Value of Amide Proton Transfer-Weighted Imaging and T2 Mapping for Predicting Microsatellite Instability in Endometrial Adenocarcinoma.

Objective To identify the feasibility of amide proton transfer-weighted imaging(APTw)and T2 mapping parameters in assessing microsatellite instability(MSI)in endometrial adenocarcinoma(EA). Methods Patients with clinically suspected endometrial cancer were prospectively enrolled and underwent MRI before the operation,which mainly included APTw and T2 mapping.Two radiologists independently performed regions of interest and measured the quantitative parameters.The intraclass correlation coefficients were used to assess the interobserver agreement,the independent samples t-test and Mann-Whitney U test were applied to compare quantitative variables between the MSI and microsatellite stable(MSS)groups,the receiver operator characteristic(ROC)curve was conducted to evaluate the predictive performances of different parameters,the Delong test was implemented to compare the area under the curve(AUC)between single parameters and their combination. Results Twenty-one patients in the MSI group and 37 patients in the MSS group were finally enrolled in this study.The results showed excellent observer agreements between two observers in assessing MRI parameters.APTw values[(2.72±0.52)% vs.(2.08±0.39)%,P<0.001]in the MSI group were significantly higher than those in the MSS group, T2 values [92.25(90.82, 99.91) ms vs.101.80(96.15, 112.13)ms, P<0.001]were significantly lower in the MSI group than those in the MSS group.The ROC curves showed that the AUCs of APTw and T2 values were 0.821 and 0.793,respectively,and no significant difference was observed between the two sequences(P＞0.05).The combination of APTw and T2 mapping yielded the highest AUC of 0.897,which was significantly higher than APTw and T2 mapping alone(both P＜0.05). Conclusion APTw and T2 mapping were valuable in assessing the MSI of EA,and the combination of the two parameters showed a higher diagnostic efficacy,thus providing an efficient basis for the selection of preoperative therapeutic modalities for the patients.