title: Accuracy of endorectal ultrasound after preoperative radiochemotherapy in locally advanced rectal cancer.
abstract: OBJECTIVE
  Factors limiting the accuracy of endorectal ultrasound in staging, locally advanced primary rectal cancer after preoperative neoadjuvant radiochemotherapy (RCT) were evaluated.
  
  
  METHODS
  Patients (n = 84) with initial locally advanced rectal cancer (uT3/uT4) undergoing R0 resection were investigated after preoperative treatment that combined radiotherapy up to 45 Gy with two cycles of chemotherapy (5-FU and leucovorin on d 1-5 and 22-28). At 4 to 6 weeks after completion of RCT and before tumor resection, preoperative endoluminal ultrasound was performed.
  
  
  RESULTS
  The accuracy to predict the depth of tumor infiltration (T-category) was found to correlate with downstaging. The T-category was correctly staged before surgery in 15 of the 51 responders (29%) and in 27 of 33 nonresponders (82%), whereas misinterpretation occurred in 36 of the responders (71%) and in 6 of the nonresponders (18%) (p < 0.001). Neither tumor distance from anal verge nor tumor location correlated with the staging accuracy. Lymph node involvement was correctly assessed in 48 patients (57%). Wall invasion was correctly ascertained in 42 patients (50%), with under estimation in 11 patients (13%) and overestimation in 31 patients (37%).
  
  
  CONCLUSIONS
  After radiochemotherapy, endosonography does not provide a satisfactory accuracy for preoperative staging of rectal cancer. New interpretation and diagnostic criteria are needed for the prediction of treatment response.
authors.affiliation: Division of Surgery and Surgical Oncology, Charité Campus Buch, Robert-Roessle Hospital and Tumor Institute of Humboldt University at Berlin, Lindenberger Weg 80, 13122 Berlin, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Rau
authors.forename: M
authors.initials: M
authors.lastname: Hünerbein
authors.forename: C
authors.initials: C
authors.lastname: Barth
authors.forename: P
authors.initials: P
authors.lastname: Wust
authors.forename: W
authors.initials: W
authors.lastname: Haensch
authors.forename: H
authors.initials: H
authors.lastname: Riess
authors.forename: R
authors.initials: R
authors.lastname: Felix
authors.forename: P M
authors.initials: PM
authors.lastname: Schlag
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D017024:Chemotherapy, Adjuvant; D019160:Endosonography; D006801:Humans; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D011300:Preoperative Care; D018714:Radiotherapy, Adjuvant; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*