Peritumoral edema on MRI at initial diagnosis: an independent prognostic factor for glioblastoma?

Peritumoral brain edema in glioblastoma patients is a frequently encountered phenomenon that strongly contributes to neurological signs and symptoms. The role of peritumoral edema as a prognostic factor is controversial. This multi-centre clinical retrospective study included 110 patients with histologically proven glioblastoma. The prognostic impact on overall survival of pre-treatment peritumoral edema detected on MRI-scans was evaluated. All patients had preoperative MRI, surgery, histology, and received standard treatment regimens. Edema on MRI-scans was classified as minor (< 1 cm), and major (> 1 cm). Our results confirm that peritumoral edema on preoperative MRI is an independent prognostic factor in addition to postoperative Karnofsky performance score (KPS), age, and type of tumor resection. Patients with major edema had significant shorter overall survival compared to patients with minor edema. This easily applicable early radiological characterization may contribute to a more subgroup oriented treatment in glioblastoma patients for future trials, as well as in clinical routine.