The Value Of DCE-MRI In Quantitative Evaluation Of Biological Behavior Of Soft Tissue Tumors

Objective By analyzing the correlation of quantitative parameters of dynamic contrast-enhanced MRI（DCE-MRI）with Microvessel density（MVD）and Ki-67 labeling index（Ki-67 LI）in soft tissue tumors（benign and malignant soft tissue tumors and low and high proliferation soft tissue sarcomas）,To explore the value of quantitative parameters of DCE-MRI in evaluating the biological behavior of soft tissue tumors.Methods The clinical data of 72 patients with soft tissue tumors confirmed by pathology in the Affiliated Hospital of Qingdao University from January 2017 to June 2020 were analyzed retrospectively,including 30 benign tumors and 42 malignant tumors.All patients were examined by routine MRI and DCE-MRI before the operation.The DCE-MRI parameters including volume transfer constant(K^trans),rate constant(K_ep)and extravascular extracellular volume fraction（V_e）were acquired by post-processing software analysis.MVD and Ki-67 LI were detected using immunohistochemical method.Spearman correlation test was used to analyze the correlation between DCE-MRI quantitative parameters and MVD and Ki-67 LI.χ²test or Fisher test was used to compare the difference of clinical data and routine MRI findings between benign and malignant groups,low and high proliferation groups.Independent sample t-test or Mann-Whitney U test was used to compare the difference of DCE-MRI quantitative parameters between benign and malignant groups,lowand high proliferation groups.Optimal cut-off points were determined using the area under the curve analysis for significant parameters.Results1.Compared with benign soft tissue tumors,the patients with malignant soft tissue tumors were older,the largest transverse diameter was more>5cm,the boundary was more ill-defined,T2 heterogeneity,and the peritumor edema was more common（P<0.05）.There was no statistical significance in gender,site,morphology and enhancement method（P>0.05）.2.There was positive correlation between K^trans,K_epand MVD（r=0.633,0.726,P<0.0l）,and positive correlation between K^trans,K_epand Ki-67 LI（r=0.558,0.612,P<0.01）.There was no correlation between V_eand MVD,Ki-67 LI（P>0.05）.3.The K^trans,K_epin the malignant group were higher than those in the benign group（P<0.05）.There was no significant difference in V_evalue between malignant group and benign group.When K^transvalue of 0.169/min was used,the sensitivity,specificity and area under the ROC curve（AUC）for differentiating benign and malignant soft tissue tumors were 84.6%,85.8%and 0.860,respectively.When K_epvalue of 0.369/min was used,the sensitivity,specificity and AUC were 92.3%,83.4%and 0.846,respectively.4.There was no significant difference in age,gender,the largest transverse diameter,T2 heterogeneity,necrosis and peritumoral enhancement between low and high proliferation groups（P>0.05）.5.There was no correlation between K^trans,K_ep,V_eand Ki-67 LI in low and high proliferation groups（P>0.05）.6.There was no significant difference in K^trans,K_ep,V_ebetween low and high proliferation groups（P>0.05）.Conclusions1.Routine MRI features can partly distinguish benign from malignant soft tissue tumors according to patient age,tumor maximum transverse diameter,boundary,T2heterogeneity,and periumoral edema.2.In the evaluation of benign and malignant groups by DCE-MRI quantitative parameters,K^transand K_epare correlated with MVD and Ki-67 LI,K^transand K_epcan partly reflect the angiogenesis and cell proliferation of soft tissue tumors.The difference of K^transand K_epbetween benign and malignant groups was statistically significant,and K^transand K_epcan distinguish benign and malignant groups.3.In the evaluation of low and high proliferation groups by DCE-MRI quantitative parameters,K^trans,K_epand V_ewere not correlated with Ki-67 LI,and the difference of K^trans,K_epand V_ebetween the low and high proliferation groups were not statistically significant.DCE-MRI quantitative parameters have limited value in evaluating the proliferative of soft tissue sarcomas.