Differentiation between radiation-induced brain injury and glioma recurrence using 3D pCASL and dynamic susceptibility contrast-enhanced perfusion-weighted imaging

Purpose: This study was performed to validate the efficacy of three-dimensional pseudocontinuous arterial spin labeling (pCASL) compared with dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI) in distinguishing radiation-induced brain injury from glioma recurrence in patients with glioma. Methods: Both 3D pCASL and DSC-PWI were performed using a 3.0 Tesla scanner in 69 patients with previously resected and irradiated glioma who displayed newly developed abnormal contrast-enhanced lesions. The included patients were classified into a radiation-induced brain injury group (n = 34) and a glioma recurrence group (n = 35) based on subsequent pathologic analysis or clinical-radiological follow-up. Lesion perfusion parameter values (CBF and nCBF on pCASL, nrCBV and nrCBF on DSC-PWI) were measured and compared between the two groups using Student's t test. Pearson correlation analysis was performed to evaluate the correlation between pCASL (CBF and nCBF) and DSC-PWI (nrCBV and nrCBF) values in the contrast-enhanced lesions and in the perifocal edema regions. Results: For the contrast-enhanced lesions, the CBF, nCBF, nrCBV, and nrCBF (29.46 +/- 15.08 ml/100 g/min, 1.11 +/- 0.50, 1.39 +/- 1.15, and 1.30 +/- 0.74) in the radiation-induced brain injury group were significantly lower than those (64.52 +/- 33.92 ml/100 g/min, 2.73 +/- 1.71, 3.39 +/- 2.12, and 3.20 +/- 1.95) in the glioma recurrence group (P < 0.001). The CBF and nCBF demonstrated strong correlation with nrCBV and nrCBF in the contrast-enhanced lesions. Conclusion: Radiation-induced brain injury and glioma recurrence can be reliably distinguished using both 3D pCASL and DSC-PWI. Contrast-free 3D pCASL is a suitable alternative to DSC-PWI for longterm follow-up in glioma patients with postoperative radiotherapy. (C) 2018 Elsevier B. V. All rights reserved. Radiotherapy and Oncology