Radiation pericarditis
Introduction
Introduction to radioactive pericarditis Radiation pericarditis (radiation pericarditis) is caused by radiation damage of the heart and pericardium, often a complication of radiotherapy for breast and mediastinal malignancies, such as breast cancer, Hodgkin's disease and non-Hodgkin's lymphoma. basic knowledge The proportion of illness: 0.0025% Susceptible people: no special people Mode of infection: non-infectious Complications: constrictive pericarditis, aortic regurgitation, atrioventricular block, pericardial effusion
Cause
Causes of radiation pericarditis
(1) Causes of the disease
Radioactive pericarditis is a serious complication of breast cancer, Hodgkin's disease and non-Hodgkin's lymphoma radiation therapy. The damage of myocardial and pericardium by radiotherapy depends on:
1 dose of radiation therapy;
2 treatment times and treatment time;
3 the volume of the heart included in the radiation treatment area;
Compared with the linear accelerator, 460Cobalt (60Co) has an uneven distribution of 60Co irradiation.
(two) pathogenesis
1. 60% of the heart shadow in the radiation therapy of Hodgkin's disease in the irradiation field, after 4 weeks dose less than 40Gy (4000rad) treatment, the incidence of radiation pericarditis is about 5% to 7%, more than this dose of radioactive pericarditis Ascending, when the entire pericardium is exposed to the irradiation field, the incidence of pericarditis is 20%. If the heart is protected with a protective pad under the protuberance, the incidence can be reduced to 2.5%.
2. Breast cancer radiation therapy, the heart volume in the irradiation field is less than 30%, can tolerate more than 6 weeks, 60Gy (6000rad) treatment, the incidence of radioactive pericarditis is less than 5%.
It is currently believed that radioactive pericarditis occurs many years after radiation therapy, and the clinical manifestations are chronic pericardial effusion or constrictive pericarditis.
3. The pathological changes of radioactive pericarditis are fibrin deposition and pericardial fibrosis. In the acute inflammation stage, pericardial effusion can be serous, serous or bloody, protein and lymphocyte components increase, and initial inflammatory reactive exudate can naturally Regression, if thick fibrin exudate continues to increase, so that pericardial adhesion, pericardial thickening and pericardial small blood vessel proliferation will form chronic exudative pericardial effusion, constrictive pericarditis and radiotherapy often caused by exudation - Constrictive pericarditis.
Radiation therapy can sometimes damage the myocardium, cause myocardial interstitial fibrosis, valve thickening, aortic regurgitation, aortitis, varying degrees of atrioventricular block, thickening of myocardial small arterial fibrosis, may be associated with endocardium Fibrosis or elastic fiber hyperplasia, myocardial fibrosis, can also develop into restrictive cardiomyopathy, coexisting with constrictive pericarditis after radiotherapy.
Prevention
Radioactive pericarditis prevention
In the course of radiotherapy for breast cancer, Hodgkin's disease and non-Hodgkin's lymphoma, attention should be paid to the dose, frequency and time of radiotherapy. The dose should not be too large, and the time should not be too long. The volume of the heart should be as small as possible. In the process of radiotherapy, attention should be paid to the protection of the heart and lungs. If necessary, protect the heart with a protective pad under the bulge, which can reduce the damage to the heart.
Complication
Radioactive pericarditis complications Complications, constrictive pericarditis, aortic valve regurgitation, atrioventricular block, pericardial effusion
Often combined with radiation myocardial damage, chronic pericardial tamponade and constrictive pericarditis.
1. Radioactive myocardial damage radiotherapy sometimes damages the myocardium, causing myocardial interstitial fibrosis, thickening of the valve, aortic regurgitation, aortitis, varying degrees of atrioventricular block, thickening of myocardial small arterial fibrosis, Can be associated with endocardial fibrosis or elastic fiber hyperplasia, myocardial fibrosis, can also develop into restrictive cardiomyopathy.
2. About 50% of patients with chronic pericardial tamponade have chronic massive pericardial effusion, with varying degrees of cardiac tamponade.
3. The clinical manifestations of pericardial constriction may occur in elderly patients with constrictive pericarditis.
Symptom
Radioactive pericarditis symptoms common symptoms pericardial effusion electrocardiogram abnormal pleural effusion anorexia pericardial constriction
A few manifestations of acute pericarditis symptoms, fever, precordial pain, anorexia, general malaise, pericardial friction and electrocardiogram abnormalities, delayed pericarditis often 4 months to 20 years after radiation therapy, most commonly within 12 months Acute non-specific pericarditis or asymptomatic pericardial effusion and pleural effusion appear gradually disappear in a few months or years. About 50% of patients have chronic massive pericardial effusion with varying degrees of cardiac tamponade. Clinical manifestations of pericardial constriction may occur.
Examine
Radioactive pericarditis
Electrocardiogram examination: ST-T changes, there may be varying degrees of atrioventricular block.
Diagnosis
Diagnostic identification of radioactive pericarditis
diagnosis
Clinical diagnosis can be established if there is a malignant tumor and radiotherapy is performed to produce pericarditis or pericardial effusion.
Differential diagnosis
Radioactive pericarditis is often confused with pericarditis caused by the original malignant tumor. Pericarditis of tumor metastasis or infiltration is often a large number of pericardial effusion, cardiac tamponade, pericardial effusion cytology, 85% of cases can determine the primary Stove, if Hodgkin's disease is clinically cured after several years of pericarditis, the symptoms of pericardial effusion still exist, radiation damage is more likely than malignant tumor metastasis, radiation therapy can induce hypothyroidism, and pericardial effusion occurs. The rate is about 25%, and the pericarditis caused by viral infection needs to be differentiated from radioactive pericarditis.
