Influence of endorectal ultrasound on surgical treatment of rectal cancer.

Refined surgical treatment of carcinoma of the rectum, such as sphincter-preserving operations, pouch anal anastomosis, and pre-operative irradation require exact assessment of tumor and lymph-node involvement before therapy. To improve pre-operative staging we used endorectal ultrasound to determine the depth of tumor infiltration and the presence of lymph-node metastases. A 7.0 MHz transducer (Bruel and Kjaer, Denmark) was used in the pre-operative staging of 110 patients with rectal carcinomas. In 90% of the cases it was possible to perform a correct tumor staging pre-operatively in comparison with histopathology. Sensitivity for detection of perirectal fat infiltration was 96% and the negative predictive value was 96%. Lymph-node involvement was accurately identified in approximately 80% of the cases. Endorectal ultrasound is a highly accurate tool in the pre-operative staging of rectal carcinoma, as well as in the detection of lymph-node involvement. It will identify patients suitable for sphincter-saving procedures or local treatment and define those with a considerable risk of local recurrence, where combined surgery and radiotherapy may be considered.