R. Souillard-Scemama

Dynamic imaging response following radiation therapy predicts long-term outcomes for diffuse low-grade gliomas.

Quantitative imaging assessment of radiation therapy (RT) for diffuse low-grade gliomas (DLGG) by measuring the velocity of diametric expansion (VDE) over time has never been studied. We assessed the VDE changes following RT and determined whether this parameter can serve as a prognostic factor. We reviewed a consecutive series of 33 adults with supratentorial DLGG treated with first-line RT with available imaging follow-up (median follow-up, 103 months). Before RT, all patients presented with a spontaneous tumor volume increase (positive VDE, mean 5.9 mm/year). After RT, all patients demonstrated a tumor volume decrease (negative VDE, mean, -16.7 mm/year) during a mean 49-month duration. In univariate analysis, initial tumor volume (>100 cm(3)), lack of IDH1 expression, p53 expression, high proliferation index, and fast post-RT tumor volume decrease (VDE at -10 mm/year or faster, fast responders) were associated with a significantly shorter overall survival (OS). The median OS was significantly longer (120.8 months) for slow responders (post-RT VDE slower than -10.0 mm/year) than for fast responders (47.9 months). In multivariate analysis, fast responders, larger initial tumor volume, lack of IDH1 expression, and p53 expression were independent poor prognostic factors for OS. A high proliferation index was significantly more frequent in the fast responder subgroup than in the slow responder subgroup. We conclude that the pattern of post-RT VDE changes is an independent prognostic factor for DLGG and offers a quantitative parameter to predict long-term outcomes. We propose to monitor individually the post-RT VDE changes using MRI follow-up, with particular attention to fast responders.

An update on brain imaging in transient ischemic attack

Neuroimaging is critical in the evaluation of patients with transient ischemic attack (TIA) and MRI is the recommended modality to image an ischemic lesion. The presence of a diffusion (DWI) lesion in a patient with transient neurological symptoms confirms the vascular origin of the deficit and is predictive of a high risk of stroke. Refinement of MR studies including high resolution DWI and perfusion imaging using either MRI or CT further improve the detection of ischemic lesions. Rapid etiological work-up includes non-invasive imaging of cervical and intracranial arteries to search for symptomatic stenosis/occlusion associated with an increased risk of stroke.

Combining intraoperative carmustine wafers and Stupp regimen in multimodal first-line treatment of primary glioblastomas

Abstract Background. The study investigated if intraoperative use of carmustine wafers, particularly in combination with Stupp regimen, is a viable and safe first-line treatment option of glioblastomas. Methods. Eighty-three consecutive adult patients (50 men; mean age 60 years) with newly diagnosed supratentorial primary glioblastomas that underwent surgical resection with intraoperative carmustine wafers implantation (n = 7.1 ± 1.7) were retrospectively studied. Results. The median overall survival (OS) was 15.8 months with 56 patients dying over the course of the study. There was no significant association between the number of implanted carmustine wafers and complication rates (four surgical site infections, one death). The OS was significantly longer in Stupp regimen patients (19.5 months) as compared with patients with other postoperative treatments (13 months; p = 0.002). In addition patients with eight or more implanted carmustine wafers survived longer (24.5 months) than patients with seven or less implanted wafers (13 months; p = 0.021). Finally, regardless of the number of carmustine wafers, median OS was significantly longer in patients with a subtotal or total resection (21.5 months) than in patients with a partial resection (13 months; p = 0.011). Conclusions. The intraoperative use of carmustine wafers in combination with Stupp regimen is a viable first-line treatment option of glioblastomas. The prognostic value of this treatment association should be evaluated in a multicenter trial, ideally in a randomized and placebo-controlled one.

Neuronal immunoexpression and a distinct subtype of adult primary supratentorial glioblastoma with a better prognosis

OBJECT In this study, the authors address whether neurofilament protein (NFP) expression can be used as an independent prognostic factor in primary glioblastoma multiformes (GBMs). METHODS Three hundred and two consecutive adult patients with newly diagnosed supratentorial primary GBMs were analyzed (January 2000-August 2008). Detailed data regarding clinical, imaging, and pathological findings, oncological treatments, and outcomes were recorded. Neurofilament protein immunoexpression served to identify NFP-positive tumor cells (normal entrapped neurons and mature ganglion-like cells excluded). RESULTS Neurofilament-positive cells were identified in 177 GBMs (58.6%). Patients with NFP-positive GBMs were younger (p < 0.0001), and their GBMs presented with more temporal lobe tumor localization (p = 0.029) and more cortical involvement (p = 0.0003). Neurofilament-negative GBMs presented with more ventricular contact (p < 0.0001) and more tumor midline crossing (p = 0.03). Median overall survival and progression-free survival (PFS) were 13.0 and 7.6 months, respectively, for NFP-positive GBMs, and 7.0 and 5.1 months, respectively, for NFP-negative GBMs. Multivariate analysis revealed NFP immunoexpression, tumor midline crossing, complete resection, and radiotherapy combined with chemotherapy as independent factors associated with overall survival. Neurofilament protein-positive immunoexpression was associated with longer overall survival (hazard ratio [HR] 0.54, 95% CI 0.40-0.74; p < 0.0001) and longer PFS (HR 0.71, 95% CI 0.53-0.96; p = 0.02). CONCLUSIONS Neurofilament protein-positive immunoexpression represents a strong, therapeutically independent prognostic factor for primary supratentorial GBM clinical outcome among adult patients. Neurofilament protein-GBMs unique pathological features are not only associated with distinct clinical and anatomical behavior, but are also predictive of overall patient survival and PFS. Neurofilament protein immunoexpression may help identify a distinct subgroup of primary GBMs with a favorable prognosis, which should be considered in the design of future targeted therapies.

Imaging of gliomas at 1.5 and 3 Tesla - A comparative study

BACKGROUND Glioma follow-up is based on MRI parameters, which are correlated with survival. Although established criteria are used to evaluate tumor response, radiological markers may be confounded by differences in instrumentation including the magnetic field strength. We assessed whether MRIs obtained at 3 Tesla (T) and 1.5T provided similar information. METHODS We retrospectively compared imaging features of 30 consecutive patients with WHO grades II and III gliomas who underwent MRI at 1.5T and 3T within a month of each other, without any clinical changes during the same period. We compared lesion volumes on fluid attenuation inversion recovery (FLAIR), ratio of cerebral blood volume (rCBV) on perfusion-weighted imaging, contrast-to-noise ratio (CNR) on FLAIR, and on post-gadolinium 3D T1-weighted sequences between 1.5T and 3T using intraclass correlation coefficient (ICC). Concordance between observers within and between modalities was evaluated using weighted-kappa coefficient (wκ). RESULTS The mean ± SD delay between modalities (1.5T and 3T MRI) was 8.6 ± 5.6 days. Interobserver/intraobserver concordance for lesion volume was almost perfect for 1.5T (ICC = 0.96/0.97) and 3T (ICC = 0.99/0.98). Agreement between observers for contrast enhancement was excellent at 1.5T (wκ = 0.92) and 3T (wκ = 0.92). The tumor CNR was significantly higher for FLAIR at 1.5T (P < .001), but it was higher at 3T (P = .012) for contrast enhancement. Correlations between modalities for lesion volume (ICC = 0.97) and for rCBV values (ICC = 0.92) were almost perfect. CONCLUSIONS In the follow-up of WHO grades II and III gliomas, 1.5T and 3T provide similar MRI features, suggesting that monitoring could be performed on either a 1.5 or a 3T MR magnet.

Presentation and management of lateral sinus thrombosis following posterior fossa surgery

OBJECTIVE There are no guidelines for the management of postoperative lateral sinus thrombosis following posterior fossa surgery. Introducing treatment-dose anticoagulant therapy during the immediate postoperative period increases the risk of intracranial bleeding. This study assessed the incidence of and risk factors associated with postoperative lateral sinus thrombosis and the complications related to thrombosis and/or anticoagulation. METHODS This study was a retrospective monocentric analysis of adult patients who underwent surgical removal of a posterior fossa space-occupying lesion with available postoperative imaging. Postoperative lateral sinus thrombosis was defined as a T2* hypointensity within the venous sinus and/or a filling defect on postcontrast MRI or CT scan. RESULTS Among 180 patients, 12 (6.7%; 95% CI 3.0-10.4) were found to have lateral sinus thrombosis on postoperative imaging, none of whom were symptomatic. Unadjusted risk factors for postoperative lateral sinus thrombosis were a history of deep venous thrombosis (p = 0.016), oral contraceptive pill (p = 0.004), midline surgical approach (p = 0.035), and surgical exposure of the sinus (p < 0.001). Seven of the patients (58.3%) with a postoperative lateral sinus thrombosis received immediate treatment-dose anticoagulant therapy. Lateral sinus recanalization occurred radiologically at a mean time of 272 ± 23 days in 85.7% of patients (6 of 7) undergoing treatment-dose anticoagulant therapy and in 20% of patients (1 of 5) not receiving treatment-dose anticoagulant therapy. Postoperative complications occurred in 56.2% of patients (9 of 16) who received treatment-dose curative anticoagulant therapy and in 27% of patients (45 of 164) who did not. CONCLUSIONS Incidental radiological lateral sinus thrombosis following posterior fossa surgery has an incidence of 6.7%. To further define the benefit-to-risk ratio of a treatment-dose anticoagulant therapy, a prospective trial should be considered.

MR imaging of the brain and spinal cord in lymphomatoid granulomatosis: A case report and review of the literature

Journal of Neuroradiology - In Press.Proof corrected by the author Available online since samedi 6 avril 2013

Solitary lytic skull lesion revealing an eosinophilic granuloma in an adult

Journal of Neuroradiology - In Press.Proof corrected by the author Available online since mardi 17 aout 2010