Prognostic Value Of Diffusion-weighted MRI Combines With Tumor Volume For The Short-term Treatment Response Of Nasopharynx In Nasopharyngeal Carcinoma

Background Diffusion-weighted(DW)MRI can be used to predict the short-term treatment response in nasopharyngeal carcinoma(NPC),and the volume of tumor is also certified as an indicator of prognosis.And report that combine these two factors together is yet to be established.Therefore,we made an incorporation of MRI-DWI and tumor volume,and set up an integrated model,in order to explore the predictive value of these two factors.Objective To investigate the prognostic value of MRI-DWI combine tumor volume for the(NPC).Methods 94 patients with NPC were prospectively enrolled,MRI-DWI were performed before their treatment,tumor volume of nasopharynx was recorded as well.MRI was performed again after treatment,according to RECIST 1.1,response rates were assessed.Patients were divided into complete remission group(CR)and non CR group,the predictive ability of tumor volume of nasopharynx and ADC value and their combination was analyzed.RESULTS The pretreated value of ADC,gross tumor volume of nasopharynx(GTVnx)and gross tumor volume of nasopharynx with retropharyngeal lymph nodes(GTVnx+RLN) showed statistical difference between CR group and non CR group.When the cut-off value of ADC,GTVnx and GTVnx+RLN were 0.894×10-3mm2/s,17.856 ml and 13.075 ml,AUC were 0.656,0.678 and 0.699 respectively.AUC reached 0.772 when we combined ADC with GTVnx+RLN.We further incorporated ADC value and GTVnx+RLN by constructing nomogram,C-index were 0.770.There is no correlation between avg ADC with GTVnx/GTVnx+RLN.Plus,avg ADC gets higher after treatment in part of the case in non CR group.CONCLUSION The combination of pretreated ADC value and GTVnx+RLN can be used to predict the treatment response in nasopharyngeal carcinoma.