Arterial Spin-Labeling and DSC Perfusion Metrics Improve Agreement in Neuroradiologists’ Clinical Interpretations of Posttreatment High-Grade Glioma Surveillance MR Imaging—An Institutional Experience

Abstract

BACKGROUND AND PURPOSE: MR perfusion has shown value in the evaluation of posttreatment high-grade gliomas, but few studies have shown its impact on the consistency and confidence of neuroradiologists' interpretation in routine clinical practice. We evaluated the impact of adding MR perfusion metrics to conventional contrast-enhanced MR imaging in posttreatment high-grade glioma surveillance imaging. MATERIALS AND METHODS:This retrospective study included 45 adults with high-grade gliomas who had posttreatment perfusion MR imaging. Four neuroradiologists assigned Brain Tumor Reporting and Data System scores for each examination on the basis of the interpretation of contrast-enhanced MR imaging and then after the addition of arterial spin-labeling-CBF, DSC-relative CBV, and DSC-fractional tumor burden. Interrater agreement and rater agreement with a multidisciplinary consensus group were assessed with k statistics. Raters used a 5-point Likert scale to report confidence scores. The frequency of clinically meaningful score changes resulting from the addition of each perfusion metric was determined. RESULTS:Interrater agreement was moderate for contrast-enhanced MR imaging alone (k ¼ 0.63) and higher with perfusion metrics (arterial spin-labeling-CBF, k ¼ 0.67; DSC-relative CBV, k ¼ 0.66; DSC-fractional tumor burden, k ¼ 0.70). Agreement between raters and consensus was highest with DSC-fractional tumor burden (k ¼ 0.66-0.80). Confidence scores were highest with DSCfractional tumor burden. Across all raters, the addition of perfusion resulted in clinically meaningful interpretation changes in 2%-20% of patients compared with contrast-enhanced MR imaging alone. CONCLUSIONS:Adding perfusion to contrast-enhanced MR imaging improved interrater agreement, rater agreement with consensus, and rater confidence in the interpretation of posttreatment high-grade glioma MR imaging, with the highest agreement and confidence scores seen with DSC-fractional tumor burden. Perfusion MR imaging also resulted in interpretation changes that could change therapeutic management in up to 20% of patients.ABBREVIATIONS: ASL ¼ arterial spin-labeling; BT-RADS ¼ Brain Tumor Reporting and Data System; CE ¼ contrast-enhanced; CRT ¼ chemoradiotherapy; FTB ¼ fractional tumor burden; GBM ¼ glioblastoma; HGG ¼ high-grade glioma; IRA ¼ interrater agreement; rCBV ¼ relative CBV S urveillance MR imaging following surgery and chemoradiotherapy (CRT) is integral to the care of patients with highgrade gliomas (HGGs). In the Response Assessment in Neuro-Oncology criteria, the assessment of tumor status is based on