Related Experiment Videos
Staging of rectal cancer after polypectomy: usefulness of endorectal US
J B Kruskal1, S M Sentovich, R A Kane
1Department of Radiology, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA.
Purpose:
To determine the usefulness of endorectal ultrasonography (US) in staging rectal cancer discovered at polypectomy.
Materials And Methods:
Before surgical resection, endorectal US was performed in 18 consecutive patients with adenocarcinoma discovered in polypectomy specimens. A rotating 7-10-MHz endoprobe with an inflatable balloon was used in all cases. The precise depth of penetration (T stage) was determined with endorectal US and correlated with the histopathologic findings.
Results:
For detection of residual tumor after polypectomy, endorectal US had a sensitivity of 100%, specificity of 44%, positive predictive value of 64%, and negative predictive value of 100%. Although the precise T stage was correctly predicted with endorectal US in only eight patients (44%), endorectal US was able to demonstrate whether the tumor was limited to the bowel wall in 16 patients (89%).
Conclusion:
Endorectal US is an accurate technique for localizing tumors to or beyond the rectal wall in patients who have undergone diagnostic polypectomy. Although inaccuracies in determining the specific T stage may occur, endorectal US facilitates surgical planning in the vast majority of patients and should therefore remain the local staging technique of choice in this specific patient population.