Enhancing Diagnostic Accuracy by Utilizing Regional Cerebral Blood Flow (rCBF) as a Value-Added Variable to Dynamic Contrast-Enhanced Perfusion-Weighted Imaging for Differentiating Radionecrosis From Recurrent Brain Tumour.

Purpose To enhance diagnostic accuracy by incorporating relative cerebral blood flow (rCBF) as an additional parameter to dynamic susceptibility contrast perfusion-weighted imaging (DSC-PWI) variables, thereby enabling the differentiation between radionecrosis and recurrent brain tumours. Materials and methods This study involved 54 patients who had previously undergone treatment for primary cerebral tumours. All participants received radiotherapy and underwent both conventional MRI and DSC-PWI. MRI scans were performed using a 1.5 T closed MRI scanner (MAGNETOM Aera, Siemens Healthineers, Erlangen, Germany), equipped with a 16-channel Head/Neck coil for image acquisition. Several perfusion variables were calculated from DSC-PWI, including rCBF, relative cerebral blood volume (rCBV), relative peak height (rPH), and relative percentage of signal intensity recovery (rPSR). Statistical analyses included ANOVA and receiver operating characteristic (ROC) curve analysis, with histopathological findings used as the reference standard for diagnostic correlation. Results A total of 38 patients (38/54, 70.4%) were diagnosed with tumour recurrence (TR), while 16 patients (16/54, 29.6%) were diagnosed with radionecrosis. The values of rCBF, rCBV, rPSR, and rPH were significantly higher ( < 0.05) in recurrent tumours compared to radionecrosis lesions. At a cutoff value of ≥1.42, rCBF demonstrated a sensitivity of 0.95 and a specificity of 0.94. The area under the curve (AUC) for rCBF peaked at approximately 0.97, surpassing other parameters: rCBV (0.948), rPSR (0.069), and rPH (0.871). Conclusion DSC-PWI is a diagnostic tool that helps differentiate between TR and radionecrosis using several variables, the most important of which is rCBF.