What Is Pneumomediastinum?

Radiation pneumonia is an inflammatory response caused by damage to normal lung tissue in the radiation field after radiation treatment of lung cancer, breast cancer, esophageal cancer, malignant lymphoma or other malignant tumors of the chest. The mild ones are asymptomatic and the inflammation can dissipate on their own; the severe ones have extensive fibrosis in the lungs, leading to impaired respiratory function and even respiratory failure.

Basic Information

Visiting department

Respiratory Medicine

Common locations

lung

Common causes

Pneumonia, bronchitis, chronic bronchitis, chronic obstructive pulmonary disease, and re-radiation therapy, etc.

Common symptoms

Irritating, dry cough with shortness of breath, palpitations and chest pain

Causes of radiation pneumonia

The occurrence and severity of radiation pneumonia are closely related to the radiation method, radiation volume, radiation area and radiation velocity. The larger the radiation field, the higher the incidence rate; large area radiation of lung tissue damage is more serious than local radiation, the faster the irradiation rate, the more likely to produce lung damage. Other influencing factors such as the poor tolerance of individuals to radiation, the original lung lesions such as pneumonia, bronchitis, chronic bronchitis, chronic obstructive pulmonary disease, and re-radiation therapy are easy to promote the occurrence of radiation pneumonia. Certain chemotherapeutic drugs may also aggravate the radiation therapy response in the lungs. Elderly and children have poor tolerance to radiation therapy.

Clinical manifestations of radiation pneumonia

Patients with mild symptoms are asymptomatic, more than 2 to 3 weeks after radiation therapy, and often have irritation, dry cough, shortness of breath, palpitations, and chest pain, without fever or low fever, and occasionally high fever. Shortness of breath as lung fibrosis worsens progressively, prone to respiratory infections and aggravate respiratory symptoms. Difficulty swallowing with concurrent radiation esophagitis. If the ribs are damaged by radiation, rib fractures occur, and local tenderness is noticeable. Physical examination showed that the skin of the radiation site atrophied and hardened, and dry, wet snoring and friction sounds were heard in the lungs. Extensive and severe fibrosis of the lungs eventually leads to pulmonary hypertension and pulmonary heart disease with corresponding signs.

Radiation pneumonia test

Change in lung function

Pulmonary radiation pneumonitis and fibrosis both cause restrictive ventilatory dysfunction, reduced lung compliance, reduced ventilation / blood flow ratio, and reduced diffuse function, leading to hypoxia. Sometimes chest radiographs have not been found abnormal, and pulmonary function tests have shown changes.

2. X-ray performance

Most of the lungs become shadowed one month after stopping radiation therapy. In the acute stage, a migraine-like fuzzy shadow appears on the irradiated lung field, and a reticular shadow is faintly seen during this period, which is exactly like bronchial pneumonia or pulmonary edema. The extent of the lesion is consistent with the field of thoracic surface irradiation. Pulmonary fibrosis occurs chronically, with a cord-like or mass-like contraction or local atelectasis. The mediastinum pleura and pericardium have a large amount of adhesion, the mediastinum is displaced to the affected side, the ipsilateral diaphragm is elevated, and the thorax is collapsed.

Radiation pneumonia diagnosis

To make a correct diagnosis, a comprehensive analysis must be performed based on the exposure history, exposure dose, clinical manifestations, laboratory examinations, and auxiliary examinations such as x-rays to exclude lung diseases caused by other factors.

Differential diagnosis of radiation pneumonia

Acute radiation pneumonia should be distinguished from the following diseases. The main point is to make a comprehensive judgment based on the etiology, medical history, clinical manifestations, and multiple examinations.

Non-radioactive pneumonia

Including mycoplasma pneumoniae pneumonia, pneumococcal pneumonia, staphylococcus pneumonia, Klebsiella pneumonia, and some drug-induced interstitial pneumonia caused by some anticancer drugs such as bleomycin.

2. Tuberculosis

3. Lung tumor

Includes primary bronchial lung cancer and lung metastatic tumors.

Radiation pneumonia treatment

To prevent the occurrence of radiation pneumonitis, the total radiation dose, its single dose allocation, and the size of the irradiation field should be strictly grasped. Radiation therapy for breast cancer is best done with tangential projection to avoid lung damage. During radiotherapy, patients should be closely observed for respiratory symptoms and elevated body temperature. X-ray examination revealed pneumonia, and radiation therapy should be stopped immediately. The treatment is mainly symptomatic, and antibiotics are given for secondary infections of the lungs. Early application of glucocorticoids is effective and is generally treated with prednisone. Anticoagulant therapy is not effective in treating small vessel embolism. Oxygen inhalation can improve hypoxemia.