Objective: This study determined the diagnostic performance of fluid-attenuated inversion recovery (FLAIR) signal intensity (SI) in discriminating between glioblastoma (GBM) and solitary brain metastasis (SBM).
Patients and methods: We recruited 40 patients with a histologically confirmed diagnosis of GBM or SBM who underwent conventional 3 Tesla magnetic resonance imaging before surgery or biopsy between August 2020 and January 2022. Three regions of interest were placed to assess FLAIR SI: the enhancing region (eFLAIR), the peritumoral region (pFLAIR), and the contralateral normal white matter (nFLAIR). The diagnostic performance of significantly different parameters between the two tumor entities was analyzed by receiver operating characteristic (ROC) curve analysis.
Results: The pFLAIR SI was significantly lower in GBM than in SBM (p < 0.05). The eFLAIR SI and the SI ratio eFLAIR and nFLAIR (e/nFLAIR) were significantly higher in GBM than in SBM (p < 0.05). On ROC curve analysis, the e/nFLAIR ratio provided the highest area under the curve value of 81%, with a sensitivity of 80.8% and a specificity of 85.7%, for distinguishing between the two tumor types.
Conclusions: The eFLAIR, pFLAIR, and e/nFLAIR parameters are useful for differentiating between GBM and SBM.