Lung nodules that have been reviewed for five years without change still need to be reviewed regularly, and a chest CT once a year, which indicates that the nodules are very likely to be benign. If a lung nodule has not changed for more than two years, it is generally considered to be benign. Lung nodules should be reviewed regularly according to the risk factors of lung cancer. If you have smoked for more than 20 years and are exposed to a pack of cigarettes per day, occupational exposure to dust, chemical fumes, haze or have a family history of lung tumors or other tumors, these are all high risk factors of lung cancer and you still need to review chest CT regularly.