Screening for asymptomatic early bronchogenic carcinoma with low dose CT of the chest

BACKGROUND. Survival of patients with lung carcinoma is very poor, particul arly for patients with advanced disease. There are no early clinical sympto ms, and screening with chest radiography has not been recommended. Computed tomography (CT) is superior to radiography for detection of pulmonary nodu les but usually is associated with relatively high radiation exposure. Rece ntly, accuracy of low dose CT has been shown to be similar to conventional dose CT. The goal of the current study was to assess the findings of low do se CT of the chest in heavy smokers. METHODS. More than 700 heavy smokers (> 20 pack years; age: > 40 years) und erwent unenhanced low dose CT of the chest. Detected nodules were classifie d according to their density (soft tissue, calcified, fat) and size (< 6 mm , 6-10 mm, > 10 mm). In nodules larger than 10 mm with no CT features to su ggest a benign lesion, histology was obtained. RESULTS. In approximately 40% of smokers, nodules smaller than or equal to 10 mm were detected. None was resected. In less than 3% of individuals, les ions larger than 10 mm were detected; 8 were bronchogenic carcinoma. All ei ght carcinomas were resectable. Lesions for which no histology was obtained were followed with low dose CT. CONCLUSIONS. Low dose CT detected 8 bronchogenic carcinomas in more than 70 0 heavy smokers. All eight were resectable. Pulmonary nodules measuring up to 10 mm were found in 40% of smokers. The significance of these small lesi ons has remained unclear. Cancer 2000;89:2483-4. (C) 2000 American Cancer S ociety.