The Role of Preoperative Chest CT in the Evaluation of a Colorectal Adenocarcinoma

Park, Jae Woo; Moon, Sun Mi; Hwang, Dae Yong

Abstract

PURPOSE
The most common metastatic site of colorectal adenocarcinomas is the liver, and the next common site is the lung. Pulmonary metastasis has been reported to be more common in rectal cancer (esp. lower rectum) than in colon cancer, and for pulmonary survival metastasis, a hepatic metastatectomy results in longer. Likewise, for hepatic metastasis, a pulmonary metastatectomy may prolong survival, and many reports of longer survival after a pulmonary metastatectomy have been published. We compared chest CT to chest PA as a preoperative diagnostic tool for the detection of pulmonary metastasis. METHODS: The retrospective analysis was done for 369 consecutive patients with preoperative chest CT and chest PA who had a histologically-proven adenocarcinoma. RESULTS: The detection rates of pulmonary metastases by preoperative chest PA and preoperative chest CT were 3.5% (13/369) and 8.4% (31/369), respectively. Pulmonary metastases were confirmed by surgical pathology and follow up for over 6 months to have occurred in 22 patients. Chest PA's sensitivity and specificity for metastasis of colorectal cancer were 45% and 99%, respectively, and the positive predictive value was 76.9%. Chest CT had a sensitivity of 86%, a specificity of 96%, and a predictive positive value of 61.2% for pulmonary metastasis. CONCLUSIONS: Chest CT was more sensitive than chest PA in identifying pulmonary metastasis. Also, the detection rate for pulmonary metastasis by using chest CT was higher than that by using chest PA. Chest CT may be more useful in the diagnosis of pulmonary metastasis than chest PA as a preoperative work-up tool. The preoperative chest CT may help surgeons make decisions in the treatment for patients with a colorectal adenocarcinoma.