Prognostic paradox: brain damage around the glioblastoma resection cavity

Hyperintense lesions around the resection cavity on magnetic resonance diffusion-weighted imaging (MR-DWI) frequently appear after brain tumor surgery due to the damage of surrounding brain. The putative connec- tion between the lesion and the prognosis for patients with glioblastoma (GBM) was explored. This retrospective study reviewed consecutive sixty-one patients with newly diagnosed GBM. Postoperative MRI was performed within 2 weeks after the initial surgery. We classified the cases into two groups depending on whether DWI hyperintense lesions were observed or not (DWI(?) group and DWI(-) group). Progression-free survival (PFS) and overall sur- vival (OS) were compared between the two groups. Forty- two patients were identified. The various extents of hyperintense lesions around the resection cavity were observed in 28/42 (66.7 %) cases. In the DWI(?) and DWI(-) groups, median PFS was 10.0 (95 % confidence interval (CI) 8.4-11.5) and 6.7 (95 % CI 4.9-8.5) months, respectively (p = 0.042), and median OS was 18.0 (95 % CI 12.2-23.8) and 17.0 (95 % CI 15.7-18.3) months, respectively (p = 0.254). On multivariate analysis, the presence of DWI hyperintense lesion was more likely to be an independent predictor for 6-month PFS (p = 0.019; HR, 0.038; 95 % CI 0.002-0.582). Tumor recurrence appeared outside the former DWI hyperintense lesion. Hyperintense lesions surrounding the resected GBM on MR-DWI might be a favorable prognostic factor in patients with GBM.