Ultrasound assessments of carotid artery intima-media thickness (IMT) have potential to serve as an early marker for carotid artery disease (CAD) associated with radiation therapy in patients with head and neck cancer (HNC). These findings from a study of the literature were reported in the Journal of the Advanced Practitioner in Oncology.
“Critical vascular structures, including the carotid artery, are often within the radiation treatment field due to their proximity to cervical chain lymph nodes, a common site of metastasis,” the researchers conducting this review explained in their report. Ultrasound-based measurement of carotid artery IMT is an approach to assessing CAD risk in certain patient populations, and the researchers set out to investigate evidence on its use as an early marker of CAD in adults with HNC who have undergone radiation to the neck.
The researchers reviewed literature identified through PubMed and Scopus database searches with publication dates from January 2011 through December 2020. Articles were identified for inclusion based on relevant keyword searches and the use of relevant treatment approaches.
The review included 8 articles, of which 4 involved prospective studies and 4 involved retrospective studies. Across these reports, following neck radiation, carotid IMT demonstrated significant increases. Increases in carotid artery IMT also appeared to occur relatively early after radiation therapy and were persistent.
The researchers considered ultrasound to be suitable for detection of alterations in carotid IMT after radiation. The approach appeared able to identify pathologic IMT levels indicative of higher future risk, acting as a possible early marker for radiation-associated CAD.
The timing of ultrasound evaluations after radiation therapy varied widely across the studies. One study obtained ultrasound measurements on the last day of radiation, which was 6 weeks after treatments had begun, and significant carotid IMT increases had already been detectable at this time. Another study, which obtained ultrasound measurements across several time periods, suggested ultrasound screening should begin at 1 year following treatment. Another study suggested the presence or absence of plaques should be a determinant in the timing of ultrasound evaluations. Some studies showed mixed results regarding the timing of evaluation.
“Clinicians providing care to HNC patients should consider obtaining baseline carotid ultrasound with IMT measurements prior to the start of neck radiation and at 1 year post therapy,” the researchers wrote in their review. They also concluded that an increase in carotid IMT observed through ultrasound measurement may serve as a surrogate end point for carotid artery stenosis and risk of future stroke after radiation therapy in adults with HNC.
Randolph W, Dains JE. Ultrasound evaluation of carotid artery intima-media thickness: effective early marker of carotid artery disease in adult head and neck cancer patients after neck radiation? J Adv Pract Oncol. 2022;13(7):683-694. doi:10.6004/jadpro.2022.13.7.4