Prognostic value of relative enhancement metrics based on preconcurrent chemoradiotherapy magnetic resonance imaging (pre-CCRT MRI) volumetric segmentation in glioblastoma.

Aim: The purpose of this study was to identify the impact of relative contrast enhancement (rCE), based on volumetric segmentation from preconcurrent chemoradiotherapy magnetic resonance imaging (pre-CCRT MRI), in predicting tumour progression and unfavourable survival in glioblastoma (GBM) patients.

Materials And Methods: Seventy-seven GBM patients underwent conventional MRI before and after radiochemotherapy. Residual cavity wall enhancement was segmented using Image J software, and rCE was calculated. Clinical and imaging variables were compared between shorter and longer overall survival (OS) groups. Multivariable logistic regression was performed to identify the significant predictors of survival outcomes. Diagnostic performance was evaluated using receiver operating characteristic curve (ROC) analysis. Survival outcomes based on rCE were compared using Kaplan-Meier analysis.

Results: Older age, nodular and thick linear enhancement, larger orthogonal lesion size on fluid-attenuated inversion recovery (FLAIR) and contrast-enhanced T1-weighted imaging, and higher rCE (≥1.265) were significant predictors of tumour progression. Multivariate analysis showed that higher rCE was an independent predictor of shorter progression-free survival (HR = 4.829). Additionally, older age and higher rCE were independent predictors of shorter OS (HR = 1.048 and 3.792, respectively). A combined model incorporating rCE with clinical and conventional MR variables achieved an area under the ROC curve (AUC) of 0.845 and an accuracy of 79.6% in predicting shorter OS.

Conclusion: Pre-CCRT volumetric segmentation-based rCE may improve the prediction of GBM progression and survival, and holds potential as a practical imaging biomarker to guide personalised precision treatment.