Preoperative staging of rectal cancer: Role of 3D endorectal ultrasonography

Endorectal ultrasonography has become important part of preoperative staging of rectal cancer, providing adequate information for clinical decision-making in many cases. However, with the currently available ultrasonographic equipment and techniques, a good deal of relevant information may remain hidden. The advent of high-resolution three-dimensional endoluminal ultrasound, constructed from a synthesis of standard two-dimensional cross-sectional images, and of "Volume Render Mode," a technique to analyze information inside a three-dimensional volume, promises to improve the accuracy of rectal cancer staging. The anatomic structures in the pelvis, the axial and longitudinal extension of the tumor, the presence of slight or massive submucosal invasion in early rectal cancer may be imaged in greater detail. This additional information will bring an improvement for both planning and conduct of surgical procedures.