NIMG-17. PREDICTIVE VALUE OF THE BRAIN TUMOR REPORTING AND DATA SYSTEM SCORE (BT-RADS) ON FUNCTIONAL OUTCOMES AND PROGRESSION-FREE SURVIVAL IN GLIOBLASTOMA PATIENTS

Abstract The Brain Tumor Reporting and Data System Score (BT-RADS) is a novel eight-point classification system that standardizes magnetic resonance imaging (MRI) reporting in glioblastoma (GB) patients. While previous studies have demonstrated BT-RADS predictive value in the prognosis and overall survival of high-grade glioma patients, its association with functional outcomes and progression-free survival (PFS) in GB patients is unclear. We aim to evaluate the BT-RADS predictive value on functional outcomes assessed through the Karnofsky Performance Scale (KPS) at one year post-diagnosis and on PFS. BT-RADS from MRI ~3 months post-diagnosis after chemo-radiation therapy (BT-RADS_1), and ~6 months post-diagnosis after the 6-month maintenance temozolomide (TMZ) cycle (BT-RADS_2) were analyzed. BT-RADS was classified as low (BT-RADS score 0-3a) and high (BT-RADS score 3b-4). In a univariate logistic regression analysis, BT-RADS_1 was a significant predictor (p=0.04) in discriminating an unfavorable KPS from a favorable one. In a multivariate logistic regression, in which the best model fit was the model containing BT-RADS_1 and MGMT tumor status (model p value=0.03), the ROC analyses indicate that BT-RADS_1 is not better than chance in differentiating an unfavorable KPS from a favorable one (model AUC=0.65; 95% CI=0.55, 0.76). The discriminatory ability of BT-RADS scores alone in predicting KPS outcomes was modest, as indicated by the AUC. This underscores the need for larger sample sizes. In a final model of BTRADS_1 and BT-RADS_2, accounting for MGMT tumor status, the risk of tumor progression was 50% lower (p value=0.003) with a low BT-RADS (0-3a) in the BT-RADS _1 group and 38% lower (p value=0.03) with a low BT-RADS (0-3a) in the BT-RADS_2 group. Considering the above-discussed findings, BT-RADS may represent a new tool in the clinical management of glioblastoma patients by informing on disease progression, prognosis, and quality of life.