Pericarditis

Delayed chronic pericarditis appears several weeks to years after radiotherapy. In this type, extensive fibrous thickening, adhesions, chronic constriction and chronic pericardial effusion can be observed. It is observed in up to 20% of patients within 2 years following irradiation.

Constrictive pericarditis can be observed in 4–20% of patients and appears to be dose dependent and related to the presence of pericardial effusion in the delayed acute phase.

Cardiomyopathy

Diffuse myocardial fibrosis (often after a >30 Gy radiation dose) with relevant systolic and diastolic dysfunction, conduction disturbance and autonomic dysfunction.

Restrictive cardiomyopathy represents an advanced stage of myocardial damage due to fibrosis with severe diastolic dysfunction and signs and symptoms of heart failure.

Valve disease

• Valve apparatus and leaflet thickening, fibrosis, shortening, and calcification predominant on left-sided valves (related to pressure difference between the left and the right side of the heart).
• Valve regurgitation more commonly encountered than stenosis.
• Stenotic lesions more commonly involving the aortic valve.
• Reported incidence of clinically significant valve disease: 1% at 10 years; 5% at 15 years; 6% at 20 years after radiation exposure.
• Valve disease incidence increases significantly after >20 years following irradiation: mild AR up to 45%, ≥ moderate AR up to 15%, AS up to 16%, mild MR up to 48%, mild PR up to 12%.

Coronary Artery Disease (CAD)

• Accelerated CAD appearing in the young age.
• Concomitant atherosclerotic risk factors further enhance development of CAD.
• Latent until at least 10 years after exposure (patients younger than 50 years tend to develop CAD in the first decade after treatment, while older patients have longer latency periods).
• Coronary ostia and proximal segments are typically involved.
• CAD doubles the risk of death; relative risk of death from fatal myocardial infarction varies from 2.2 to 8.8.

Carotid artery disease: Radiotherapy induced lesions are more extensive, involving longer segments and atypical areas of carotid segments. Estimated incidence (including subclavian artery stenosis) about 7.4% in Hodgkin’s lymphoma.

Other vascular disease: Calcification of the ascending aorta and aortic arch (porcelain aorta). Lesions of any other vascular segments present within the radiation field.