Introduction
Lung surgeries treat various medical conditions, including cancer, COPD (chronic obstructive pulmonary disease - a group of lung diseases narrowing the airway and making it difficult to breathe), emphysema (air sacs in the lungs are damaged resulting in shortness of breath), lung infections, cysts (a cavity filled with a liquid or semi-solid substance that may or may not cause pain), and tumors. The surgery will depend on the condition and severity of the medical condition. Surgery may be used to remove tissues, remove tumors, repair damage, or restore breathing. Frequent surveillance of the lungs after lung surgery is important to ensure that the patient is healing properly and that the surgery was successful. It also allows doctors to monitor the patient for any potential complication that may occur after surgery, such as an infection, pneumonia (fluid-filled lungs), or fluid buildup inside the lungs. Additionally, frequent surveillance may allow physicians to adjust medications or treatments to prevent future complications. As a result, frequent surveillance is essential for ensuring that the patient fully recovers from lung surgery. This article will discuss surgeries performed to remove tumors from the lung and the impact of frequent surveillance after the surgery.
What Are the Different Types of Lung Surgeries?
A variety of medical conditions affecting the lungs need medical and surgical attention. Few surgeries of the lungs are
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Lobectomy is the surgical resection of a lung lobe to remove a tumor or treat a severe infection.
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Pneumonectomy is the surgical resection of an entire lung to remove a tumor or treat a severe infection.
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Bronchoplasty is a procedure to reconstruct or repair a diseased and damaged airway.
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Thoracoscopic surgery (VATS) is a minimally invasive technique to diagnose and treat various lung diseases.
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Pleurodesis is a surgical procedure to seal off the room between the two layers of the pleura, which is the tissue that lines outside the lungs.
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Lung Volume Reduction Surgery is a surgical procedure to remove the damaged portions of the lung to reduce the total amount of lung tissue in the chest cavity.
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A lung transplant is the transplantation of a healthy lung from a donor to a patient with a failing lung.
What Is the Importance of Surveillance After Surgical Resection of Lung Cancer?
Surgical resection of the affected portion of the lung is the main treatment option for non-small-cell lung cancer (NSCLC - cancer cells form in the tissue of the lungs), with a high five-year survival rate of 90 %. Despite the successful surgical correction, non-small-cell lung cancer (NSCLC) remained one of the leading causes of cancer deaths worldwide because of its high recurrence rate. It increases susceptibility to developing new primary lung tumors.
Recent studies suggest that early and frequent surveillance after lung surgeries yields better outcomes since many patients can be identified with a new or recurrent cancer early and can be treated with a higher survival rate. Advances in surveillance technologies like computed tomography (CT- an imaging technique to create a detailed picture of the areas inside the body) and chest X-rays have raised the chances of tumor detection during surveillance tests. They have subsequently increased the chances of survival for this group of people.
What Is the Rationale for Frequent Surveillance After the Surgical Correction?
Patients who have undergone surgical treatment for stage one non-small-cell lung cancer (NSCLC) are at high risk of developing the following three events:
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Development of New Primary Metachronous Non-small-Cell Lung Cancer (NSCLC): 27 % of the patients treated for stage one of NSCLC are at risk of developing new primary cancer, with the highest occurrence in the first 24 to 36 months after the resective surgery. The national lung screening trial through studies has shown that screening through low-dose computed tomography (LDCT- CT scanning at a dose of 1.5 millisieverts) has helped in very early detection and increasing the survival rate of people at high risk of lung cancer. Since the study excluded cancer survivors, the data from the study is extrapolated to apply to lung cancer survivors.
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Intrathoracic Recurrence of Primary Cancer: Though theoretically rare, the recurrence of primary cancer at the resection margins has an incidence of seven to 27 %. The highest risk is seen in cases like the inadequate sampling of lymph nodes, residual microscopic disease (cancer cells left after treatment) at the resection margins, and sub-lobar resection (removing a small section of the lungs).
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Distant Metastasis: Metastasis to distant organs like the brain, bone, liver, and adrenal glands is rare, but cases have been reported. However, surveillance to detect asymptomatic metastasis is not recommended because distant metastasis is incurable and can be treated only when they become symptomatic.
What Are the Methods of Surveillance?
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Chest X-Rays: Chest X-ray was the most common mode of lung surveillance post-surgery in the past decade. However, it has very poor sensitivity in detecting the new primary metachronous lung cancer ( a new tumor developing after a cancer-free interval of four years or more) (NPMLC) or the intrathoracic recurrence after the surgery. It was still being used because of the lack of alternative surveillance technologies. Now it is largely abandoned as a surveillance model for lung cancer survivors. In the era of advanced technologies like CT (computed tomography), scanning chest X-rays has a very limited role and is not used as the sole modality for surveillance after resectioning non-small-cell lung cancer.
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Low-Dose Computed Tomography (LDCT): Low-dose computed tomography works at a radiation dose of 1.5 mSV (millisievert); they are highly sensitive for detecting primary parenchymal nodules (a small tissue within a gland carrying the function of the gland) in the lung but are less sensitive for detecting mediastinal (part of the chest between the sternum, spinal cord and between the lungs) and nodal abnormalities compared to the standard dose computed tomography. Studies have shown that low-dose computed tomography is an effective tool for lung cancer detection. Recently several institutions have been using LDCT for surveillance after lung cancer resection surgeries. Many studies are being carried out to determine the optimal time intervals between LDCT follow-ups and to identify the advantages of LDCT for low-risk patients. Intense trials are ongoing currently to evaluate whether the use of surveillance tools will increase the rate of detection of recurrent and new cases.
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Standard Dose Computed Tomography (SDCT): The American association for thoracic surgery and the national comprehensive cancer network recommend standard dose computed tomography (SDCT) as the most important mode of cancer surveillance after resective lung surgery. SDCT delivers an effective radiation dose of eight mSV (millisievert). The high dose of radiation and a contrast enhancement enables excellent imaging of the lung parenchyma (a large number of thin-walled alveoli for gas exchange) and the structures in the mediastinum. Recent studies on SDCT have shown that surveillance with SDCT after a resective lung surgery (a surgical procedure to remove all or part of the lungs) for stage one non-small-cell lung cancer has resulted in an early diagnosis of the subsequent new primary metachronous lung cancer (NPMLC) when compared to chest X-ray. However, it did not directly affect the survival rates.
Conclusion
To conclude, compelling evidence suggests frequent post-surgical surveillance with computed tomography (CT) scanning techniques after the resection of stage one non-small-cell lung cancer is worthwhile. It results in the early detection of new primary metachronous lung cancer and intrathoracic recurrence of primary cancer. With early detection and appropriate treatment, stage one NSCLC survivors have a higher incidence of survival after five years.
