The Role Of Siral CT And VEGF NVD Assay In Preoperative Staging For Advanced Colorectal Carcinoma

Objective:To detemine the value of spiral CT in staging of colorectal carcinoma. To investigate the expression of vascular endothelial growth factor (VEGF) and microvessel density (MVD) in colorectal carcinoma, and to study its relationship with the enhancement degree of the lesion on SCT scan. Methods: 30 patients that are colorectal carcinoma been confirmed by colonofibroscope or operation, all of them were examined by SCT, and the preoperative staging of TNM were used based on the finding of SCT. The results of SCT were compared with those of surgical and pathological examination in all cases. Result: 24 cases of 30 patients were correctly staged with TNM ,the accuracy was 80%, the accuracy was 80.77%(21/16) in T stage, the accuracy was 69.23%(18/26) in N stage and the accuracy was 96.67%(29/30) in M stage. All of them were examined by SCT, and the CT attenuations were measured. The resected tumor specimens were immunohistochemically stained with CD34 for measuring MVD and stained with VEGF. The result were compared with the enhancement degree of the lesions observed on SCT scan The enhancement correlated well positively with MVD and VEGF of the colorectal carcinoma. Conclusion: Spiral CT is better method of depicting the colorectal carcinoma, it allows for accurate depiction and staging of colorectal carcinoma, especially detecting the invasion of adjacent tissues and distant metastasis, however the value of SCT for early T staging in colorectal carcinoma and minute metastasis of lymph nodes or peritonei is limited. High expression of VEGF and MVD is a biological label of malignancy. The degree of enhancement correlated closely with the blood supply and MVD VEGF of colorectal carcinoma. Spiral dynamic CT scan can demonstrate the enhancement characteristics of colorectal carcinoma .