Research On Prediction Of MSCT In Preoperative TNM Staging And Circumferential Resection Margin Of Rectal Cancer

ObjectiveTo predict the preoperative TNM staging and circumferential resection margin(CRM) of rectal cancer by normalized enhanced scanning of Multislice Spiral Computed Tomography (MSCT) for patients with rectal cancer, study the coincidence with postoperative pathology and then investigate it’s value preliminary and formulate more reasonable therapeutic schedules in clinic, which refers to the7th TNM staging system for rectal cancer of Union for International Cancer Control (UICC) and American Joint Committee on Cancer (AJCC) in2010.Methods91patients with whole clinical data and the postoperative pathologically proven rectal cancer between July2012and December2013in department of general surgery of our hospital were collected for study. CT images of plain scan, arterial phase, venous phase and delayed phase of all the91patients which acquired by preoperative MSCT plain and enhanced scanning can be used for Multi Planar Reformation (MPR) and Curved Planar Reformation (CPR). Compare the results of predictions of TNM staging and circumferential resection margin that enforced by2attending or above physicians of radiology by analyzing CT images and postoperative pathology, and analyze the accuracy rate, sensitivity, specificity, positive predictive value and negative predictive value in prediction of preoperative MSCT and the consistency of preoperative MSCT and postoperative pathology by statistics.Result1. Comparison for T staging of preoperative MSCT and postoperative pathology for rectal cancer:Accuracy rate of total T staging was86.8%(79/91);76.0%(19/25) for <T2,89.7%(35/39) for T3,92.6%(25/27) for T4. Kappa test showed that there’s consistency in T staging between preoperative MSCT and postoperative pathology (P<0.001):Preferably consistency in≤T2staging (Kappa value=0.742); Excellent consistency in T3and T4staging (T3Kappa value=0.823, T4Kappa value=0.895).2. Comparison for N staging of preoperative MSCT and postoperative pathology for rectal cancer:Accuracy rate of total N staging was78.0%(71/91);83.3%(30/36) for N0,74.3%(29/39) for N1,75.0%(12/16) for N2. Kappa test showed that there’s consistency in N staging between preoperative MSCT and postoperative pathology (P<0.001):Excellent consistency in NO (Kappa value=0.768); Preferably consistency in N1and N2staging (N1Kappa value=0.665, N2Kappa value=0.612).3. Comparison for M staging of preoperative MSCT and postoperative pathology for rectal cancer:Accuracy rate of total M staging was98.9%(90/91);98.7%(81/82) for M0,100%(9/9) for Ml. Kappa test showed that there’s consistency in M staging between preoperative MSCT and postoperative pathology (P<0.001):Excellent consistency in M0and Ml staging (MOKappa value=0.946, M1Kappa value=0.950).4. Comparison for CRM assessment of preoperative MSCT and postoperative pathology for rectal cancer:Accuracy rate of CRM assessment was60.5%(23/38). Kappa test showed that there’s consistency in M staging between preoperative MSCT and postoperative pathology (P<0.001):Preferably consistency in CRM+(CRM+Kappa value=0.657).Conclusion1. Fine consistency exists in T staging of preoperative MSCT and postoperative pathology for rectal cancer. Although there’s some limitation in T1and T2staging of rectal cancer which should not distinguish T1and T2lesion, high accuracy rates in T3and T4staging exist. Accuracy rate of total T staging is relatively high.2. Preferably consistency exists in N staging of preoperative MSCT and postoperative pathology for rectal cancer which is often the difficulty in preoperative staging of rectal cancer. Comparing to the others examination, MSCT is the major selection for N staging of rectal cancer although some false-negative and false-positive appear in judging lymphatic metastasis.3. Fine consistency exists in M staging of preoperative MSCT and postoperative pathology for rectal cancer. MSCT has obvious advantages in discovering distant metastasis for which it can discover the metastatic lesions in pelvic cavity, abdominal cavity and other places by characteristics of high density and space resolution and comprehensive application of several post-processing software.4. Preferably consistency exists in CRM prediction of preoperative MSCT enhancement scanning and postoperative pathology for rectal cancer. However, tumors in anterior rectal wall and metastatic lymph nodes close to circumferential resection margin influence the veracity of prediction in circumferential resection margin with MSCT. MSCT is one of the imaging procedures that can be valid predictions of CRM, which is cheaper and spending less check time.5. Fine TNM staging of rectal cancer can be confirmed by MSCT enhancement scanning with water filling in rectum. Fine consistency in T3, T4and M staging and preferably consistency in N staging and CRM prediction exist between it and postoperative pathology. MSCT can formulate more reasonable therapeutic schedules in clinic by preoperative preferably staging for rectal cancer.6. According to the results of this study, we recommended the specification MSCT examination and diagnosis for rectal cancer patients (the MSCT examination and diagnosis of rectal cancer standardized flowchart for Table Ⅲ).