In radiation therapy for thoracic tumors, lung tissue often receives a certain dose of irradiation, causing radiation damage to normal lung tissue. The complications arising from contraction of lung injury-acute radiation pneumonia and pulmonary fibrosis-are the dose-limiting factors in radiation therapy for thoracic tumors.
Radiation pneumonia usually occurs 1-3 months after radiation therapy. In patients who undergo radiation therapy after chemotherapy, radiation pneumonia can often occur during or near the end of radiation therapy. Patients who undergo chemotherapy after radiation therapy can also experience a “recall effect” during chemotherapy, which can trigger the onset of pneumonia.
Radiological lung injury RTOG classification criteria.
Acute
Grade 0: No change.
Grade 1: Mild dry cough or dyspnea on exertion.
Grade 2: persistent cough requiring narcotic cough suppressants/ dyspnea with slight activity, but no dyspnea at rest.
Grade 3: Severe cough, ineffective to narcotic cough suppressants, or dyspnea at rest/clinical or imaging evidence of acute radiation pneumonia/intermittent oxygen or possible need for steroid therapy.
Grade 4: Severe respiratory insufficiency/continuous oxygen or assisted ventilation therapy.
Grade 5: Fatal.
Late stage lung injury
Grade 1: Asymptomatic or mild dry cough, mild radiological changes.
Grade 2: Moderately symptomatic pulmonary fibrosis or pneumonia, low-grade fever, lamellar radiological changes
Grade 3: severe pulmonary fibrosis or pneumonia with dense radiological changes
Grade 4: Severe respiratory dysfunction with continuous oxygen-assisted ventilation
Grade 5: Death.
Treatment of radiation pneumonia
During radiation therapy, patients should be closely observed for respiratory symptoms and elevated body temperature. If pneumonia is found, radiation therapy should be stopped immediately. Patients should inform the physician in charge promptly if they feel that the present cough and sputum symptoms are aggravated or if they originally have no cough and sputum symptoms, and then cough and sputum symptoms appear. Early exudation stage, treatment is effective, and after fibrosis, treatment is poor.
Treatment mainly consists of symptomatic treatment of.
1, the application of adrenal glucocorticoids, commonly used prednisone, according to the symptoms, determine the amount of prednisone, if the symptoms are mild, can choose oral medication, and gradually reduce the amount after the symptoms disappear. If the symptoms are obvious, intravenous high-dose shock therapy is required, and then it is changed to oral after the symptoms are reduced. Remember, some patients think that the symptoms disappear and glucocorticoids have side effects, so they do not follow the doctor’s advice and stop the medication privately, resulting in rebound, missing the best treatment period and poor treatment effect.
2.If respiratory difficulty occurs, give oxygen, expectorant and bronchodilator to improve respiratory difficulty.
3.If combined with infection, apply antibiotics.