Influence of tumor position on accuracy of endorectal ultrasound staging

Abstract

Endorectal ultrasound is currently the best method for preoperative assessment of the depth of infiltration of rectal tumors. However, rectal anatomy seems to affect staging accuracy in the lower rectum because the structure of the ampulla recti renders endosonographic examination more difficult. In addition, endosonographic layers are less well defined at this level. Both factors contribute to a lower reliability and predictive value of endorectal ultrasound staging in the lower rectum, although statistical significance was not reached in this study. On the other hand, tumor position with respect to rectal circumference does not influence the predictive value of endorectal ultrasound.