Background: In the course of radiation therapy of malignant tumors, inclusion of major arteries into the radiation field is often inevitable.
Patients and methods: Clinical case reports and studies were compiled and analyzed with respect to the effect of irradiation on the risk of arteriosclerotic changes within the radiation field. The study concentrates on those anatomic locations which are involved frequently enough in order to allow a quantitative analysis.
Results: In a series of clinical studies, a consistent 3- to 4-fold increase in carotis stenoses is observed following radiation therapy of head and neck tumors. The majority of clinically symptomatic stenoses, however, is not observed earlier than 8 years post irradiation. Although observations in other peripheral arteries do not allow to estimate incidences, they do confirm, however, the finding of a very long latent time. Following mediastinal or thoracic wall irradiation, the risk of coronary artery disease is significantly increased after follow-up times of > or = 10 years. Radiation related arterial injury is sharply limited to arterial segments included in the treatment field and is often observed in unusual locations. The histological appearance and development however, is not fundamentally different from lesions observed in cases of generalized arteriosclerosis. Experimental observations indicate that patients with general arteriosclerosis risk factors might have a particularly increased risk of developing arterial injury following therapeutic irradiation.
Conclusion: Irradiation of large blood vessels in the course of tumor therapy represents a long-term local risk factor for development of arteriosclerosis.