What tests should be done if lung cancer is suspected

If there is reason to suspect that you have lung cancer, your doctor will use one or more tests to confirm the diagnosis of lung cancer. If these tests have found lung cancer, more tests should be done to find out how far the cancer has spread. We will be exposed to many tests during our medical treatment and treatment. Here are some of the common methods used in the diagnosis of lung cancer.

1. Imaging diagnostic methods for lung cancer:

1. X-ray diagnosis: It is the most commonly used method for diagnosing lung cancer, including fluoroscopy, plain film, tomography, chest computer-assisted tomography (CT), magnetic resonance imaging (MRI), bronchography, etc. The principle in clinical practice is to perform examinations in the order of the above arrangement from simple to complex, from low cost to high cost.

The X-ray manifestations of early lung cancer are: a. Solitary spherical shadows or irregular small pieces of infiltration; b. Localized emphysema during the expiratory phase; c. Mediastinal swing during deep breathing; d. If lung cancer progresses to block the segmental or lobar bronchus, the gas at the distal end of the blockage is gradually absorbed and segmental atelectasis occurs. If this atelectasis is complicated by infection, pneumonia or lung abscess will form. In addition to more clearly observing the shape, density, location, hilar and mediastinal lymphadenopathy of the tumor, ordinary tomographic films can also understand the blockage, stenosis, external pressure, and tumors in the larger bronchi (above the lung segment).

2. Magnetic resonance imaging (MRI): It is an imaging diagnostic technology newer than CT. It can more clearly show the relationship between the central tumor and the blood vessels of the surrounding organs in the diagnosis and periodicity of lung cancer. It does not require contrast agents and can determine whether the tumor has invaded the blood vessels or compressed the surrounding blood vessels. If it exceeds 1/2 of the circumference, it will be difficult to remove. If it exceeds 3/4 of the circumference, no surgical examination is required. MRI can also clearly show when the tumor invades the soft tissue.

3. Bone imaging or emission computed tomography (ECT): It can detect lesions 3-6 months earlier than ordinary X-rays, so bone imaging can detect bone metastases earlier.

4. Positron emission tomography (PET): Whole-body positron emission tomography (PET) can detect unexpected extrathoracic metastases. There is no false positive rate in cases of extrathoracic metastasis, but PET examinations can have false positive findings in mediastinal granulomas or other inflammatory lymphadenopathy. These cases need to be confirmed by cytology or biopsy. However, there is no doubt that PET can make preoperative lung cancer diagnosis more accurate.

2. Fiberscope examination:

1. Fiberoptic bronchoscopy: The positive detection rate is much better than that of rigid bronchoscopy because the image is magnified by optical fiber illumination. During the examination, attention should be paid to the vocal cord mobility, the shape and mobility of the bulge, and the changes of the bronchial orifices at all levels (generally up to 4-5 levels) such as tumors, stenosis, ulcers, etc., and brush cytology, bite biopsy, local lavage, etc. should be performed. If a suspected carcinoid tumor is found to have abundant blood supply, it should be performed with caution, and it is best to avoid biopsy trauma.

2. Percutaneous lung puncture: It is suitable for peripheral lesions and is not suitable for thoracotomy for various reasons. It is mostly used in internal medicine. At present, it tends to use fine needles, which are safer to operate and have fewer complications.

3. Mediastinoscopy: There is a consensus that mediastinoscopy should be performed when CT scan shows enlarged lymph nodes in groups 2, 4, and 7, such as the anterior and lateral tracheal lymph nodes and the subcarinal lymph nodes.