[Staging for locoregional extension of rectal adenocarcinoma].

The treatment of rectal carcinoma is mainly determined by its local extension. Preoperative staging of rectal carcinoma was assessed by different methods: digital rectal examination, transrectal ultrasound, computed tomography, and magnetic resonance imaging. Digital rectal examination had a diagnostic accuracy between 68 and 83 per cent. The accuracy of transrectal ultrasound was between 67 and 93 per cent for tumor staging and between 62 and 88 per cent for lymph node staging. The accuracy of computed tomography was between 33 and 77 per cent for tumor staging and between 22 and 73 per cent for lymph node staging. The overall accuracy of magnetic resonance imaging with body coil was between 59 and 95 per cent, and between 39 and 95 per cent for lymph node staging. Use of an endorectal coil allows a slightly more consistent degree of accuracy, with tumor staging accuracy between 66 and 91 per cent, and lymph node staging accuracy between 72 and 79 percent. Preoperative radiation therapy makes transrectal ultrasound and computed tomography less effective as staging techniques.