J Neurol Surg B Skull Base 2016; 77 - LFP-01-03
DOI: 10.1055/s-0036-1592563

Evaluation of Radiological Indicators of Surgical Plane of Meningiomas

Sivashanmugam Dhandapani 1, Karthigeyan Madhivanan 1, Pravin Salunke 1, Paramjeet Singh 1, Bishan D. Radotra 1, Sunil K. Gupta 1
  • 1Departments of Neurosurgery, Radiology and Pathology, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, India

The study was to objectively assess radiological indicators in conventional MR sequences with respect to operative findings and tumor interface during surgical resection of meningiomas. Signal intensity of meningioma on T1, T2, FLAIR, and contrast MR sequences were prospectively noted and analyzed in relation to intraoperative tumor consistency, vascularity, dissection plane, Simpson’s grade of excision, and histopathology. Appropriate univariate and multivariate analysis were performed. Of the total 70 patients (44 females, 26 males), 18 had skull base, 15 had convexity, 10 had parasagittal, 11 had falcine, and 7 had tentorial meningiomas. Majority (67) had tumors which were hypo to isointense in T1. While 14 had hypointense signal in T2, only 8 were hypointense in FLAIR. 21 had inhomogeneous enhancement. 28 had marked tumor interface in MRI, while 33 and 9 had regular and irregular border, respectively. 19 had no edema, while 33 and 18 had focal and lobar edema respectively. Inhomogeneous enhancement (p = 0.01) and FLAIR hypointensity (p = 0.03) had significant association with tumor hardness. FLAIR hypointensity (p = 0.01) had significant association with low vascularity. Skull base location (p = 0.04), FLAIR hypointensity (p = 0.02), irregular border (p = 0.01), and recurrence (p = 0.01) had significant association with subpial or mixed plane of cleavage. Only skull base location (p = 0.01) had significant impact on extent of excision. T2 hypointensity (p = 0.001) and FLAIR hypointensity (p = 0.01) had significant association with Fibroblastic or Psammomatous meningioma. In multivariate analysis, FLAIR hypointensity (p = 0.02) and skull base location (p = 0.04) had significant independent association with suboptimal surgical plane, while skull base location (p = 0.01) had significant association with extent of excision. Among MRI sequences, FLAIR hypointensity had the best performance characteristic with specificity of 94% to predict suboptimal surgical plane. In conclusion, FLAIR images correlate with suboptimal surgical plane during resection of meningioma with high specificity.