Applications And Prognostic Analysis Of Nasopharyngeal Carcinoma Retropharyngeal Lymph Nodes Based On Magnetic Resonance Apparent Diffusion Coeffect

Objective：With the wide application of magnetic resonance imaging (MRI), functionalmagnetic resonance imaging also gradually is used in clinical.this study applydiffusion-weighted imaging (DWI) apparent diffusion coeffiient(ADC) value toevaluate the retropharyneal lymph nodes.and Explore the prognostic relation ofclinical and pathological features of patients、the retropharyngeal lymph node size andpharyngeal lymph node ADC value with nasopharyngeal carcinomaMethods：Retrospective analysis of80patients received platinum-based concurrentchemoradiotherapy in patients with nasopharyngeal carcinoma.115cases of80patients measurable retropharyngeal lymph nodes after treatment1month,3months,6months,12months,24and36months was followed-up. lymph node size wasassessed using evaluation criteria of Solid Tumors (RECIST).change of ADC valuesbefore treatment and after3months use paired samples t-test, p <0.05wasstatistically significant. SPSS17.0Kapla-Meier method analysis overall survival (OS)and distant metastasis free survival (DMFS).Results:1、by observing115retropharyngeal cases lymph node changes to determinetheir benign and malignant. before treatment and after treatment3months, to observechanges by comparing lymph node ADC value.the difference was statisticallysignificant (p <0.001) between valid and invalid,The difference was statisticalsignificance (p=0.872).analysis the relationship of ADC value change and efficacybefore and after treatment, the results found effective changes in ADC values higherthan ineffective ADC values changes, there was a statistical difference (p <0.001).2.80patients according to age, sex, KPS score, N, T stage univariate analysisOS and DMFS，N stage is associated with OS(p <0.01) and DMFS (p <0.01). 3. the shortest diameter of115retropharyngeal lymph nodes of80patients (ifany bilateral retropharyngeal lymph nodes, to take the shortest diameter of thesmallest lymph node)>0.6cm,≤0.6cm; lymph ADC values>0.9×10-3mm2/s，≤0.9×10-3mm2/s univariate analysis of OS and DMFS,. The results show thatindependent of lymph node size and OS (p=0.900) and DMFS (p=0.826). ADCvalue is not associated with OS (p=0.811) and DMFS (p=0.795).4.Subgroup of univariate analysis the shortest diameter>6mm in63patientswith positive lymph nodes according to the follow-up results.show thatretropharyngeal retropharyngeal lymph nodes sizeis is associated with OS (p=0.010)and not associated with DMFS (p=0.056). Subgroup analysis in59cases of patientswith positive lymph nodes in the retropharyngeal ADC values≤0.9×10-3mm2/s,ADC value is not associated with OS (p=0.118) and DMFS (p=0.116).5. multivariate analysis show the retropharyngeal positive lymph node theshortest diameter is independent prognostic factor of overall survival.Conclusion：1. ADC values may be used to evaluate the retropharyneal lymph nodes.2The retropharyngeal positive lymph node the shortest diameter>12mm isindependent prognostic factor.