain astrocytomas.

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Section: Discussionmentioning

confidence: 52%

Clinical, radiological and molecular characterization of intramedullary astrocytomas

Lebrun¹,

Meléndez²,

Blanchard³

et al. 2020

acta neuropathol commun

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“…The limited ability for FDG‐PET/CT, even in combination with MRI, to differentiate between grade II and grade III glioma is associated with treatment and prognostication impacts . There was notable disconcordance between MRI and FDG‐PET/CT in this group.…”

Section: Discussionmentioning

confidence: 99%

“…The contribution of MRI to the disconcordance may be due to a proportion of glioma not enhancing with contrast and substantial overlap of ADCs between differing grades . The failure to enhance and overlap of ADCs may be multifactorial and influenced by the tumour microenvironment, cellularity, blood diffusion, oedema and disruption of the blood–brain barrier . These factors may also alter glucose uptake for FDG‐PET/CT where we would normally expect it to be greater in high‐grade glioma as compared to low‐grade (hypometabolic) glioma …”

Section: Discussionmentioning

confidence: 99%

Diagnostic performance of 18F‐fluorodeoxyglucose positron emission tomography in the evaluation of glioma

et al. 2019

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Introduction: Identifying glioma grade through imaging allows clinicians to recommend and accurately direct treatment. We sought to quantify the utility of FDG-PET/CT (18F-fluorodeoxyglucose positron emission tomography/computed tomography), alone and in combination with MRI, in identifying highgrade regions of glioma. Methods: This is a retrospective review of patients who had an FDG-PET/CT performed as part of the workup of suspected glioma or in follow-up of known glioma. FDG-PET/CT scans were reviewed and uptake in the identifiable lesion coded as none, diffusely or focally increased. Patients also underwent gadolinium-enhanced MRI, noting regions of contrast enhancement. Sensitivity, specificity, positive and negative predictive values (PPV and NPV) were calculated for identification of high-grade histology (WHO III or IV, or metastatic disease) obtained post-FDG-PET/CT. Results: Thirty-three patients had 36 FDG-PET/CT and MRI scans followed by histological confirmation (biopsy or debulking). Increased FDG uptake demonstrated a sensitivity of 59% and specificity of 79%, PPV of 81% and NPV of 55% for identification of high-grade histology. MRI demonstrated a sensitivity of 77% and specificity of 86%, PPV of 89% and NPV of 71% for identification of highgrade histology. Only 64% of MRI and FDG-PET/CT scan series were concordant. When FDG-PET/CT and MRI were concordant, a specificity of 100% and PPV of 100% was achieved, however, sensitivity was 79% and NPV was 75%. Conclusion: The combination of FDG-PET/CT and gadolinium-enhanced MRI demonstrated marked improvement in identifying potential high-grade disease over each modality alone. Increased FDG uptake without gadolinium enhancement rarely occurred and identified high-grade histology in a small number of patients. Due to limited sensitivity and NPV, a negative FDG-PET/ CT alone, or in combination with MRI, should not guide a decision for observation where surgery would otherwise be recommended.

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“…However, after radiation, differentiation of post-treatment enhancement on MR and tumor progression for low-grade gliomas becomes challenging due to their delayed malignant transformation and potential for radiation necrosis13). Use of perfusion imaging in these low-grade tumors may detect malignant transformation with reasonable accuracy.…”

Section: Discussionmentioning

confidence: 99%

The Use of MR Perfusion Imaging in the Evaluation of Tumor Progression in Gliomas

Snelling

Shah

Buttrick

et al. 2017

J Korean Neurosurg Soc

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ObjectiveDiagnosing tumor progression and pseudoprogression remains challenging for many clinicians. Accurate recognition of these findings remains paramount given necessity of prompt treatment. However, no consensus has been reached on the optimal technique to discriminate tumor progression. We sought to investigate the role of magnetic resonance perfusion (MRP) to evaluate tumor progression in glioma patients.MethodsAn institutional retrospective review of glioma patients undergoing MRP with concurrent clinical follow up visit was performed. MRP was evaluated in its ability to predict tumor progression, defined clinically or radiographically, at concurrent clinical visit and at follow up visit. The data was then analyzed based on glioma grade and subtype.ResustsA total of 337 scans and associated clinical visits were reviewed from 64 patients. Sensitivity, specificity, positive and negative predictive value were reported for each tumor subtype and grade. The sensitivity and specificity for high-grade glioma were 60.8% and 87.8% respectively, compared to low-grade glioma which were 85.7% and 89.0% respectively. The value of MRP to assess future tumor progression within 90 days was 46.9% (sensitivity) and 85.0% (specificity).ConclusionBased on our retrospective review, we concluded that adjunct imaging modalities such as MRP are necessary to help diagnose clinical disease progression. However, there is no clear role for stand-alone surveillance MRP imaging in glioma patients especially to predict future tumor progression. It is best used as an adjunctive measure in patients in whom progression is suspected either clinically or radiographically.

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Low-grade gliomas: The challenges of imaging

Cited by 24 publications

References 30 publications

Clinical, radiological and molecular characterization of intramedullary astrocytomas

Clinical, radiological and molecular characterization of intramedullary astrocytomas

Diagnostic performance of 18F‐fluorodeoxyglucose positron emission tomography in the evaluation of glioma

The Use of MR Perfusion Imaging in the Evaluation of Tumor Progression in Gliomas

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