Clinical application of ultrasonic probing for preoperative staging of colorectal carcinoma

OBJECTIVE: The aim of this study was to assess the value of ultrasonic probing (USP) on colonoscopy for the preoperative staging of colorectal carcinoma. METHODS: Seventy-five patients with colorectal carcinomas proven pathologically underwent USP (Olympus UM-2R, 12 MHz; UM-3R, 20 MHz) on colonoscopy before surgery for colorectal cancer. The results were compared with pathological findings of resected specimens. RESULTS: Colorectal carcinoma appeared as a hypoechoic mass on USP. USP had an overall accuracy rate of 82.7% for diagnostic T staging of colorectal carcinoma. In determining lymph node metastasis, the sensitivity and specificity were 53.2% and 61.5%, respectively. The positive and negative predictive values were 0.87 and 0.22, respectively. CONCLUSIONS: USP is valuable for the staging of colorectal carcinoma and has a high accuracy rate for determining the depth of tumour invasion. The preoperative information obtained by this tool may influence the choice of therapy.