[Tumor staging and follow-up care in rectosigmoid carcinoma: colonoscopic endosonography compared to CT, MRI and endorectal MRI].

BACKGROUND AND STUDY AIMS: Endosonography has become the best available method for local staging of primary rectal cancer and diagnosing recurrent local tumor. The aim of this prospective study is to compare the accuracy of endoscopic ultrasound (EUS), using an echo colonoscope (CF-UM 3, CF-UM 20, Olympus optical) to computed tomography (CT), body coil magnetic resonance imaging (MRI) and endorectal coil magnetic resonance imaging (EMRI).

PATIENTS AND METHODS: From February 1991 to July 1993 90 patients with primary rectosigmoidal tumors (n = 32: 9 women, 23 men, mean age 68 years [range 37 to 84]) or follow-up examinations for recurrent local cancer (patients: n = 58, examinations: n = 93; 41 women, 52 men, mean age 61 years [range 31 to 84]) were investigated. The results of preoperative examinations were compared to histopathological findings regarding T and N stages.

RESULTS: In T staging, accuracy of EUS (78%) was superior to CT (50%) and equivalent to both MRI (75%) and EMRI (80%). The accuracy of EUS (84%) in assessing transmural tumor infiltration was superior to CT, MRT and EMRT (50%, 75% and 80%, resp.); however, CT (77%) and MRI (86%) were more accurate than EUS (64%) and EMRI (33%) in assessing N stages. Recurrent local cancer was found in 22 patients. All but one were detected by EUS. Sensitivity, specificity and accuracy in follow-up examinations for recurrent disease for EUS were 95%, 94% and 95%, for CT 75%, 73% and 74%, for MRI 57%, 100% and 70%, and for EMRI 83%, 100% and 90% resp.

CONCLUSIONS: Endoscopic ultrasound proved to be a safe and accurate method of preoperative staging and early diagnosis of recurrent rectal cancer and was superior or at least equivalent to CT, MRI and EMRI.