The efficacy of preoperative computed tomography in patients with colorectal carcinoma.

A retrospective study was performed to evaluate and compare preoperative computed tomography (CT) scanning with less expensive tests that are used to identify hepatic metastases in patients with colorectal carcinoma. Thirty-three patients treated for colorectal carcinoma from January 1985 to December 1986 had preoperative CT scans performed as well as serum levels of lactose dehydrogenase (LDH), and carcinoembryonic antigen (CEA) measured. All patients underwent intraoperative evaluation of the liver. Only one patient had metastases found by CT exam that was not apparent at laparotomy. The sensitivity and specificity of the CT scan for detecting hepatic metastases were 1.00 and 0.96, respectively. The sensitivity and specificity of elevations in LDH or CEA when used in combination for detecting liver involvement was 1.00 and 0.54, respectively. Although the CT scan is effective in detecting hepatic metastases in patients with colorectal carcinoma we found that its routine use is unnecessary and expensive.