Accelerated carotid artery disease after high-dose head and neck radiotherapy: is there a role for routine carotid duplex surveillance?

PURPOSE

High-dose external radiotherapy used in the treatment of head and neck carcinoma has been implicated as a risk factor for accelerated atherosclerotic disease of the carotid arteries. However, how radiotherapy affects atherosclerotic disease is controversial, and little data exist to demonstrate a strong relationship between radiotherapy and progressive carotid disease.

METHODS

We performed a retrospective chart review of 69 patients (all men) who underwent duplex ultrasound scanning examinations for carotid disease between 1993 and 1998. Twenty-three patients had received high-dose radiotherapy for the treatment of head and neck carcinoma within the past 12 years (group 1; mean age, 67.8 years), and 46 patients were randomly selected as age-matched control subjects (group 2; mean age, 68.3 years). The mean radiation dose was 6060 +/- 182 rads, and the average interval between radiotherapy and ultrasound scanning was 6. 5 +/- 1.8 years. There was no significant difference between the two groups in the presence of these comorbidities: diabetes mellitus, coronary artery disease, hypertension, tobacco use, hypercholesterolemia, peripheral vascular disease, or stroke. Similarly, there was no difference in the indications for the duplex scanning studies.

RESULTS

Five of the 23 patients in group 1 (21. 7%) were found to have advanced carotid disease (70% to 99% stenosis); four patients were symptomatic, three patients went on to endarterectomy, and one patient was awaiting surgery. Two of the 46 patients in the control group (4%) had advanced carotid disease. One patient was symptomatic, and both patients underwent endarterectomy. A significant difference in the prevalence of advanced disease between the two groups was noted (P =.037). Sixteen patients who survived irradiation underwent a second duplex scanning study and had evidence of progressive disease with significant increases in peak systolic velocities.

CONCLUSION

High-dose radiotherapy to the head and neck region may be a significant risk factor for accelerated carotid atherosclerotic disease. Routine carotid duplex surveillance may be warranted in this high-risk patient population.