Accuracy of endorectal ultrasound after preoperative radiochemotherapy in locally advanced rectal cancer.
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.
Rau
B
B
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.
Hünerbein
M
M
Barth
C
C
Wust
P
P
Haensch
W
W
Riess
H
H
Felix
R
R
Schlag
P M
PM
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*