Preoperative tumor cerebral blood flow measured by arterial spin labeling predicts enhancing tumor volume progression in gliomas: a single-center retrospective study

Background Arterial spin labeling (ASL) enables non-invasive quantification of cerebral blood flow (CBF). The preoperative prognostic value of tumor-specific CBF for subsequent enhancing tumor (ET) volume progression in gliomas remains poorly characterized. Methods In this study 60 glioma patients (predominantly glioblastoma, WHO grade 4) with preoperative 3T ASL MRI and paired follow-up structural MRI were analyzed. Tumor CBF, surrounding CBF, and whole-brain CBF were quantified from the segmented regions of interest. ET and surrounding non-enhancing FLAIR-hyperintense (SNFH) volume changes were calculated and correlated with preoperative perfusion data. Spearman correlations, Kruskal-Wallis tests, multivariable linear and logistic regression, and ROC analyses were performed. Results Higher preoperative tumor CBF strongly predicted net ET volume increase (Spearman r = 0.531, p < 0.0001) and ET progression category (Kruskal-Wallis p = 0.0005). Mean tumor CBF was 147.7 ml/100 g/min in ET-increased versus 124.4 ml/100 g/min in unchanged and 115.8 ml/100 g/min in decreased cases. Tumor CBF remained an independent predictor after adjusting for age, scan interval, and MGMT status (linear regression p = 0.002; logistic regression OR = 2.02 per ml/100 g/min, p = 0.001). Associations with SNFH volume changes were weak and non-significant. Surrounding CBF closely matched whole-brain CBF (Pearson r ≈ 1.00). Tumor CBF alone yielded 5-fold CV AUC = 0.805 for predicting ET progression; the combined model (tumor CBF + ET volume) improved to AUC = 0.858. Conclusion Preoperative ASL-derived tumor CBF appears to be an independent non-contrast imaging biomarker for early enhancing tumor progression risk in gliomas.