Value Of MSCT In Preoperative TNM Staging Of Rectal Carcinoma

PURPOSE: To evaluate the validity,reliability and performance of MSCT in peroperative staging (TNM) of rectal carcinoma.METHODS: Three hundred and one paitients with rectal carcinoma were diagnosed and treated consecutively in Department of Colorectal &Anal Surgery of Shanxi Province Tumour Hosipital during January 2009 and December 2009. Three hundred and one paitients with rectal carcinoma meet the inclusion criteria. All of them underwent MSCT of abdomen and pelvis and were staged in order to MSCT befor operation . We compared the MSCT staging with the final histpathological results in order to evluate the validity,reliability and performance of MSCT in preoperative staging(TNM) of rectal carcinoma.RESULTS: The sensitivity,specificity,positive likelihood ratio,negative likelihood ratio,positive predictive value,negative predictive value,area under curve of T staging are 64.7%,96.8%,20.22,0.36,80.5%,93.1%,0.808 for T2 staging tumors and 93.8%,75.0%,3.75,0.08,89.5%,84.2%,0.844 for pT3 staging tumors and 87.8%,98.1%,45.66,0.12,87.8%,98.1%,0.929 for pT4 staging tumors, respectively. The sensitivity,specificity,positive likelihood ratio,negative likelihood ratio,positive predictive value,negative predictive value,area under curve of N staging are 72.0%,91.2%,8.21,0.31,90.8%,73.1%,0.816, respectively. The sensitivity,specificity,positive likelihood ratio,negative likelihood ratio,positive predictive value,negative predictive value,area under curve of M staging are 92.7%,99.7%,265.31,0.07,92.7%,99.7%,0.963, respectively. CONCLUSION:MSCT is accurate for T3,T4 and M of the rectal cancer, comparedwith pathology. It's validity and reliability is best. MSCT is medium for T2 and N of the rectal cancer, compared with pathology. It's validity and reliability is wrong. MSCT is worst for substage of N, compared with pathology. MSCT cann't identify the liver metastasis, which is smaller than 5mm. The defect is obvious, to predict the infiltration of primary tumour,nodal metastasis and distant metastasis of rectal cancer using MSCT. So it is unsuitable for preoperative staging of rectal cancer, all alone.