Diagnostic Value Of CT In The Inguinal Lymph Node Metastasis And Clinical Analysis Of Vulvar Cancer

Objective:Inguinal lymph node metastasis has been the most significant factor for the staging,treatment and prognosis of vulvar cancer.We discussed the value of computerized tomography(CT)as a guide to further clinical diagnosis and treatment of vulvar cancer and analyzed the risk factors of inguinal lymph node metastasis.Methods:67 cases of patients with vulvar cancer from January 2006 until December 2017 from The Affiliated Cancer Hospital of Nanjing Medical University were retrospectively reviewed,to explore the value of preoperative CT and the influential factors of inguinal lymph node metastasis.Regarding the postoperative pathology as the gold standard,we explored the sensitivity,specificity,accuracy,positive predictive value and negative predictive value of CT to diagnose lymph node metastasis on a patient-by-patient basis and on a groin-by-groin basis respectively.Kappa statistics were calculated to describe the consensus.We used the receiver-operating characteristic curve(ROC)to look for the best threshold value for the cross-sectional diameter both on its long axis and on its short axis of inguinal lymph node from CT imaging in the diagnosis of node metastasis.The relationship between risk factors and inguinal lymph node metastasis was evaluated by both univariate and multivariate logistic regression,such as patients' age,squamous cell carcinoma antigen(SCC-Ag),tumor size and differentiation degree.Results:On a patient-by-patient basis,sensitivity,specificity,accuracy,positive predictive value and negative predictive value of CT to diagnose lymph node metastasis were 68.4%,75.0%,73.1%,52.0%,85.7%,respectively.On a groin-by-groin basis,sensitivity,specificity,accuracy,positive predictive value and negative predictive value of CT were 68.2%,81.3%,78.4%,50.0%,90.3%,respectively.The Cohen's kappa value calculated on a patient-by-patient basis was 0.396,on a groin-by-groin basis was 0.437.The ROC curve for the value of CT in the prediction of inguinal lymph node metastasis of vulvar cancer showed the area under the curve(AUC)to be 0.997 and 0.948 on its short axis and on its long axis of inguinal lymph node from CT imaging,respectively.The best threshold value for the cross-sectional diameter was 1.155cm on its short axis and 1.655cm on its long axis.The AUC>0.9 that indicated the notable significance of CT in the prediction of inguinal lymph node metastasis,furthermore,the diagnostic value on its short axis was higher.In a univariate logistic regression model,SCC-Ag was an influential factor of inguinal lymph node metastasis(P=0.007,P<0.05),patients' age,tumor size,and differentiation degree were not associated with inguinal lymph node metastasis.In a multivariate logistic regression model,SCC-Ag was an independent risk factor of inguinal lymph node metastasis,the best threshold value for SCC-Ag was 1.35ng/ml calculated by ROC curve.Conclusion:In view of the severe complications of inguinofemoral lymphadenectomy,it is of great clinical significance to carry out the risk assessment of inguinal lymph node metastasis before operation.The data of our study showed that preoperative CT was mainly based on the size of lymph node to evaluate lymph node metastasis,it was still informative for the operative treatment plan of vulva cancer.Patients' age,tumor size and differentiation degree had no effect on inguinal lymph node metastasis,only the SCC-Ag was conformed to be a risk factor.However,considering the postoperative pathology as the gold standard for clinical staging,surgical removal of inguinal lymph nodes can't be replaced.We are looking forward to the method which is more accurate to predict inguinal lymph node status before operation.We also hope for continuous improvement of surgery to improve patients'quality of life.