Assement Of Chemoradiotherapy Efficacy In Patients With Nasopharyngeal Carcinoma By MRI

Part I Value of Magnetic Resonance Diffusion-Weighted Imaging for the Prediction of chemoradiotheray efficacy in Nasopharyngeal CarcinomaPurpose: To prospectively evaluate the efficacy of pre-treatment DWI and ADC for treatment response to chemoradiotherapy(CRT) of Nasopharyngeal CarcinomaMethods: 46 patients with confirmed NPC by biopsy pathology underwent MRI and DWI( b value=0,800 s/mm2) before concurrent chemoradiation. Calculate the mean, maximum and minimum area of the ADC values. Reexamined those patients with MRI during treatment(receiving dose of 56Gy) and measure the tumor regression rate respectively. Classified patients into three groups as complete resoponse, partial response and stable disease, based on RECIST1.1. Spearman correlation analysis was examed between the pre-treatment mean, maximum and minimum area of the ADC values and regression rate,respectively. The predictive value of the ADC was examed with ROC curve.Result: The study group was composed of 37 patients, 31 male and 6 female. The tumor stage was as 9 cases of T2, 12 cases of T3, 16 cases of T4. There was a significant negative correlation between tumor regression rate and both mean(r=-0.277, P<0.05) and maximum(r=-0.642, P<0.05) area of ADC values.There is no relationship between minimum area of the ADC values and tumor regression rate. AUC= 0.833 with a sensitivity of 85.7% and specificity of 86.7% was observed in differentiating responders(n = 7) from nonresponders(n = 30) when ADC values <1.247×10-3 mm/s2. When ADC values>1.394×10-3 mm/s2,,we observedAUC=0.717 with sensitivity and specificity is 57.1% and 83.3% respectively in differentiating resistant(n = 7) from others(n = 30).Conclusion: DWI and ADC value before treatment were capable to predict early treatment efficacy during concurrent chemoradiation in nasopharyngeal carcinoma, which has potential to be helpful in individualized therapy.Part II Value of Dynamic contrast-enhancement MRI for the Prediction of chemoradiotheray efficacy in Nasopharyngeal CarcinomaPurpose: To prospectively evaluate the efficacy of pre-treatment DCE-MRI for treatment response to chemoradiotherapy(CRT) of Nasopharyngeal CarcinomaMethods: 46 patients with confirmed NPC by biopsy pathology underwent MRI and DCE-MRI before concurrent chemoradiation. Calculate the mean, maximum and minimum area of the semiquantitative parameters. Reexamined those patients with MRI during treatment(receiving dose of 56Gy) and measure the tumor regression rate respectively. Classified patients into responders and nonresponders, based on RECIST 1.1. Spearman correlation analysis was examed between both pre-treatment mean, maximum and minimum area of the semiquantitative parameters and regression rate,respectively. ROC analyses were used to determine the best model to discriminate responders from nonresponders.Result: Among all the parameters, there was a significant negative correlation between tumor regression rate and TTP(-0.716~-0.853, P<0.05). Positive correlation between tumor regression rate and minimum area of Maxenh(r=0.39, P<0.05). Both mean and maximum wash-in-rate and mean and minimum wash-out-rate have significant correlation between tumor regression rate(0.386~0.46, 0.404~0.471, P<0.05). there was a dignificant negative correlation between tumor regression rate and mean and minimum of Brevenh(-0.364~-0.413,P<0.05).When use TTP <55.23 s as a cutoff,we observed AUC=0.843 with sensitivity and specificity is 85.7% and 73.3% respectively in differentiating CR(n = 7) from others(n = 30).Conclusion: Semiquantitative parameters derive from DCE-MRI before treatment were capable to predict early treatment efficacy during concurrent chemoradiation in nasopharyngeal carcinoma, which has potential to be helpful in individualized therapy.