A comparison of endoanal ultrasound and computed tomography in staging rectal cancer and in clinical decision making - a preliminary study.

Abstract

The treatment options and the prognosis of rectal cancer (RC) depend mainly on the stage. Computed tomography (CT) has been the main staging tool in RC but endoanal ultrasound (EAUS) is thought to be more accurate. Patients with histologically proven rectal cancer presenting for the first time were staged using CT and EAUS. TNM staging was used to stage the rectal cancer. 24 patients (M:F 1:1) with a mean age of 57.3 (range = 23-80, SD = 15.3) years were included. The majority had a tumour of stage IIA/T3N0M0 (CT = 10, EAUS = 12). The staging of the tumour was the same in both investigations in 11 patients, while in 8 patients, EAUS staging was higher. The agreement for the T and N stages were kappa 0.24 and 0.5 respectively. There was a moderate and fair agreement between the overall TNM staging (weighted kappa 0.435) and the treatment strategies (weighted kappa 0.226) respectively, based on each imaging method. Of the 13 patients whose staging was different, the management changed in 6 (25%) patients (p = 0.016). CT identified distal metastases in 2 patients. EAUS and CT have only a fair to moderate agreement for staging and deciding treatment. However,EAUS has a significant influence when deciding treatment protocols.