Distinguishing Edema from Tumor Infiltration in High-Grade Glioma Patients: Initial Insights from quantitative MRI using Relaxometry

Abstract Introduction: The differentiation between edema and tumor infiltration in high-grade gliomas is fundamental for surgical planning. However, this distinction is challenging using conventional magnetic resonance imaging (MRI). Relaxometry is a new technique for quantitative diagnosis using MRI, currently under assessment for some neurological disorders. Methods: In this study, we report our initial experience using T2 multiecho relaxometry to differentiate perilesional edema from tumor infiltration in patients with high-grade gliomas. In order to have values for a comparative analysis, we assumed T2-hyperintensity surrounding the enhancing tumor represented vasogenic edema on meningiomas or metastasis, while it could be vasogenic edema or tumor infiltration on high-grade gliomas. Results: Twenty patients with high-grade gliomas and 10 patients with metastases or meningiomas were included. Images were analyzed using Relaxo software. Mean T2 value in regions of hypersignal for the metastasis group was 196.8, compared to 407.3 in high-grade gliomas. Discussion: Difference was statistically significant ( p <0.05). Our results suggest that the LNI relaxo software could be a helpful tool to differentiate edema and tumor infiltration in patients with high-grade gliomas, allowing for a more efficient preoperative planning and postoperative assessment of tumor infiltration resection rate.