Advanced MRI shape analysis as a predictor of histologically aggressive supratentorial meningioma.

BACKGROUND AND PURPOSE: A subset of aggressive meningioma is associated with higher morbidity and requires a different therapeutic management. This subset consists of World Health Organization (WHO) grade II and III meningioma, characterized particularly with microscopic brain invasion. Numerous studies tried to screen aggressive meningioma on pre-operative MRI. The objective of the study was to determine if an advanced shape analysis of supratentorial meningioma outlines could reliably predict WHO II-III grade and histological brain invasion. MATERIALS AND METHODS: We performed a retrospective analysis for all consecutive patients who underwent surgery for supratentorial histologically-proven meningioma from 2010 to 2018. Pre-operative MRI T1WI contrast enhanced axial, coronal and sagittal slices were collected from 101 patients. Advanced shape analysis including fractal analysis and topological skeleton analysis was performed. Shape analysis parameters were correlated with histopathological WHO grading and brain invasion on surgical pieces. RESULTS: Shape analysis features such as a low circularity, a low solidity, a high fractal dimension and a high number of skeleton's branches were significantly correlated with both WHO II-III meningioma and histological brain invasion. Cross-validated regression models including these features were predictive of WHO II-III meningioma and brain invasion with respective AUC of 0.71 and 0.72. CONCLUSIONS: MRI shape analysis provides informative imaging biomarkers to predict high WHO grade and histological brain invasion of supratentorial meningioma. Further prospective studies including the evaluation of a fully-automatized and totally reproducible process are required to confirm the results.

Pre-surgical embolization of intracranial meningioma with Onyx: A safety and efficacy study.

BACKGROUND AND PURPOSE: Pre-surgical embolization of large intracranial meningioma has been demonstrated to decrease blood loss and to improve the resectability of the tumor. Few reports have evaluated the risk and benefits of using Onyx in this indication. The objective of our study was to assess the efficiency and safety of pre-surgical embolization in a consecutive series of intracranial meningioma using Onyx. MATERIALS AND METHODS: We conducted a retrospective study of consecutive patients treated from 2010 to 2018 with pre-surgical embolization with Onyx for intracranial histologically-proven meningioma. Safety was evaluated by a report of the complications related to the procedure while efficacy was assessed on angiographic and histopathologic criteria. RESULTS: Forty-four meningioma in 44 patients treated with pre-surgical embolization were included in this study. Proximal artery occlusion was obtained in 97.6% (41/42) of the cases and good intra-tumoral penetration was achieved in 75.6% (31/41). Embolic agent inside blood vessels was identified in 63.5% (28/44) of cases. Embolization-induced necrosis was present in 79.6% (35/44) of cases. Six complications have been encountered (13.6%); 3 were stated as minor complications (6.8%) and 3 as major occurring in case of trans-ophthalmic route (6.8%). CONCLUSIONS: The present work is to date the largest study to evaluate intracranial meningioma embolization using Onyx. Onyx's allowed good intra-tumoral penetration and proximal artery occlusion in most cases but carries a higher risk of complication in case of ophthalmic supply.

MRI predictive score of pial vascularization of supratentorial intracranial meningioma.

OBJECTIVE: Meningiomas are highly vascularized tumors which may recruit pial blood supply. Pial supply complicates tumor treatment in numerous ways. The objective of this study was to establish a reliable MRI-based diagnostic score to predict the existence of pial blood supply in supratentorial intracranial meningiomas and then correlate the score with clinical and surgical outcomes and histopathological findings. METHODS: We performed a retrospective analysis of supratentorial histologically proven meningiomas in our institution from 2010 to 2018. A score was built based on MRI criteria and correlated with digital subtraction angiography (DSA) pial vascularization assessment. The score was then validated on a second independent population recruited with the same modalities. RESULTS: Logistic regression identified four parameters related to pial blood supply which were used to build the score: skull base location, tumor size > 45 mm, peritumoral flow voids, and incomplete cerebrospinal fluid rim. The overall diagnostic performance in predicting pial blood supply was as follows: sensitivity 97.8%, specificity 76.9%, predictive positive value 88.2%, negative predictive value 95.2%, and accuracy 90.3%. Inter-reader agreement and Cohen's kappa were good, respectively, of 90.7% and 0.69. A high score was associated with aggressive meningioma (World Health Organization II-III) (p = 0.04) and with greater importance of pial supply relative to dural supply. CONCLUSIONS: We have identified a reliable way to use MRI to predict the existence of pial blood supply in supratentorial intracranial meningiomas. A higher score also predicted higher grade meningioma. KEY POINTS: • Accurate and reproducible MRI score composed of four items to predict the existence of pial blood supply in supratentorial meningioma. • High score is associated with high-grade meningioma (WHO II-III) but also with greater importance of pial supply relative to dural supply.

Isolated cerebral Rosai-Dorfman disease presenting as a sole mass protruding into the fourth ventricle: A case report.

Rosai-Dorfman disease is a non-Langherans cell histiocytosis typically revealed by a lymphadenopathy. Central nervous system involvement is rare, exceptionally isolated, and usually consists of dural masses mimicking meningioma. Very few reports have described non-dural-based lesions, especially with an intra-ventricular development. We report hereby the case of a Rosai-Dorfman disease in a 30-year-old man presenting as an isolated mass arising from the right cerebellar peduncle and protruding into the fourth ventricle. We provide the results of the MRI examination with a special focus on advanced MRI features. As the diagnosis relies on pathological examination, we also detail the results of the analysis that followed the surgical resection of the mass including the immunohistochemical profile. This report highlights the necessity to consider Rosai-Dorfman disease as a potential diagnosis in case of an infra-tentorial mass and/or intra-ventricular mass.