Cardiac disease after mediastinal irradiation for seminoma.

One hundred twenty-four patients with seminoma (119 primary testis, five primary extragonadal) were treated between 1968 and 1984 at the Joint Center for Radiation Therapy. Fifty-seven of the 124 patients were treated with irradiation to the mediastinum as well as to an infradiaphragmatic field. One patient received supradiaphragmatic radiotherapy only. The remaining patients had radiation treatment limited to the infradiaphragmatic field only. Median dose to the mediastinum among the 58 patients was 2400 cGy. Four patients developed heart disease (one fatal myocardial infarction, one uncomplicated myocardial infarction, one constrictive pericarditis resulting in permanent total body anasarca, and one patient requiring aortic valve replacement and coronary artery bypass grafting for atherosclerotic disease) and two died suddenly. The two sudden deaths were thought to be cardiac in origin by the patient's primary physicians. All six complications occurred in the group that received mediastinal irradiation. No cardiac disease was manifested in the group not treated with mediastinal irradiation. This difference in the incidence of cardiac disease between the two groups is statistically significant (two sided, P = 0.019). Neither group had a statistically significant difference in cardiac disease rate from a normal population (Framingham study), although the ratio of observed to expected cardiac disease was 1.97 in the group receiving mediastinal radiation. Further experience from this and other institutions is necessary to confirm this finding.