Arterial spin-labeling in children with brain tumor : A meta-analysis

BACKGROUND: The value of arterial spin-labeling in a pediatric population has not been assessed in a meta-analysis. PURPOSE: Our aim was to assess the diagnostic accuracy of arterial spin-labeling- derived cerebral blood flow to discriminate low- and high-grade tumors. DATA SOURCES: MEDLINE, EMBASE, the Web of Science Core Collection, and the Cochrane Library were used. STUDY SELECTION: Pediatric patients with arterial spin-labeling MR imaging with verified neuropathologic diagnoses were included. DATA ANALYSIS: Relative CBF and absolute CBF and tumor grade were extracted, including sequence-specific information. Mean differences in CBF between low- and high-grade tumors were calculated. Study quality was assessed. DATA SYNTHESIS: Data were aggregated using the bivariate summary receiver operating characteristic curve model. Heterogeneity was explored with meta-regression and subgroup analyses. The study protocol was published at PROSPERO (CRD42017075055). Eight studies encompassing 286 pediatric patients were included. The mean differences in absolute CBF were 29.62 mL/min/100 g (95% CI, 10.43- 48.82 mL/min/100 g), I2 74, P .002, and 1.34 mL/min/100 g (95% CI, 0.95-1.74 mL/min/100 g), P .001, I2 38 for relative CBF. Pooled sensitivity for relative CBF ranged from 0.75 to 0.90, and specificity, from 0.77 to 0.92 with an area under curve 0.92. Meta-regression showed no moderating effect of sequence parameters TE, TR, acquisition time, or ROI method. LIMITATIONS: Included tumor types, analysis method, and original data varied among included studies. CONCLUSIONS: Arterial spin-labeling- derived CBF measures showed high diagnostic accuracy for discriminating low- and high-grade tumors in pediatric patients with brain tumors. The relative CBF showed less variation among studies than the absolute CBF