Chest X-rays are an effective method to assess your lungs and heart. It is often considered when a patient complains of symptoms like chest pain, shortness of breath, and persistent cough. Often incidentally, medical professionals detect small, abnormal growths in the lungs, which might cause some worry. These are also known as lung nodules. In an interaction with the OnlyMyHealth team, Dr Shriram Shenoy, Consultant Pulmonologist, Manipal Hospital, Kharadi, explains ways to interpret, assess, and monitor lung nodules.
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What Are Lung Nodules?
“Lung nodules are tiny growths in the lung tissue that are round or oval in shape and generally have a diameter of less than three centimetres,” describes Dr Shenoy, adding that they tend to be found by chance during a chest X-ray or CT scan that is done for unrelated purposes.
According to a 2022 study published in the JAMA, lung, or pulmonary, nodules are identified in approximately 10.6 lakh people per year in the US and are detected on about 30% of chest CT scans.
The majority of lung nodules don't cause any symptoms and could indicate either benign or cancerous.
While a chest X-ray gives a first look, a CT scan gives a more comprehensive assessment that helps identify the nodule's size, form, and features.
To differentiate benign nodules from those that need more assessment, additional imaging or follow-up procedures are sometimes required. Further treatment is influenced by variables such as the nodule's appearance, smoking status, and patient history.
Can Lung Nodules Be Cancerous?
Most lung nodules are benign and are caused by inflammation, infections, or non-cancerous growths like hamartomas or granulomas. According to Dr Shenoy, the percentage of malignant lung nodules is lower, and those who have a history of smoking, exposure to chemicals, or a family history of lung cancer are at higher risk.
Size, form, and growth rate are some of the variables that affect the chance of malignancy. While larger or irregularly shaped nodules need closer examination, nodules smaller than 6 mm have a lower chance of being malignant. The type of nodule and the necessity of additional treatment are ascertained with the aid of follow-up imaging and other testing.
Follow-Up Tests To Assess Lung Nodules
While most lung nodules are harmless and benign, it is always advised to assess them and keep them under close observation.
Multiple types of additional tests are usually used to evaluate lung nodules based on their size, appearance, and risk factors. “To evaluate changes over time, high-resolution CT scans offer thorough imaging. PET scans can be used to evaluate metabolic activity, particularly in nodules that are bigger or appear suspicious. Before any invasive operation, pulmonary function testing aids in determining lung capacity,” says Dr Shenoy.
He adds, “When cancer is suspected, a biopsy may be done for histological study using bronchoscopy, needle aspiration, or surgical excision. In certain situations, molecular profiling and blood testing are employed. Regular imaging follow-up over several months or years helps in tracking the development of nodules.”
When Is A Biopsy Required?
According to the doctor, monitoring of solitary lung nodules is often guided by the Fleischner Society pulmonary nodule recommendations. The Fleischner Society Guidelines provide recommendations for managing incidental pulmonary nodules detected on CT scans in adults less than or equal to 35 years old.
"After six to twelve months, follow-up imaging is often required for low-risk individuals with small nodules (less than 6 mm). Repeat CT scans may be required more frequently for larger nodules or those with questionable characteristics. If a nodule exhibits strong metabolic activity on a PET scan, has uneven or spiculated boundaries, or shows considerable growth, a biopsy is required. Patients with a high-risk profile or those who exhibit symptoms are also advised to undergo invasive testing. A multidisciplinary team approach ensures the best possible diagnosis and treatment choices,” shared Dr Shenoy in detail.
Conclusion
Lung nodules are usually harmless; however, it is always necessary to monitor them. Size, growth pattern, and related risk factors are some of the variables that affect when lung nodules need to be monitored, says Dr Shenoy. For more information or clarification, it is best to consult a doctor and understand individual risk and circumstances