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Compelling evidence from several sources now suggests that in high-risk individuals, CT (computed tomography or CAT) screening is the best method to detect lung cancer in its earliest stage. The majority of lung cancers originate as a small growth or nodule in the lung. Screening CT scans are extremely sensitive in detecting nodules as small as 2 or 3 mm within the lungs—much smaller than can be viewed on a conventional chest x-ray. In fact, recently published articles on CT screening found that the majority of lung cancers revealed on CT scanning could not be detected on a chest x-ray that was performed simultaneously.
PET (positron emission tomography) is a powerful, non-invasive, diagnostic tool that detects biochemical changes in body tissues. To feed their rapid growth, tumors consume more glucose than healthy tissues. The PET scanner, which creates a color-coded image of the body's chemical function, reveals the cancer as red "hot spots" of activity.
PET/CT is the combination of PET and CT imaging techniques within a single machine. The individual PET and CT scans are taken concurrently while the patient remains in place, and can be presented separately or as a single, overlapping, "fused" image.
The two techniques present different types of information about the human body. While PET shows chemical activity, CT shows anatomical structures. For example, a PET scan would highlight a tumor's increased glucose consumption, while a CT scan would reveal its physical mass. The fused PET/CT image provides a more reliable alternative to the traditional side-by-side visual comparison of PET and CT images.
The tests and procedures that may be ordered by your doctor for diagnosis of lung cancer include:
- Sputum cytology: A sample of phlegm (mucus you cough up from your lungs) is checked to see if cancer cells are present.
- Chest x-ray: an x-ray of the organs and bones inside your chest.
- Bronchoscopy: a procedure to look inside your trachea and large airways of your lung to check for abnormal areas. A bronchoscope (a thin, lighted tube) is passed through your mouth into your trachea and lungs. Tissue samples can then be taken for biopsy.
- Electromagnetic navigational bronchoscopy: This procedure uses a bronchoscope (a thin, lighted tube) with global positioning system (GPS)-like technology to create a three-dimensional picture of your lungs. This allows your pulmonologist or surgeon to steer a set of catheters through your lungs to reach the area that is abnormal on computed tomography (CT) scan. Once it is reached, tiny biopsy tools are passed through the scope and tissue samples are then obtained.
- Endobronchial ultrasound (EBUS): Ultrasound uses sound waves to make pictures of parts of your body. For endobronchial ultrasound, a bronchoscope (a thin, lighted tube) is fitted with an ultrasound device at its tip and is passed down into your windpipe. If areas of concern are seen on ultrasound (such as enlarged lymph nodes), a hollow needle can be passed through the bronchoscope and guided by ultrasound into the area to take tissue samples. The samples are then looked at under a microscope to see if cancer cells are present.
- Needle aspiration: a needle is inserted through your chest and into the tumor to remove a sample of tissue to be tested.
- Thoracentesis: fluid is removed from the pleural cavity (space between your lungs and chest wall) through a needle inserted between the ribs.
- Thoracoscopy: a thin, lighted tube connected to a video camera is used to view the space between the lungs and the chest wall. This allows doctors to see tumors on the surface of the lungs. The doctor can also take a biopsy of any suspicious areas or remove protions of the lung.
- Thoracotomy: a surgery to open your chest and obtain a biopsy or remove portions of the lung.
Tests available for lung cancer include:
- state-of-the-art imaging for non-invasive diagnostics, staging, and
pre-surgical evaluations including, CT, CT-PET, bone scan, and
- diagnostic and biopsy procedures, such as fine needle aspiration biopsy,
core needle biopsy, thoracentesis, pleural biopsy, and image guided
CT scans with low dose radiation can detect lung cancer when it is very small. Fine needle aspirations (FNAs) sample a lung tumor without the need to open the chest.
This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.