RESUMO
BACKGROUND: Carotid blowout syndrome (CBS) is a rupture of the carotid artery and is mainly caused by radiation and resection of head and neck cancers or direct tumor invasion of the carotid artery wall. It is a life-threatening clinical situation. There is no established and effective mode of management of CBS. Furthermore, there is no established preceding sign or symptom; therefore, preventive efforts are not clinically meaningful. CASE SUMMARY: We described two cases of CBS that occurred in patients with head and neck cancer after definitive chemoradiotherapy (CRT) using three-dimensional conformal intensity-modulated radiation therapy. Two men aged 61 and 56 years with locally advanced head and neck cancer were treated with definitive CRT. After completing CRT, both of them achieved complete remission. Subsequently, they had persistent severe pain in the oropharyngeal mucosal region and the irradiated neck despite the use of opioid analgesics and rehabilitation for relief of contracted skin. However, continuous follow-up imaging studies showed no evidence of cancer recurrence. Eleven to twelve months after completing CRT, the patients visited the emergency room complaining about massive oronasal bleeding. Angiograms showed rupture of carotid artery pseudoaneurysms on the irradiated side. Despite attempting to secure hemostasis with carotid arterial stent insertion and coil embolization, both patients died because of repeated bleeding from the pseudoaneurysms. CONCLUSION: In patients with persistent pain in irradiated sites, clinicians should be suspicious of progressing or impending CBS, even in the three-dimensional conformal intensity-modulated radiation therapy era.