Annual or biennial lung cancer CT screening?

Annual low-dose computed tomography (LDCT) screening has been found to be an efficient lung cancer screening program for a high-risk population (1). According to the United States guidelines annual screening is recommended for high-risk individuals, defined as those aged 55–74 years, with a 30 pack-year smoking history and who currently smoke or have quit within the past 15 years. This is based on the results of the National Lung Screening Trial (NLST), which provided an insight into how to decrease death due to lung cancer (1). NLST was a randomized trial comparing annual screening by LDCT with chest radiograph for three years in 53.454 high-risk persons at 33 United States medical centers. The trial showed that lung cancer screening with LDCT can reduce lung cancer mortality by 20% compared to chest X-ray for current or former heavy smokers (1).