Evaluation of intra-rectal ultrasonography in pre-operative staging of cancer rectum.

ABSTRACT

Intra-rectal ultrasonography was used in the preoperative staging of 20 patients with rectal cancer, using a 4 MHz radial scanner. The results of ultrasonic staging were compared with clinical examination including EUA, operative and subsequent histological staging. The lesion could not be felt by digital examination in 6 patients. In the remaining 14 patients ultrasound examination matched the digital examination and EUA and was sometimes superior to it. As regards the degree of invasion of the rectal wall layers, ultrasonography corresponded with the histopathologic findings in 10 of the resected 11 tumors [accuracy rate 90.9%]. Concerning regional lymph node infiltration, the accuracy rate of endorectal sonography was 85% with only one false positive and two false negative cases. Intra-rectal ultrasonography is a highly accurate preoperative staging tool for rectal cancers both in delineating the depth of tumor invasion and subsequently its resectability, and in assessing regional lymph nodes. It is particularly valuable in tumors non reachable by the examining finger