X-rays are fine, how can low-dose CT detect pulmonary nodules? 2 out of 3 people will have it after the age of 50

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Mr. Zhang was just 50 years old and often coughed. He went for a physical examination a while ago and underwent a low-dose CT (LDCT) under the doctor’s recommendation. The result was that there were two nodules in the lungs, which made him very worried. It is related to the habit of smoking for a long time. After understanding Mr. Zhang’s situation, the doctor believes that the nodules in his lungs should not be tumors. It may be related to the previous lung disease, but Mr. Zhang may have chronic lung inflammation due to long-term smoking. To quit the habit of smoking, otherwise the risk of developing lung cancer in the future is still very high.

Now that lung cancer has become a malignant tumor with a high incidence in China, what does it have to do with pneumonia and pulmonary fibrosis? If the chest X-ray for physical examination in the past is normal, is there no need to worry about the tumor? So what is low-dose CT?

What is the relationship between pneumonia and lung cancer?

First of all, pneumonia and lung cancer are two different diseases. Long-term chronic inflammation in the lungs can easily lead to cancer, and lung adenocarcinoma accounts for more than 70% of lung cancers.

Pneumonia is inflammation of the lungs, and there are two types, acute and chronic. Acute pneumonia is usually caused by microbial infections, including bacterial, fungal or viral infections. This type of pneumonia deteriorates rapidly and has a high fatality rate, because after the pathogenic bacteria or viruses invade the human body, it will cause a large number of lung cells in a short period of time. Damage, the loss of lung function, people can not carry out gas exchange, and finally lead to systemic organ hypoxia and necrosis.

There is also chronic pneumonia, some of which are transformed from acute pneumonia; there are also long-term smokers who inhale harmful gases and carcinogens. progressed to lung cancer.

Lung cancer is a mutation in the cells. Cancer occurs when cells in the body mutate. Cells are damaged by carcinogens for a long time, which may one day cause cell gene mutation and then become cancer. It will not happen suddenly, but will be affected by long-term adverse effects, which may be exogenous or endogenous factors, gradually. Change into cancer cells and eventually form tumors.

Statistics show that long-term chronic inflammation of the lungs is one of the important factors causing lung cancer, so there is a causal relationship between pneumonia and lung cancer.

There is one lung adenocarcinoma in lung cancer, which is currently the type of lung cancer with the highest proportion and the largest number of patients. The number of people with lung adenocarcinoma accounts for about 7-80% of the total number of lung cancers. In addition, another feature of lung adenocarcinoma is that there is no obvious correlation between the cause and smoking, especially in women.

Many people know that patients with liver disease have a trilogy of “hepatitis → liver fibrosis → liver cancer”, but the same is true for patients with pneumonia.

When the lung is in a state of chronic inflammation, long-term exposure to inflammatory environmental damage will leave scars, which is the so-called fibrosis. If the fibrosis is deeper, it is irreversible. Accumulation of scars for a long time, more, not only affect lung function, but also may become cancer.

In addition, lung cancer is also like liver cancer. Not every patient will go through the process of fibrosis, and it may jump directly from chronic inflammation to cancer. Just like many lung adenocarcinoma patients whose lungs look good, but cancer grows inside, It’s really not easy to prevent.

If the chest X-ray is normal, there is no need to worry about lung cancer? wrong! Low-dose CT for early detection

Many people think that a chest X-ray can reveal various abnormalities in the chest cavity. Therefore, there are a lot of clinical cases where people have just had a chest X-ray and the examination is normal, but they are found to have lung cancer.

X-ray examination, although the radiation is low, convenient and cheap, but two-dimensional plane imaging, even if it is taken from the front and side, but there are still many dead spots, on the one hand, small tumors cannot be seen, on the other hand, because of the chest and abdomen. Many organs overlap , and if the tumor is on the side or behind of an organ, it is not easy to find, which may be missed.

Generally speaking, only 70% of the area that can be seen clearly is only 70% when the X-ray is thrown away from the dead angle. This is a very fatal problem. Sometimes the tumor may be 4-5 cm in size at the location of the dead angle, but it still cannot be found. It misses a good opportunity for treatment, and it is also prone to medical disputes.

In recent years, many medical institutions have begun to use low-dose CT to screen lung cancer, and X-ray films are more used for other diseases. Studies abroad have found that regular low-dose CT screening in high-risk groups can increase the 5-year survival rate by 20% and the 10-year survival rate by 26%.

Low-dose CT can detect lung cancer about 5 to 10 years earlier, and early detection has a higher survival rate

The most important key to combating lung cancer is early detection. Low-dose CT of the lungs can detect lung cancer about 5-10 years earlier than chest X-rays . few.

According to statistics, if it can be detected early, the 5-year survival rate of first-stage lung cancer can be as high as 90%, and the second-stage lung cancer has more than 60%, and there is even a chance to cure it. But 2 years.

Therefore, I would like to remind everyone not to mistakenly think that the chest X-ray examination is fine and you can feel at ease. People with a history of smoking or high risk of lung cancer in their immediate family should have a low-dose CT examination as soon as possible. To the extent that treatment may not be very effective, not only suffer from the pain, but the survival rate is also very low.

What should I do if a pulmonary nodule is detected? Different situations are handled differently

When abnormal images appear in lung examination, those larger than 3cm are called masses, and those smaller than 3cm are called pulmonary nodules, which usually appear as white or gray dotted shadows on X-rays.

Generally speaking, two-thirds of people over the age of 50 will find pulmonary nodules , and the older they are, the higher the probability of finding them, even if they find 20 or 30 at a time.

This is actually very similar to what grows on human skin. There are few or no things when you are young, but it will increase with age, but not necessarily all problems, but must be further based on the size and shape of the nodule. Only by judgment can we know whether it is malignant tumor, benign tumor, infection and inflammation, or scars or calcifications left after pneumonia or tuberculosis in the past.

Nodules are divided into two types: solid and non-solid. The former is a very white spot on X-ray or CT. Small solid nodules tend to be scars left after inflammation has recovered. Large ones are more likely to be Lung cancer; the latter has a ground glass shape, also known as ground glass pulmonary nodules. Ground-glass pulmonary nodules have an 80-90% risk of cancer , but they are still in the early stage of cancer and have not metastasized. Of course, they may be just severe inflammation or scarring, and biopsy is generally required for pathological confirmation.

Whether solid or non-solid pulmonary nodules are clinically used as the basis for subsequent treatment according to their size and characteristics. However, it is very professional to make treatment opinions due to the characteristics of nodules. Here, only the size of the nodules is used to make a difference, so that everyone can easily understand:

1. The nodule is less than 0.5 cm

Treatment principle: follow-up observation, do low-dose CT every 6 months to one year.

2. Nodule 0.5-0.8 cm

Treatment principle: Low-dose CT follow-up examination is performed every 3-6 months. If the nodules become larger, or the proportion of solid nodules in non-solid nodules increases, further biopsy or surgery is required. If there is no change, continue follow-up examination.

3. Nodules greater than 0.8 cm

Treatment principle: There is a risk of growth or metastasis, and it is necessary to consult a doctor as soon as possible. According to the situation, it is determined by surgical resection or biopsy.

Generally speaking, most pulmonary nodules smaller than 0.8 cm are not lung cancer , so don’t be afraid if you find a nodule during the physical examination, and first observe the changes through follow-up examination.

If the nodule becomes smaller or disappears after a period of time, then it can be determined that it is just inflammation or scars left after pneumonia infection; if the nodule becomes larger and more obvious, it is necessary to consider whether there is a possibility of malignancy .

But even so, at this stage of pulmonary nodules, most of them belong to the early stage of the disease, and there is still time for relevant treatment, and there is a good chance of curing it with the follow-up observation or treatment of doctors.

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