Among all apparatuses of human body lungs are one of the most fundamental components, which involves in the respiratory system. It helps the respiratory process, which is critical for human body. No doubt, among all lung diseases, lung cancer has a severe effect on one’s physical condition. We know that cancer is a severe disease all over the world which is caused due to irregular and uninhibited cell division. Lung cancer may be classified assuming the form of lung cancer cells, i.e. small cell lung cancer (oat cell carcinoma) and non small cell lung cancer (adenocarcinoma). 
In an early stage of lung cancer, it does not show any symptom that is why it is very difficult to diagnose. Lung cancer is diagnosed both by physical examination and different tests such as imaging tests such as X-ray, CT scan and MRI scans, Positron Emission Tomography (PET), sputum cytology, biopsy. Bone scan, fine-needle aspiration biopsy. Among this PET scan is very effective for diagnose. It shows images of cell greater details than X-ray.
Lung is involved to exchange gases between the blood and the air we inhale. In this process, carbon dioxide is released from the bloodstream, and oxygen enters the bloodstream. Lung cancer is one of the most important causes of death due to cancer in both men and women all over the world. Factor affecting behind this disease, smoking is vital. However, people that are exposure to the smoking area are at higher risk of lung cancer. Tobacco smoke contains of more than 4000 chemicals which all are harmful to lung cell. Due to constant exposure of smoking, lung cell starts to damage and in turn cancer develops. Cancer cell moves to other parts of the body through numerous numbers of blood vessels and lymph vessels.
PET means “Positron Emission Tomography and it is an investigative step which provides a complete illustration of the deviation. It is also a sign as to whether it is malignant or not. According to the medical science, abnormal cancer cell requires a huge nutrition which they take in the form of sugar. Cancer tumors exhibit high rates of metabolic activity that is why they use a lot of energy. In this process first into the patient body glucose solution is injected, which is laced with a slightly radioactive sign. Then concentrated glucose solution is being highlighted by the process of PET scan, which provides an outline of the level of the deviation and as the lungs are typically air (which has no metabolism), it provides a specific position of the tumor. However, it kept in mind that a positive result may not be a definite indication of cancer because the high metabolic activity can occur by other conditions such as swelling of lung tissues, which will exhibit on the PET scan. Lung biopsies, biological analysis of lung sputum and viewing the lungs with bronchoscopy are also used for the determination of cancer cells.
During a PET scan, a doctor will inject a radioactive substance into the patient’s body. The radioactive material that is injected into the patient’s body during PET scans to be able to capture with a particular camera that makes 3D images. The metabolic process occurs inside the body is demonstrated through this image. Areas with significant activity recommend the existence of cancerous tumors. It is very effective for a patient who is suffering from primary stage lunge cancer. To determine the spread of cancer cell to the lymph nodes it is used frequently. PET scans are also helpful for doctor to find out the area where the cancer has to multiply regularly.
PET scans can scan overall body, so they are used sometimes instead of X-ray. Similarly, in bone scans a radioactive material (usually technetium diphosphonate) is injected through the vein. The radioactive material made up in bone areas implicit in having cancer metastasis, (spread). This small amount of radioactive materials is used in this process have no any long-term effects. Bone scans are usually applied on patients with small cell lung cancer and also in non small cell lung cancer patients when the doctor can prove the cancer has spread, which is examined by other symptoms. To determine properly where the chemical activity is going on inside the cell the PET scans result are combined with CT scan.
The treatment of the lung cancer is mainly depending on the stage of the cancer and many other criteria such as overall health and type of cancer cell. Chemotherapy is normally given to the patients but targeted drug therapy, and radiation therapy may be given. At present, in lung cancer treatment surgery is the use, but it is very sensitive. It is helpful for taking remedial steps when it is diagnosed at primary stage. PET scan is very expensive. Chemotherapy, radiation therapy, or targeted therapies possibly will be used for destroying the cancer affected cells. Family members should be sympathetic and lend their expressive maintain.