Key points:
  1. This article is the first one to study the survival rate of different degrees of carotid artery invaded by nasopharyngeal carcinoma.
  2. The incidence of fatal bleeding after radiotherapy was only 2.3% (3/130).
  3. The circumference of tumor attachment to the artery and the disappearance of fat gaps were utilized to estimate the extent of carotid artery invasion , which was classified into three subtypes according to the involvement grade before therapy.
  4. In LANC patients whose carotid artery invasion was <270º, helical tomotherapy combined with concurrent chemotherapy and EGFR inhibitor after induction chemotherapy had mild and tolerable side effects, better PFS and DMFS, with no massive hemorrhage.
  5. In patients whose primary tumor was pharyngeal recess with carotid artery invasion ≥270º, diabetes with poor control or re-radiotherapy led to a higher risk of massive hemorrhage after radiotherapy.