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Carotid artery stenosis (CAS) is a known potential late effect of neck radiation. There are varying estimates of its incidence and mixed consensus on whether screening for this late effect standard practice should be. As treatment techniques have evolved and the presence of HPV has increased, the impact on the future trajectory of this problem is unclear. A sample of head and neck cancer (HNC) patients treated from 1997 through 2022 who underwent carotid ultrasound (US) at any time after receiving radiation therapy to the neck were identified from an IRB-approved, single institution database. Patient treatment characteristics including radiation laterality, co-morbidities at consult, and smoking history were coded in addition to carotid US dates and results. CAS was defined as >40% stenosis of either side of the vessel, which prompted a vascular surgery consult. A total of 308 patients were included in this study with an average follow up of 70 months (range: 3.3-255.9 months). All included patients received bilateral neck radiation and had no evidence of disease at their last follow up. Most patients received definitive, concurrent chemoradiation (96.4%), were male (85.1%) and had a primary oropharyngeal tumor (64%). The most common co-morbidity at time of consult was hypertension (HTN, 45.8%). Median time to CAS was 10.7 years. The five- and ten-year rates of CAS were 15.4% and 39.6%, respectively. On Cox regression univariate analysis age at consult (HR=1.054, 95% CI= 0.649-1.941, p<0.001), having known HTN (HR=2.551, 95% CI=1.610-4.032, p<0.0001), hyperlipidemia (HR=1.658, 95% CI= 1.066-2.584, p=0.0248), diabetes (HR=2.398, 95% CI=1.397-4.115, p=0.0015), or cardiac disease (HR=2.283, 95% CI=1.333-3.922, p=0.0026) at time of consult, and being an ever smoker (HR=2.336, 95% CI=1.403-3.891, p=0.0011) were statistically predictive of CAS. On multivariate analysis, patients who were older (HR=1.037, 95% CI=1.008-1.068, p=0.0122), were an ever smoker (HR=2.375, 95% CI=1.425-3.968, p=0.0009), and having known hypertension (HR=2.037, 95% CI=1.235-3.356, 0.0053) at consult were at highest risk for CAS. CAS was frequently detected five and ten years after head and neck radiation. Carotid artery US screening should be strongly considered in these patients, especially older patients with a history of smoking and/or HTN. Future prospective studies are warranted to verify this finding. [ABSTRACT FROM AUTHOR]

Carotid artery stenosis (CAS) is a known potential late effect of neck radiation. There are varying estimates of its incidence and mixed consensus on whether screening for this late effect should be standard practice. As patients are being treated at younger ages and living longer, especially in the HPV era, this question is becoming increasingly important. Head and neck cancer (HNC) patients treated from 1997 through 2020 who underwent carotid ultrasound (US) at any time after receiving radiation therapy to the neck were identified from an IRB-approved, single institution database. The primary outcome for this study was clinically significant CAS, defined as >50% stenosis in any carotid artery in the radiation field. Framingham risk score (FRS) was also calculated for each patient based on risk factors present at the time of consultation to determine 10-year risk of developing cardiovascular disease (CVD). The FRS takes gender, smoking, blood pressure control, and cholesterol into consideration to determine cardiovascular risk. Patient treatment characteristics including radiation laterality, co-morbidities, and smoking history were also coded. Kaplan Meier analysis was used to estimate the rates of CAS. Logistic regression analysis was used to identify factors associated with CAS. A total 79 patients were included in this initial analysis with the median follow up of 5.1 years. Most patients had definitive, concurrent chemoradiation (96.2%), were male (79.7%), and received bilateral neck radiation (89.9%). A FRS was able to be calculated for 53 patients at time of consult with a majority of patients having either an intermediate (41.5%) or high (49.1%) risk of developing CVD disease in 10 years. The most common co-morbidity at time of treatment was hypertension (50.6%). Overall, 28 patients (35.4%) were found to have CAS based on US results. The two- and five-year rates of CAS were 7% and 20%, respectively. On Cox regression univariate analysis, only the presence of having a co-morbidity of hypertension was statistically predictive of CAS (HR=2.51, 95% CI= 1.12-5.62, p=0.0251). Age, FRS, smoking status at time of treatment, and bilateral vs unilateral radiation were not associated with an increased risk of CAS. Clinically significant CAS increases with time with increasing duration of follow up. Patients with baseline hypertension appear to be at higher risk and should be more strongly considered for screening. Longer follow up is needed to correlate CAS with adverse outcomes and quantify longer term risks (e.g. 10-20 years post treatment) in this highly curable population. [ABSTRACT FROM AUTHOR]