Accuracy of endorectal ultrasonography in the preoperative staging of rectal cancer

Background: Preoperative staging of rectal tumours is considered essential to tailoring treatment for individual patients. The aim of the present study was to evaluate the accuracy of 3-D-endorectal ultrasonography for the preoperative staging of rectal cancer. Methods: Three hundred and fifty-seven patients with rectal adenocarcinomas underwent an endorectal ultrasonography evaluation during a period of eight years. The evaluation was performed by four surgeons. We compared the endorectal ultrasonography staging with the pathology findings. Patients with preoperative chemoradiation were excluded from the study. Results: Overall accuracy in assessing the level of rectal wall invasion was 77.3%, with 9.3% of the tumours overstaged and 8.1% understaged. Accuracy in assessing nodal involvement in 313 patients treated with radical surgery was 74.9%, with 8.9% overstaged and 8.9% understaged. Conclusions: The accuracy of 3-D-endorectal ultrasonography in assessing the depth of tumour infiltration is good, but it is lower than previously reported. The technique is precise in distinguishing between benign tumours and invasive cancer. The results depend on the experience of the surgeon.