Accuracy of Surveillance Computed Tomography in Detecting Recurrent or New Primary Lung Cancer in Patients with Completely Resected Lung Cancer

Background: To determine the eventual outcome of abnormalities detected on surveillance computed tomography (CT) in patients with previously resected nonsmall-cell lung cancer (NSCLC), and to assess the accuracy of CT when used by the thoracic surgeon, and to determine the characteristics of abnormalities on CT that correlate with the development of recurrent NSCLC.

Methods: A cohort of patients who had abnormal postoperative CT scans of the chest and upper abdomen in 2002 were followed up into 2005. Abnormalities consisted of pulmonary nodules, pleural effusions, or adenopathy. Data collected included recurrence patterns, the availability of previous scans for comparison, the interval between initial resection and the abnormal CT, nodule size, growth, and multiplicity, as well as progression of pleural effusions or adenopathy.

Results: In all, 105 scans in 92 patients were read as abnormal in 2002 by the radiologist. After further investigation or follow-up, or both, for a mean of 3.2 years, 78% of patients who had recurrent NSCLC had their site of first recurrence inside the chest. The negative predictive value of CT when used by the thoracic surgeon was 99%; however, the positive predictive value was only 53%. Abnormalities that correlated with the diagnosis of recurrent cancer included pulmonary nodules that either grew or were larger than 1 cm and pleural effusions that developed after the first postoperative year.

Conclusions: Intrathoracic recurrent NSCLC was rarely missed by the surgeon utilizing surveillance CT, but a significant number of negative investigations were generated by its use. Characteristics of abnormal surveillance CT findings exist that correlate with the presence of malignancy.