ROLE OF CHEST CT IN PATIENTS WITH NEGATIVE CHEST X-RAYS REFERRED FOR HEPATIC COLORECTAL METASTASES

Background: Hepatic resection is the standard treatment for hepatic co lorectal metastases. The lung represents the next most likely site, af ter the liver, of metastatic disease. Computed tomography (CT) of the chest is more sensitive than is chest x-ray in detecting metastatic lu ng lesions. However, the usefulness of chest CT in the evaluation of p atients before hepatic resection remains uncertain. Methods: One hundr ed consecutive patients with negative chest x-rays and potentially res ectable hepatic colorectal metastases underwent chest CT. Patients wit h CT findings suggestive of metastatic disease were subjected to thora cotomy or video-assisted thoracic surgery (VATS) before laparotomy and attempted hepatic resection. The operative findings and clinical cour se were analyzed. Results: Eleven of 100 patients had a positive chest CT. Four of these Il patients had malignant lesions of the lung (thre e metastatic colorectal cancers and one primary lung cancer). There wa s no difference in median total hospital stay (8.5 days [range 7 to 13 days] vs. 8.0 days [range 3 to 49 days]), number of perioperative dea ths (0 vs. 2 deaths), or long-term outcome between those patients with a positive chest CT undergoing thoracotomy/VATS and those patients wi th a negative chest CT. Overall, chest CT provided a positive yield of 4% and a positive predictive value of 36% for the detection of malign ant lesions of the lung. Conclusions: Chest CT only minimally improved detection of malignant lesions of the lung over chest x-ray. Thoracot omy/VATS and wedge resection of lung nodules did not adversely affect outcome. The low positive yield and low positive predictive value of c hest CT in the setting of a negative chest x-ray places in question th e usefulness of routinely performing chest CT as part of the extent-of -disease work-up before hepatic resection.