Diagnosis of lung cancer
Diagnosis of lung cancer
Diagnosis of lung cancer, If you are looking for a doctor because of certain symptoms , he or she will first ask you in detail about your symptoms and lifestyle and assess your general health. They should be open and honest, because by means of the most accurate information the doctor can limit a presumption or even better rule out certain diseases. If the suspicion of lung cancer exists, he initiates the necessary investigations. It can then be clarified whether the tumor is indeed a tumor, and if so, what type of tumor is present and how far the disease has progressed. The most common investigations in cases of lung cancer include:
How can you diagnose lung cancer?
- laboratory tests
- The bronchoscopy
- Computed tomography (CT) of the chest
- Ultrasound of the thoracic and ventral spaces
If lung cancer is actually detected, further investigations are carried out. They are primarily intended to show how far the tumor has spread, whether lymph nodes are infected and whether secondary tumors (metastases) have formed in other body regions. These examination methods, depending on the stage, include:
- Investigations such as, Such as pulmonary function testing or stress examinations, are intended to illustrate the functional integrity of the lungs. Endobronchial ultrasound (EBUS)
- Ultrasound examination (sonography)
- Computer tomography (CT) of the abdomen
- Magnetic resonance tomography (MRI) of the skull
- PET-CT (combined examination of positron emission tomography and computed tomography) on the question of operability or distant metastases
- Skeletal scintigraphy (= bone scintigraphy)
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At first, the doctor inquires about complaints and possible risk factors (anamnesis) and conducts a physical examination. In this way he can already gain important information about the nature of the disease.
Blood tests provide information about the general condition of the patient as well as the functions of individual organs such as kidneys, liver and bone marrow.
An investigation on tumormarkers is usually not carried out in case of suspicion of lung cancer, since its meaningfulness is too inaccurate.
Radiographs of the lungs
One of the most important diagnostic procedures is the X-ray examination of the chest. From a size of about half a centimeter in diameter, tumors are visible on the radiograph.
Above all in the lung periphery lying tumors can be identified well with this method, whereas centrally located in the lung are more badly in the x-ray image visible or demarcable.
If there is a suspicion of lung cancer, bronchial mirroring (bronchoscopy) belongs to the standard examination methods. With the bronchoscope, an optical device, the bronchi can be directly viewed. The patient is introduced a flexible tube, which is a few millimeters thick, through the nose or mouth into the air tube and further into the bronchial tubes. In this way, the physician can take out the smallest tissue samples or mucosal smears from the bronchial tubes and the lung tissue, which are subsequently examined in the laboratory for cancer cells (cytologic or histological examination by the pathologist). Only through the examination of a tissue sample can it be decided whether it is actually cancer. The type of tumor can also be determined by this.
If no cancer cells are found, this does not necessarily mean that none are present. However, in the case of bronchoscopically attainable tumors, more than 70% of the investigations lead to a correct diagnosis.
As a rule, the patient receives a calming agent before bronchoscopy. Subsequently, the doctor numbles the mucous membranes in the nasopharynx, larynx, and large bronchi with a local anesthetic. It may be that the examination triggers a slight pressure or coughing sensation, pain usually does not occur. In addition to the flexible tube, there is also a rigid bronchoscope, which is used, for example, when a tumor which directs the airways (bronchial tubes) For example, must be removed by laser in order to keep the airways open. The examination with this bronchoscope is always carried out in general anesthesia.
Computer tomography (CT) – controlled puncture
If bronchoscopy could not be used to obtain meaningful tissue samples, Eg because the suspicious area is not reachable within the lung due to its peripheral position and surgery is not possible, a CT-assisted puncture can be carried out from the outside. A long, thin hollow needle is advanced through the thoracic wall into the suspect region under computer tomography control, and some tissue is suctioned off. The skin is locally anesthetized, so that this examination can be performed as painless as possible.
Small, or poorly demarcated tumors in the lungs can be tracked with the aid of computed tomography (CT). Tumors with a size of 0.3 centimeters can be visualized with this method. CT is indispensable in the case of unclear X-ray findings and the exact determination of tumor spread, but CT can not reliably distinguish between benign and malignant findings. This examination method is a special X-ray method by means of which the body is transilluminated layer by layer. It provides information about the extent of the tumor in the area of the lungs and the surrounding lymph nodes and its relationship to adjacent organs and tissue structures. In patients with a lung carcinoma, computed tomography is particularly useful to detect metastases in the head, chest and abdomen areas. The physician receives important information about whether the tumor can be surgically removed, whether or not vital organs are already affected by the disease, and how extensive the operation will be.
Magnetic resonance tomography (MRI)
Magnetic resonance tomography (also MRI) is helpful in locating metastases in the brain, spinal cord and skeleton. The method employs a strong magnetic field and radii waves in order to produce sectional images of specific areas of the body, similar to CT images. The patient is not exposed to X-rays. Certain questions, such as the spread of the lung tumor into the thoracic wall or into large vessels or the detection of brain metastases, can often be assessed better with this method than with computer tomography. However, due to the higher resolution (greater accuracy) CT is still the standard method for the imaging diagnostics of tumors in the lung tissue.
Video-assisted thoracoscopy (VATS – Reflection of the thoracic cavity)
Also the video-assisted thoracoscopy (VATS) allows the assessment of the lung and a sampling of tissue samples. For this purpose, a small special camera is introduced via small incisions in the thoracic cavity, the images of which the doctor can see on a monitor (“keyhole surgery”). This investigation is particularly useful when fluid is present in the chest (a pleural effusion), but the investigation of cells from this effusion has not been a diagnosis. The VATS is also the method of choice for the clarification of suspicious findings (unclear “pulmonary center of the lung”), which can not be reached bronchoscopically or only with difficulty. These flocks are usually found in the periphery of the lungs or in the ridge. The VATS can be performed under local or general anesthesia.
Ultrasound examination (sonography)
With the help of the ultrasound examination of the abdomen, the doctor can determine whether the tumor has already spread to other organs (metastasis). In particular the liver, but also kidneys, adrenal glands, spleen and lymph nodes are examined for metastases. The ultrasound examination of the heart can provide information about the performance of the heart muscle. This is crucial for the choice of the treatment method. Frequently – by regular smoking – not only the lungs are damaged, but the heart can be reduced due to a constriction of the coronary arteries (heart muscle weakness). This can affect the OP’s ability or choice of chemotherapy.
A fluid accumulation in the thoracic cavity (= pleural effusion) can also be assessed by means of ultrasound. Ultrasound control also involves punctures of the lungs and other abdominal organs (after appropriate local anesthesia). Ultrasonic examination without puncture is painless. It can be repeated as often as possible because it does not expose the patient to any harmful radiation exposure.
Skeletal scintigraphy (bone scintigraphy)
The skeletal scintigraphy shows whether the tumor has already affected the bones (bone metastases). For this purpose, small amounts of a radioactive substance are added to the blood stream, which predominantly accumulates in bone tumors (‘daughter tumors’). A camera that records this radioactive radiation in the bone can thus detect tumor suspicious areas. The examination is not painful and the radiation rapidly decays.
Positron Emission Tomography (PET)
In positron emission tomography , radioactively labeled sugar components are added to the blood stream, thus depicting the metabolism of the sugar in the body. Tumors and metastases show an increased metabolic activity in contrast to healthy tissue and thereby cancel themselves out of the healthy tissue in PET imaging.
With PET, the whole body (with the exception of the brain) can be examined for the presence of metastases. The abnormalities observed in the PET can, however, have been caused not only by cancer, but also by inflammation or benign lymph node diseases such as sarcoidosis. The latter findings, however, usually only store a small amount of radioactivity. Therefore, a further evaluation of the PET findings by means of a tissue sampling is often necessary. The PET is often performed simultaneously with a CT scan of the entire body combined. The combination of the two methods of examination (PET-CT) leads to a better anatomical classification of the findings and, if necessary, serves the further, purposeful clarification by EBUS or mediastinoscopy.
Endobronchial ultrasound (EBUS)
Lung carcinomas often spread over the lymphatics. The lymph nodes of the mediastinum, ie, the space between the two pulmonary arteries, are particularly frequently affected. If the choice of therapy depends on the most reliable information about the condition of these lymph nodes, a tissue sampling from these lymph nodes should be performed. The EBUS offers the possibility to find lymph nodes and tumors located under the mucous membrane during bronchoscopy while simultaneously performing a tissue puncture.
Bronchoscopy is combined with ultrasound. At the end of the bronchoscope used, an ultrasound head is located, through which the lymph nodes in the mediastinum can be visualized and punctured. The procedure is anesthetized.
If a clear clarification of suspicious lymph nodes in the intermediate skin is not achieved by bronchoscopy and EBUS, a mediastinoscopy can be useful. In this case, a small incision is made under full anesthesia directly above the sternum, through which an optical probe is introduced into the space between the pulmonary arteries. Suspicious lymph node parts or the complete removal of all mediastinoscopically reachable lymph nodes (VAMLA) can be performed by the tubular device and then examined for cancer cells.
Pulmonary function test
The pulmonary function tests, before and after inhalation of bronchodilators and circulatory function tests (spiroergometry), provide information on the functional condition of the lung and are particularly important with regard to a planned operation. Frequently, there is a COPD or other disease-limiting disease pattern at the time of diagnosis. Thus, for example, For example, whether there is sufficient functional pulmonary tissue left when a lung flap or a whole lung wing has to be removed to completely remove the tumor. Due to the increasing age of the patients and the following limitation of the pulmonary function, it is also possible to selectively remove smaller sections of the lung (segmentctomy), if removal of larger sections would result in inoperability. The proper functioning of the lung must also be taken into account when planning the irradiation of a lung tumor.