Quantitative evaluation of Ki-67 labeling index in glioma with transfer constant derived from dynamic contrast-enhanced MRI

Objective To study the value of transfer constant(Ktrans)derived from dynamic contrast-enhanced MRI (DCE-MRI) for quantitative evaluation of Ki-67 labeling index (Ki-67 LI) in glioma. Methods Twenty patients with glioma who underwent DCE-MRI and operation were retrospectively reviewed. The Ktrans value and Ki-67 LI were acquired and correlated using the Spearman correlation test. Also, the Ktrans values were compared between high(larger than 10%)and low(no more than 10%)Ki-67 LI group with Mann-Whitney U test, receiver operating characteristic curves was performed to evaluate the diagnostic value. Results The Ktrans value(0.016 5 to 0.804 8, median 0.125 2)was significantly associated with Ki-67 LI(5% to 50%, median 20%)(r=0.721, P<0.001), and the Ktrans value was significantly higher in high Ki-67 group(0.081 0 to 0.804 8, median 0.181 0)than that in low Ki-67 LI group(0.016 5 to 0.145 6, median 0.069 7)(Z=-3.209, P=0.001). The most predictive Ktrans value differentiated high Ki-67 LI and low Ki-67 LI with an area under the curve(AUC) of 0.945 at a sensitivity of 92.3% and specificity of 85.7%. Conclusion Ktrans value could be used for quantitative evaluation of Ki-67 LI in glioma. Key words: Glioma; Magnetic resonance imaging; Ki-67 antigen