Staging of Colorectal Carcinoma by Spiral CT with Water Enema: Correlation with Pathologic Staging Using New AJCC Classification

Kim, Hyoung Jung; Lee, Dong Ho; Ko, Young Tae

Abstract

PURPOSE: In cases of colorectal cancer, to correlate the spiral CT staging with water enema with thepathologic staging according to the new AJCC classification.
MATERIALS AND METHODS
Ninety four patients withpathologically proven carcinoma of the colon who had un-dergone spiral CT with water enema were evaluated. CTscans were obtained after enema involving about 600-1,200mL of water. Scanning was performed from thediaphragmatic dome to the symphysis pubis using 10mm collimation thickness, 12mm table feed, and 10mmreconstruction interval. The TNM stage, as seen on spiral CT, was determined without reference to the pathologicresults. Staging was performed according to the new AJCC cancer staging manual(1997). The pathologic T-stage wasT1 in four cases(4.3%), T2 in 11(11.7%), T3 in 72(76.6%), and T4 in seven(7.4%). The pathologic N-stage was N0 in57 cases(60.6%), N1 in 25 cas-es(26.6%), and N2 in 12(12.8%). The pathologic M-stage was M0 in 90 cases(95.7%) andM1 in four(4.3%).
RESULTS
The detection rate of colon cancer using spiral CT with water enema was 97.9%. At theT-stage, pathologic correlation was good in 68.1% of cases(64/94). Nine patients(9.6%) were overstaged and21(22.3%) were understaged. At the N-stage, pathologic correlation was good in 54.3% of cases(51/94), with 27pa-tients(28.7%) overstaged and sixteen(17.0%) understaged. At the M-stage, pathologic correlation was good in95.7% of cases(90/94). Four patients(4.3%) were overstaged.
CONCLUSION
The accuracy of staging of colorectalcarcinoma by spiral hydro-CT was 68.1% at the T-stage, 54.3% at the N-stage, and 95.7% at the M-stage. As seen onspiral CT with water enema, the T-stage tended to-wards understaging and the N-stage towards overstaging.