[Value of readout-segmented echo-planar diffusion imaging on 3.0 T MRI for predicting the early efficacy of concurrent radiochemotherapy of advanced stage nasopharyngeal carcinoma patients]

Objective: To discuss the value of RESOLVE for predicting early therapeutic effect of concourrent radiochemotherapy in advanced stage nasopharngeal carcinoma patients. Methods: Sixty-eight patients with nasopharyngeal carcinoma were confirmed by pathology in Henan Cancer Hospital from June 2014 to January 2016.All patients underwent RESLOVE(b value=800 s/mm(2)) with a 3.0 T MRI scanner.The ADC value and the area of the tumor was measured before treatment and 2 weeks after treatment independently performed by two radiologists with 5 years experiences and the agreement evaluation was performed using ANOVA analysis.The correlation among pretreatment ADC value, pathology type, gender, tumor area and the tumor regression rate were analyzed using Spearman rank correlation test.The difference between pretreatment ADC value was compared in CR group and non-CR group by independent sample t test.ROC curve was drawn and the maximum Youden index value was the cutoff calculating the ADC value and predicting the sensitivity, specificity and area under the curve. Results: (1)The agreement between 2 radiologist was excellent. The ICC values of the ADC and the area of the tumor before treatment and the area of the tumor after treatment were 0.89, 0.92 and 0.95, respectively. (2)The pretreatment ADC values of the CR group and the non-CR group were (0.877±0.103)×10(-3) mm(2)/s and (0.779±0.078)×10(-3) mm(2)/s, respectively. There was statistical difference t value=2.874, P value=0.005.(3)ROC curve showed that the sensitivity and specificity of the pretreatment ADC value in predicting CR was 85.2% and 71.0%, with the cut-off value of 0.792×10(-3) mm(2)/s, and the area under curve was 0.778.(4)There was apparently correlation beween the pretreatment ADC value and the tumor regression rate(r=0.333, P=0.006). There was no correlation among pretreatment ADC value, pathology type, gender and tumor area (P>0.05). Conclusion: There is important value using the pretreatment ADC value measured by RESOLVE for predicting the early effect of concurrent radiochemotherapy in advanced stage nasopharngeal carcinoma patients.