Assessing nodules detected in lung cancer screening: the value of positron emission tomography.

Lung cancer is the leading cause of death worldwide. Screening for lung cancer may improve the poor prognosis by detecting the cancer at an early stage where radical surgery still is possible. Several randomised clinical trials using low-dose computed tomography (CT) have been launched in high-risk smokers or former smokers in the USA and Europe [1–3]. The National Lung Screening Trial (NLST) randomised 53454 subjects to undergo annual CT scans or chest radiographies for 3 years, and demonstrated that overall and lung cancer specific mortality was reduced in the CT arm [1]. For one case of death from lung cancer to be prevented, the number of patients that needed to be screened using CT compared with chest radiography was 320 [3]. The final mortality data testing of >32000 individuals participating in the seven European randomised lung cancer CT screening trials (EUCT), where the control groups had no chest radiography, is expected in 2015 [2].