Response assessment in paediatric intracranial ependymoma: recommendations from the Response Assessment in Pediatric Neuro-Oncology (RAPNO) working group.

Response criteria for paediatric intracranial ependymoma vary historically and across different international cooperative groups. The Response Assessment in the Pediatric Neuro-Oncology (RAPNO) working group, consisting of an international panel of paediatric and adult neuro-oncologists, neuro-radiologists, radiation oncologists, and neurosurgeons, was established to address both the issues and the unique challenges in assessing the response in children with CNS tumours. We established a subcommittee to develop response assessment criteria for paediatric ependymoma. Current practice and literature were reviewed to identify major challenges in assessing the response of paediatric ependymoma to clinical trial therapy. For areas in which data were scarce or unavailable, consensus was reached through an iterative process. RAPNO response assessment recommendations include assessing disease response on the basis of changes in tumour volume, and using event-free survival as a study endpoint for patients entering clinical trials without bulky disease. Our recommendations for response assessment include the use of brain and spine MRI, cerebral spinal fluid cytology, neurological examination, and steroid use. Baseline postoperative imaging to assess for residual tumour should be obtained 24-48 h after surgery. Our consensus recommendations and response definitions should be prospectively validated in clinical trials.

Does black blood MRA have a role in the assessment of intracerebral aneurysms?

The aim of this study was to assess whether the addition of a black blood (BB) sequence to standard three-dimensional time-of-flight (3D-TOF) imaging yields improved quantitative assessment of intracranial aneurysms. Thirty seven patients with 42 proven intracranial aneurysms underwent intra-arterial digital subtraction angiography, 3D-TOF and BB MRI imaging. This multimodality imaging was used to create a composite reference aneurysm description. The 3D-TOF and BB imaging were graded on a subjective seven-point scale to determine what improvement if any the addition of BB imaging yielded. Comparison of measurements from all imaging modalities demonstrated no significant difference (p < 0.01) in aneurysm length/width or parent vessel width. Aneurysm neck measurements were underestimated on 3D-TOF images although there was still a significant correlation (R(2) = 0.72, p < 0.05). Comparison of TOF and BB examinations to the composite reference using the Wilcoxon signed-rank test showed significant improvement in the demonstration of the aneurysm to parent/branch vessels and the morphology/size of the aneurysm neck, particularly in the setting of local haematoma or slow flow (p < 0.001). We propose the addition of the BB sequence as a useful adjunct to 3D-TOF imaging particularly when detailed aneurysm morphology is required or there is thrombus in subarachnoid space.

Glandular function in Sjögren syndrome: assessment with dynamic contrast-enhanced MR imaging and tracer kinetic modeling--initial experience.

PURPOSE: To prospectively use dynamic contrast material-enhanced magnetic resonance (MR) imaging and a tracer kinetic model to compare parotid gland microvascular characteristics in patients who have Sjögren syndrome (SS) with those in healthy volunteers. MATERIALS AND METHODS: The local research ethics committee approved the study, and written informed consent was obtained from all participants. Twenty-one patients (19 women, two men; age range, 31-73 years) with a diagnosis of SS and 11 healthy volunteers (10 women, one man; age range, 41-68 years) underwent three-dimensional T1-weighted dynamic contrast-enhanced MR imaging of the parotid gland at 1.5 T. A voxel-wise tracer kinetic model and a model-free analysis were applied to the dynamic MR data. Parameter medians and standard deviations were computed to summarize gland microvascular characteristics and gland heterogeneity, respectively. Differences were investigated by using multivariate analysis of variance, t, or U tests. Further investigation was performed by using linear discriminant and receiver operating characteristic analyses. RESULTS: Compared with the healthy volunteers, the patients with SS had highly significant elevations (P << .001) in the model-free parameter initial area under the curve and in tracer kinetic model parameters, including transcapillary contrast agent transfer constant (P < .001) and extracellular extravascular volume (P < .001). Gland heterogeneity was significantly greater (P < .001) in the patients with SS. Parameter medians and standard deviations enabled excellent differentiation (areas under receiver operating characteristic curve, 0.96 and 1.00, respectively) between the patients with SS and the healthy volunteers. CONCLUSION: Dynamic contrast-enhanced MR imaging has the potential to be used in clinical settings to quantify microvascular function in SS and to differentiate between patients with and those without SS.