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Abstract

Head and Neck Cancer (HNC) is the sixth most common cancer worldwide. In developing countries like India, 60% to 80% of cases are diagnosed only in advanced stage. The vital structures of head and neck region are infiltrated by the malignant cells, interfering with normal functions, like swallowing, breathing etc. Therefore, these patients are treated aggressively, with combined chemotherapy and radiotherapy (RT). Neck radiation has emerged as the most extensively used treatment modality, when vital organ preservation is considered. Ionizing waves used in RT, generates Reactive Oxygen Species (ROS) and free radicals. ROS are not only responsible for arresting the proliferation and killing of cancer cells, but also cause radiation -induced long-term complications. The incidence rate of late complications like Baroreflex failure and cardiovascular autonomic dysfunctions have tremendously increased over the past few years, due to advancement in treatment modality, increased survival rate, clinical awareness of radiation injury. Several mechanisms have been postulated for radiation induced baroreflex failure. The ROS leads to chronic inflammation of the irradiated neck region results in carotid artery fibrosis, causing baroreceptors malfunction. In addition to this, the afferent nerves coursing from the baroreceptors are damaged leading to baroreflex failure and altered cardiovascular autonomic function. Reduction in tonic inhibitory input to the vasomotor center, causes increased sympathetic outflow, resulting in impaired control of blood pressure and heart rate.