Background: Radiation is the treatment of choice for numerous head and neck tumors, including nasopharyngeal carcinomas. There is, however, underreporting of long-term effect of radiotherapy in large vessels, in particular carotid arteries, which are always included in the radiation port.
Case reports: We are presenting 5 patients (aged 52–68 years, mean age of 61.4) with history of nasopharyngeal carcinoma who received radiotherapy and developed carotid stenosis afterwards. The stenosis was severe enough
to cause neurological symptoms and signs. The carotid artery stenosis was diagnosed by different imaging modalities including conventional angiography, color Doppler ultrasound and magnetic resonance imaging. All these imaging techniques can provide useful information about the degree of stenosis and the extent of involvement.
Conclusions: The clinical significance of carotid artery stenosis as a long-term complication of radiotherapy to head and neck tumors could not be overemphasized. Non-invasive imaging such as color Doppler and magnetic
resonance imaging allow serial examinations and should be employed for the assessment of the condition.

Keywords: carotid stenosis, Radiotherapy