title: [Place of endorectal ultrasonography in the evaluation of staging of cancer of the rectum: before or after preoperative radiotherapy?].
abstract: Of 62 patients with rectal carcinoma, who were examined by endorectal ultrasound (EER) before operation, 15 were examined after preoperative external radiation therapy. The results were compared to histological and surgical findings according to the TNM classification. When preoperative radiation therapy was not applied, the diagnostic value of EER was excellent, as well as for the detection of perirectal fat spread as for lymph node involvement. The diagnostic accuracy was respectively 87.2% (CI: 74-95) and 78.0% (CI: 62-90). After irradiation, the diagnostic value was much lower. The diagnostic accuracy was 60% (CI:33-84) and 40% (CI:18-68) for perirectal fat spread and nodal involvement, respectively. This loss of information was due to a decrease in specificity. Radiation treatment was responsible for the occurrence of hypoechoic nodal images and peritumoral hypoechoic areas resulting in an overestimation of the extent of involvement. After irradiation of a rectal malignant tumor, the classical EER signs are no longer adequate to predict locoregional involvement. Endosonographic semiology must be modified to describe the tumor response to non surgical treatment.
authors.affiliation: Service d'Hépato-Gastroentérologie, Centre Hospitalier Universitaire, Angers.
authors.forename: P
authors.initials: P
authors.lastname: Burtin
authors.forename: P
authors.initials: P
authors.lastname: Cellier
authors.forename: A
authors.initials: A
authors.lastname: Croue
authors.forename: J P
authors.initials: JP
authors.lastname: Arnaud
authors.forename: S
authors.initials: S
authors.lastname: Carpentier
authors.forename: J
authors.initials: J
authors.lastname: Boyer
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011182:Postoperative Care; D011300:Preoperative Care; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D014463:Ultrasonography
vernacular_title: Place de l'échographie endorectale dans le bilan d'extension du cancer du rectum: avant ou après radiothérapie pré-opératoire?