Differentiation Between True Tumor Progression of Glioblastoma and Pseudoprogression Using Diffusion-Weighted Imaging and Perfusion-Weighted Imaging: Systematic Review and Meta-analysis

BACKGROUND: On brain magnetic resonance imaging, both diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) are used to evaluate cerebral tumors. The purpose of this meta-analysis was to evaluate and compare the diagnostic performance of DWI and PWI in differentiating between pseudoprogression and true tumor progression of glioblastoma.METHODS: We performed a systematic review of the PubMed database from January 2000 to December 2019 for relevant studies. After application of specific inclusion and exclusion criteria, the eligible articles were evaluated for methodologic quality and risk of bias using the updated Quality Assessment of Diagnostic Accuracy (QUADAS-2) tool. From the published study results, the pooled sensitivity, pooled specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio and their corresponding confidence intervals (% CI), and the area under the curve, were calculated individually for DWI and PWI.RESULTS: The meta-analysis included 24 studies, with a total of 900 patients. DWI was found to be slightly superior in terms of sensitivity and specificity, 0.88 (% CI 0.83-0.92) and 0.85 (% CI 0.78-0.91), respectively, compared with the respective values of PWI, 0.85 (% CI 0.81-0.89) and 0.79 (% CI 0.74-0.84). On comparison of the overall diagnostic accuracy of the MRI modalities using their respective area under the curve values (0.9156 for DWI, 0.9072 for PWI), no significant difference was demonstrated between the 2.CONCLUSIONS: Both DWI and PWI provided optimal diagnostic performance in differentiating pseudoprogression from true tumor progression in cerebral glioblastoma, and neither technique proved to be superior.