Prognostic and predictive values of diffusion and perfusion MRI in paediatric intracranial ependymomas in a large national study

Abstract

Objective: To assess the relative cerebral blood volume (rCBV) and apparent diffusion coefficient (ADC) derived, respectively, from perfusion and diffusion pre-operative MRI of intracranial ependymomas and their predictive and prognostic values. Methods: Pre-operative MRI and clinical data for intracranial ependymomas diagnosed between January 2000 and December 2013 were retrospectively retrieved from a web-based national database. MRI data included diffusion (62 patients) and perfusion (20 patients) MRI. Patient age, histopathological diagnosis, tumour location, ADC, relative ADC (rADC) and rCBV were considered as potential factors in a survival analysis. Survival rates were estimated using the Kaplan-Meier method. Univariate analyses were performed using the log-rank test to compare groups. We also performed a multivariate analysis, applying the Cox proportional hazards model.Results: ADC and rADC values within hypointense regions differed significantly between grades II and III (p 5 0.01). The 75th percentile of ADC within hypointense regions and the 25th percentile of rCBV within nonenhancing lesions were prognostic of disease-free survival (p 5 0.004, p 5 0.05). A significant correlation was found between the 75th percentile of rCBV and the 25th percentile of rADC (p 5 0.01) in enhancing regions of grade-III tumours. Conclusion: Pre-operative rADC and rCBV could be used as prognostic factors for clinical outcome and to predict histological grade in paediatric ependymomas. Advances in knowledge: Prognostic value of diffusion and perfusion MRI in paediatric ependymoma was found and may play a role in the prognostic classification of patients in order to design more tailored treatment strategies.

MRI Features of Intracranial Anaplastic Ependymomas: A Comparison of Supratentorial and Infratentorial Lesions

“…The current study demonstrated that on DWI, almost all solid tissues of SAEs appeared hyperintense, whereas IAEs exhibited iso-hypointense signals. This result conformed to the histological and clinical outcome differences between SAEs and IAEs (1,10,16,22). Peritumoral edema commonly occurred when parenchymal involvement was noted.…”

“…Diffusion restriction was regarded as a characteristic of high-grade tumors and poorer prognostic factors for clinical outcome (10,25). The current study demonstrated that on DWI, almost all solid tissues of SAEs appeared hyperintense, whereas IAEs exhibited iso-hypointense signals.…”

Multiparametric Analysis of Permeability and ADC Histogram Metrics for Classification of Pediatric Brain Tumors by Tumor Grade

“…Other studies have demonstrated the advantage of combinations of DWI, DSC perfusion, MR spectroscopy, and PET data in studying pediatric brain tumors. [18][19][20] To our knowledge, this is the first study to demonstrate a multiparametric approach using DCE and ADC histogram metrics in pediatric brain tumors.…”

EANO guidelines for the diagnosis and treatment of ependymal tumors

“…8 Perfusion MRI may display elevated cerebral blood volume values and have some prognostic value. 18 Spinal cord ependymomas display more distinct borders than diffuse astrocytomas. 14 Cyst formation and T2 hypointensity of the cyst wall due to blood products ("hemosiderin cap") are suggestive of ependymoma.…”