[The value of DCE-MRI combined with spectral CT in the short-term efficacy of concurrent chemoradiotherapy for nasopharyngeal carcinoma]

Objective:To explore the value of spectral CT parameters combined with dynamic contrast enhanced magnetic resonance imaging（DCE-MRI） parameters in the short-term efficacy of concurrent chemoradiotherapy for nasopharyngeal carcinoma. Methods: A total of 110 cases with nasopharyngeal carcinoma Ⅲ-Ⅳ staging who received synchronous radiotherapy and chemotherapy at our Hospital from October 2022 to October 2024 were regarded as the study subjects. Complying with the evaluation results after radiotherapy and chemotherapy, they were divided into a complete remission（CR） group of 53 cases and a non CR group of 57 cases. All patients underwent DCE-MRI and energy dispersive CT scans to obtain parameters, such as iodine concentration（IC）, volume transfer constant（Ktrans）, slope of spectral HU curve（λHU）, rate constant（Kep）, and normalized iodine concentration（NIC）. Logistic regression analysis was used to screen for influencing factors. ROC curve was used to analyze the evaluation value of various parameters. In addition, Z-test was used to compare area under the curve（AUC）. Results:The proportion of retropharyngeal lymph node metastasis and λHUvalue in the non CR group were higher than those in the CR group, while Ktrans, Kep, IC value, and NIC value were lower than those in the CR group（P<0.05）. Retropharyngeal lymph node metastasis, Ktrans, Kep, IC value, λHUvalue, and NIC value were all influencing factors（P<0.05）. The AUC of individual prediction of Ktrans, Kep, IC value, λHUvalue, and NIC value was 0.817, 0.800, 0.785, 0.783, and 0.835, respectively. The AUC of the combination of DCE-MRI parameters, the combination of spectral CT parameters, and the combination of the five parameters were 0.874, 0.900, and 0.980, respectively, the AUC of the combination of the five parameters was significantly higher than the AUC of each indicator alone, the AUC of the combination of DCE-MRI parameters, and the AUC of the combination of spectral CT parameters（P<0.05）. Conclusion:The DCE-MRI, and spectral CT parameters （Ktrans, Kep, IC value, λHUvalue, and NIC value）can be used to evaluate concurrent radiotherapy and chemotherapy short-term efficacy for nasopharyngeal carcinoma. And the combination of various parameters can greatly improve the predictive value of efficacy, which has important clinical application value.