Anzeige
Erschienen in:
17.11.2016 | Magnetic Resonance
Prognostic relevance of gemistocytic grade II astrocytoma: gemistocytic component and MR imaging features compared to non-gemistocytic grade II astrocytoma
Erschienen in: European Radiology | Ausgabe 7/2017
Einloggen, um Zugang zu erhaltenAbstract
Objectives
To determine if gemistocytic grade II astrocytoma (GemA) and its MR imaging characteristics are associated with a shorter time-to-progression (TTP) compared with non-gemistocytic grade II astrocytoma (non-GemA).
Materials and methods
We enrolled 78 patients who were followed up more than 5 years (29 pathologically proven GemA and 49 non-GemA) during a 10-year period. Contrast-enhanced T1-weighted, diffusion-weighted imaging (DWI), dynamic susceptibility contrast (DSC), and MR spectroscopy (MRS) and clinical data were retrospectively reviewed. Clinical and MR imaging features were analyzed as possible prognostic factors of high-grade transformation, and multivariate analysis of TTP was performed using Cox proportional modeling.
Results
GemA showed more frequent high-grade features than non-GemA, including diffusion restriction (P < .001), increased choline/creatine (P = .02), and increased choline/NAA ratio (P = .015). Patients with GemA had a significantly shorter median TTP (53.1 vs 68 months; P < .001). A gemistocytic histopathology (hazard ratio = 3.42; P = .015) and low ADC (hazard ratio = 3.61; P = .001) were independently associated with a shorter TTP.
Conclusions
GemA can present with MR imaging findings mimicking high-grade glioma at initial diagnosis and transforms to high-grade disease earlier than non-GemA. Low ADC on DWI might be useful in stratifying the risk of progression in patients with grade II astrocytoma.
Key Points
• Gemistocytic grade II astrocytoma (GemA) showed more frequent high-grade features than non-GemA.
• Patients with GemA had a significantly shorter median TTP than non-GemA.
• Gemistocytic histopathology and low ADC were independently associated with shorter TTP.