Evaluation Of Efficacy Of Intravoxel Incoherent Motion Imaging In Preoperative Neoadjuvant Chemoradiotherapy For Esophageal Cancer And Correlation Study Of Pathological Indexes

Background and purpose:Esophageal cancer is a common malignant tumor of the digestive tract in China.Currently,it ranks the seventh in morbidity and the sixth in mortality in the world.Since the symptoms of early esophageal cancer are not obvious and the invasion ability is strong,the patients who are first diagnosed clinically often enter the middle and advanced stages.Clinical often the preferred surgical procedure for resectable esophageal cancer,but in recent years,the emergence of neoadjuvant chemoradiotherapy for esophageal cancer patients with long-term survival and tumor resection rate provides a better improvement,for patients with individual differences,different patients have different sensitivity to neoadjuvant chemoradiotherapy,so seeking a noninvasive imaging in preoperative evaluation method for the treatment of individual precision has an important significance.Intravoxel incoherent motion imaging(IVIM)is through the separation of blood vessels and organization of water molecules in functional magnetic resonance imaging,which can be used to reflect the internal perfusion of the tumor,microscopic monitoring can be performed to the esophageal cancer neoadjuvant chemoradiotherapy curative effect,and the forecast index of pathology after treatment,the further help clinical setting or change the treatment strategy.The purpose of this study was to explore the application of IVIM parameters in predicting the efficacy of neoadjuvant chemoradiotherapy and pathological indexes of esophageal cancer.Part1:Preliminary study on the prediction of neoadjuvant chemoradiotherapy for esophageal cancer by intravoxel incoherent motion imagingObject:To investigate the predictive value of intravoxel incoherent motion imaging(IVIM)parameters in neoadjuvant chemoradiotherapy for esophageal cancer.Material and methods:41 patients with esophageal cancer were prospectively enrolled.The diffusi on parameters including apparent diffusion coefficient(ADC),true diffusion co efficient(D),pseudo diffusion coefficient(D*)and pseudo diffusion component fraction(f)were obtained.The tumors were graded as 1～5 according to tumo r regression grade(TRG)after neoadjuvant chemoradiation by surgical specimen s.Univariate t-test or Mann-Whitney U test was used to analyze the difference.P<0.05 was statistically significant.Results:Among the IVIM parameters,post-ADC value and post-D value were high er than pre-ADC value and pre-D value.Compared with the no-pCR group,th e pre-ADC,pre-D,post-D and AD was statistically significant in the pCR gro up(p<0.05).We saw similar results in the comparison between GR group and no-GR group.The efficacy of post-D and AD values was better than others.T here was statistically significant difference in the D value of TRG parameters at all levels after chemoradiotherapy(P<0.05).They are negatively correlated,t he correlation coefficient was 0.532(P<0.05).The area under curve of △D valu es has best diagnostic efficiency,which diagnose pCR and no-pCR,GR and n o-GR were 0.856 and 0.866 respectively;Sensitivity and specificity were 60.0%100%and 66.7%,94.1%respectively.Conclusion:The parameters of intravoxel incoherent motion imaging can be used to pr edict the efficacy of neoadjuvant chemoradiotherapy in patients with esophageal cancer,among which the △D value has the highest diagnostic efficacy.Part2: Correlation of IVIM parameters with VEGF and MVD in esophageal cancerObjective:To investigate the correlation between the multi-parameter value of intravoxel incoherent motion(IVIM)and the expression of VEGF(vascular endothelial growth factor)and MVD(microvessel density)in esophageal carcinoma.Methods:Thirty-six patients with esophageal cancer were collected,all of whom were confirmed by gastroscopy preoperatively and underwent 3.0TMR routine sequence and IVIM sequence scanning for esophageal cancer.The expressions of VEGF and MVD were detected by immunohistochemical staining,and the correlation between IVIM quantitative parameters and the expressions of VEGF and MVD was analyzed by Spearman rank correlation analysis.P<0.05 was the standard for statistical difference.Results:The IVIM parameter values of ADC,D,D*and f were(1.562±0.379)×10-3mm2/s,(0.942±0.285)×10-3mm2/s,(20.394±9.686)×10-3mm2/s and(0.505±0.109),respectively.The measured values of VEGF and MVD were(5.556±0.695)and(37.389±22.360),respectively.VEGF was positively correlated with D*value(r=0.335,P=0.046).VEGF has no correlations between ADC value、D value and f value(P>0.05);MVD was positively correlated with D*value(r=0.374,P=0.024)and f value(r=0.387,P=0.020),the MVD has no correlation between ADC value and D value(P>0.05).Conclusion:D*and f were positively correlated with VEGF and MVD in esophageal cancer.Quantitative parameters D*and f of intravoxel incoherent motion can indirectly reflect angiogenesis of esophageal cancer,which can be used as imaging indexes for noninvasive prediction of VEGF and MVD before surgery.