In recent years, with the widespread use of low-dose chest CT in health check-ups, lung nodules have become a frequent term in health reports. In outpatient clinics, doctors often encounter patients clutching CT reports with anxious faces. "Doctor, is my nodule cancerous? Should I have surgery immediately?" Some even demand immediate removal out of fear of cancer. However, others dismiss it as "just a few millimeters" and, upon follow-up years later, are found to have advanced lung cancer.

In fact, the vast majority of lung nodules are benign, but a small number may be early-stage lung cancer. How to achieve a scientific balance between "over-treatment" and "delayed diagnosis and treatment"? This is precisely the core of the "precision assessment + standardized follow-up" concept advocated by modern respiratory medicine.

A lung nodule refers to a focal shadow with a diameter of ≤3 cm, clear boundaries, increased density, and surrounded by normal lung tissue. Due to the widespread use of low-dose CT, the detection rate of lung nodules in the general healthy population has been increasing. This is particularly common in individuals over 40, with a history of smoking or exposure to air pollution. It must be clarified that "high detection rate does not equal high cancer rate." Studies show that the malignant probability of solid nodules smaller than 6 mm is less than 1%.

Judging the nature of a lung nodule cannot be based solely on one CT scan; it requires a comprehensive assessment of multiple factors. Both the "Chinese Expert Consensus on the Diagnosis and Treatment of Lung Nodules (2024 Edition)" and international guidelines emphasize that for most lung nodules, the preferred strategy is regular CT follow-up rather than immediate biopsy or surgery. For solid nodules smaller than 6 mm, routine follow-up is not necessary; for solid nodules measuring 6–8 mm, a follow-up every 6–12 months is required, and if stable, another check-up every 18–24 months; if the nodule is larger than 8 mm or has high-risk factors such as smoking or a family history, further evaluation with PET-CT, biopsy, or bronchoscopy may be considered. For pure ground-glass nodules smaller than 10 mm, annual follow-up is recommended for 5 years; if it is a mixed ground-glass nodule, the follow-up frequency is determined based on its composition and size.

If a lung nodule is detected during an examination, do not panic first, as more than 95% of lung nodules are benign or indolent lesions; however, do not ignore it, especially for larger nodules or those with high-risk factors, it is essential to follow the doctor's advice for follow-up!