Probability of lung cancer based on the size threshold and volume-doubling time for lung nodules detected in low-dose CT screening

Hyun Lee, Sang-Won Um


Lung cancer accounts for about 1.6 million deaths per year worldwide (1). Most patients are diagnosed with advanced disease, resulting in a very low 5-year survival rate. Screening with low-dose computed tomography (LDCT) has reduced the mortality from lung cancer by 20% (2). However, the main challenge with LDCT screening for lung cancer is the high prevalence of false-positive results and the relatively low incidence of lung cancer (3). The implementation of LDCT screening in public health requires validated guidelines to determine the optimum patient management strategies based on the characteristics of lung nodules. From this perspective, the size threshold is important because it determines which nodules need an immediate diagnostic work-up and those that do not need follow-up. Moreover, a validated protocol is needed to manage intermediate nodules because individuals with these nodules need subsequent follow-up, which has some risk of radiation exposure.