Residual pattern of the hyperintense area on T2-weighted magnetic resonance imaging after initial treatment predicts the pattern and location of recurrence in patients with newly diagnosed glioblastoma

Abstract

Purpose: This study aimed to investigate the clinical significance of residual hyperintensity on T2-weighted magnetic resonance imaging in patients with glioblastoma (GB) without enhanced lesions at the end of initial treatment with debulking surgery and concomitant radiotherapy and temozolomide. Methods: Among 185 GB cases, 80 cases without enhanced lesions at the end of initial treatment and without factors modifying the distribution of residual hyperintense area or pattern of recurrence were included. We retrospectively reviewed the relationship of residual hyperintense area after initial treatment with progression-free survival (PFS), overall survival (OS), and pattern of recurrence. Results: In these 80 cases, the median PFS and OS were 12.0 and 37.5 months, respectively. At the end of initial treatment, 53 (66.3%) cases had residual hyperintense lesions (T2 residual group, T2R), whereas 27 (33.8%) showed no hyperintensity (T2 vanished group, T2V). Based on univariate and multivariate analyses, the residual hyperintense area after initial treatment was not a prognostic factor for PFS or OS. Distant recurrences occurred more frequently in the T2V group than in the T2R group (47.6% vs. 12.8%). In the T2R group, the recurrence site coincided with the residual hyperintense area in 32 (80.0%) of 40 recurrences. Conclusion: In GB cases without enhanced lesions at the end of initial treatment, the complete disappearance of the residual hyperintense area after initial treatment does not indicate a favorable outcome. Additionally, distant recurrences should be considered in T2V group and local recurrences should be considered in T2R group.