Clinical Application of Ultrasonic Probing for Preoperative Staging of Colorectal Carcinoma

The aim of this study was to assess the value of ultrasonic probing (USP) on colonoscopy for the preoperative staging of colorectal carcinoma. 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. 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. 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.