gms | German Medical Science

Objective: FLAIR-hyperintense lesions are known to have prognostic significance in Glioblastoma multiforme (GBM). The dynamics of FLAIR signals in the peritumoral area can be helpful to predict the tumor recurrence. The dynamic of FLAIR hyperintensity during the tumor treatment seems to have a complex dynamic, which is still not completely understood. In this study, we explored the patterns of FLAIR hyperintensity and its prognostic meaning in GBM patients from a single-center tumor registry.

Methods: We reviewed the data of 242 patients (94 female) treated for GBM WHO IV at our institution between 2010 and 2017. Patient and tumor characteristics, operative and adjuvant therapies, as well as progression free survival and overall survival were recorded. Volumetric analysis was performed with Brainlab Software. Statistical analysis was done on the Statistica software.

Results: The overall survival of our patient cohort was of 15,2 months, while the progression-free survival was of 7,5 months. The majority of patients received concomitant radiochemotherapy (Stupp protocol) as a first-line treatment. The mean tumor volume was of 43,91 cm³ and the mean FLAIR volume of 102,43 cm³. We identified several typical tumor patterns: single FLAIR hyperintensity area over the tumor; large peritumoral hyperintensity area with several smaller lesions in the tumor periphery; main FLAIR area and several smaller distant solitary FLAIR lesions; generalized small FLAIR islands; FLAIR hyperintensity infiltrating the corpus callosum, the capsula interna and the brainstem. Multifocal FLAIR lesions were seen in 82 patients (50,9%). There was no significant correlation with age, sex, or molecular markers (IDH1 mutation, MGMT methylation status). FLAIR infiltration of the corpus callosum in initial imaging was associated with a poor prognosis (OS 12,1 months vs. 26,1 months, p=0,011) as well as with a larger tumor size (48,3 cm³ vs. 25,75 cm³). In several cases, distant tumor recurrence was found in areas without contrast-enhancing lesions in the initial imaging.

Conclusion: Specific FLAIR patterns could have a prognostic meaning for GBM patients. Multifocal FLAIR is seen in about 50% of GBM patients and is not influenced by patient-related or molecular factors. Corpus callosum infiltration on initial imaging is associated with poor prognosis. Future studies should address FLAIR dynamics predictive for tumor recurrence before the development of a contrast-enhancing lesion.