Detection of radiation-induced cervical atheromas by panoramic radiography.

Therapeutic irradiation of the neck is frequently used to treat patients with head and neck carcinoma. The irradiation, however, has been implicated as the cause of cervical carotid artery atherosclerotic lesions and subsequent stroke. Panoramic radiography previously shown capable of demonstrating isolated lesions was used to assess their development over time. Individuals with a pre-irradiation radiograph free of atheromas were enrolled for study. The prevalence rate of atheroma formation on post-irradiation (bilateral portals at >/=45 Gy) radiographs obtained at an interval of >/=36 months was determined. A control group of non-irradiated patients having similar risk factors for head and neck carcinoma and atherosclerosis and having an initial radiograph free of atheroma formation were likewise enrolled for study. The prevalence rate of atheroma formation on a second radiograph obtained from these individuals at an interval of >/=36 months was determined. The study population consisted of 17 patients, with a mean age of 56.5 (range 21.5-77.8) years who received a mean therapeutic irradiation dose of 53.2 Gy (range 45-71) to each side of their neck. The prevalence rate of atheromas manifested on the post-irradiation radiographs was 53%. These radiographs were obtained, on average, 69.7 (range 37-133) months after completion of radiation therapy. The prevalence rate of atheromas manifested on the second radiograph of patients in the control group was 5.9%. These radiographs were obtained, on average, 53.5 (range 52-55) months after the first. The difference in prevalence rates was statistically significant (p=0.0003). Individuals who have received therapeutic irradiation to the neck are more likely to develop carotid artery atheromas after treatment than are risk-matched control patients who have not been irradiated. These lesions can be detected by panoramic radiography.