[Aortic regurgitation developed seven years after mediastinal radiation therapy: report of a case].

We report on radiation-induced valvular dysfunction in a 41-year-old woman who developed aortic regurgitation with clinical symptoms, requiring aortic valve replacement seven years after mediastinal radiation therapy for carcinoma of the breast. She was treated with cobalt radiation therapy of 4000 rads to her left mediastinum. The excised three-cuspid aortic valve was edematous and densely fibrotic without commissural fusion. Histological examination strongly suggested that the aortic valve with diffuse fibrosis, destruction of elastic fibers and bizarre nucleus in fibroblasts had been induced by mediastinal radiation therapy. To our knowledge, symptomatic radiation-induced valvular dysfunction in the aortic position has been reported infrequently, with only eleven reported cases. In this case, symptomatic aortic regurgitation was diagnosed seven years after mediastinal radiation therapy. It is emphasized that long-term follow-up is important for patients receiving mediastinal radiation therapy.