Type of Studies Reviewed. The authors conducted a MEDLINE search for 1997 through 2002 using the key terms "radiation therapy," "carotid artery" "atherosclerosis," "cancer" and "dentistry." The articles selected for further review included those published in English in peer-reviewed journals, with preference given to articles reporting randomized, controlled trials.

Results. Recent advances in the delivery of radiation therapy to malignancies of the head and neck have resulted in the prolonged survival of increasing numbers of patients. However, the therapy has been implicated as causing atherosclerotic lesions in the cervical component of the carotid artery, which predisposes patients to an increased risk of developing stroke. Panoramic radiography can identify some of these lesions before they can cause a stroke. Radiation-induced atherosclerosis is common, with approximately 40 percent of patients developing hemodynamically significant carotid artery plaques within 10 years of having received irradiation.

Clinical Implications. Dentists treating patients who have received therapeutic radiation to the neck should examine the patients’ panoramic radiographs for evidence of atheromalike calcifications, which appear 1.5 to 2.5 centimeters posterior and inferior to the angle of the mandible. Patients with evidence of such lesions should be referred to their physician for an ultrasound examination of their carotid arteries.