Low-dose computer tomography as a screening tool for lung cancer in a high risk population

The aim of the study was to evaluate the usefulness of low-dose computer tomography as a screening tool for early stage lung cancer. The study was performed in 332 individuals aged 55-70 who were asymptomatic, who had not previously suffered from cancer, and who smoked at least ten packs of cigarettes a year. Baseline and repeated LD-CT scans were performed. Pulmonary nodules were classified according to the size and morphology, and the results were categorized as negative (no nodules observed), semi-positive (nodules of 4 mm or smaller in diameter) and positive (nodules 5 mm or larger). Based on the category of the patient, either a repeat low-dose CT, a bronchoscopy with or without a biopsy, or a PET-CT was performed. The baseline screening showed 59 positive results. Eighteen patients were hospitalized and underwent bronchoscopy and biopsy. One of these patients had Stage I non small cell lung carcinoma (NSCLC) and a lobectomy was performed. Three patients had Stage IV NSCLC and were referred for chemotherapy. We identified 103 semi-positive results. Only 25 of those patients had a repeat scan because of noncompliance. We observed no significant growth of diagnosed nodules in a semi-positive group. Low-dose CT can be used as a screening tool for early stage lung cancer. A high percentage of false-positive results are observed. There are difficulties in diagnosing nodules in patients with post-tuberculosis changes. A high rate of noncompliance was noticed.