Radiation therapy to the mediastinum may be complicated by acquired valvular disease. The risk of valve disease has declined as radiation therapy has improved.
Mediastinal radiation may be given for lymphoma, breast cancer, lung cancer or mediastinal tumor.
The valves most often affected are:
(1) tricuspid valve
(2) mitral valve
(3) aortic valve
Risk factors for valve damage:
(1) high radiation dose
(2) concurrent chemotherapy
(3) increased time since radiation therapy
(4) pre-existing valve disease (mitral valve prolapse, congenital, rheumatic, other)
Valvular damage may take the form of:
(1) fibrosis
(2) calcification
(3) thickening
(4) incomplete closure with regurgitation
Comorbid therapy-induced complications which may affect valve repair may include:
(1) coronary arterial stenosis
(2) pericarditis
(3) cardiomyopathy
(4) mediastinal fibrosis
(5) myocardial fibrosis
(6) endocardial fibrosis
