DETECTION OF RADIATION-INDUCED, ACCELERATED ATHEROSCLEROSIS IN PATIENTS WITH OSTEORADIONECROSIS BY PANORAMIC RADIOGRAPHY

Purpose: Osteoradionecrosis (ORN) of the mandible has long been consid ered the most destructive complication of head and neck irradiation. R ecently, therapeutic irradiation has been implicated as the cause of i nduced/accelerated atherosclerosis of the cervical carotid artery and subsequent stroke. Panoramic radiography, previously shown to be capab le of identifying carotid artery atherosclerosis in nonirradiated indi viduals, was used to assess the carotid vasculature of patients being treated for ORN. Patients and Methods: The panoramic radiographs of 61 men (mean age, 60.5 years; range, 41 to 77 years) who received therap eutic irradiation to the neck 36 months or more previously were assess ed for the presence of carotid artery atherosclerotic lesions. Sixty-o ne control subjects who never received therapeutic irradiation, but wh o were similarly susceptible to atherosclerosis by virtue of age, were assessed in a like manner. Results: The irradiated individuals sustai ned a dose of 40 to 72 Gy to the area of the carotid bifurcation. Seve nteen individuals (27.9%) with an irradiation dosage to the carotid bi furcation that averaged 59.2 Gy had a panoramic radiograph with a caro tid atheroma (11 with unilateral lesions and six with bilateral lesion s). The radiographs of the control subjects showed that three individu als (4.9%) had calcified carotid lesions. The mean age of these subjec ts was 66.1 years; two had unilateral lesions, and one had bilateral l esions. The difference in the proportion of individuals with ORN who m anifested carotid artery atherosclerosis on their panoramic radiograph s was statistically significant (P = .001) when compared with the noni rradiated control subjects. The lesions seen in both populations had a similar morphologic appearance and were radiographically located with in the soft tissues of the neck 1.5 to 4.0 cm inferior-posterior to th e angle of the mandible. Conclusions: Individuals with radiation doses sufficient to cause osteoradionecrosis of the mandible are at signifi cantly higher risk of developing carotid artery atherosclerotic lesion s than age-matched, nonirradiated controls.