Radiation-induced brain injury (RBI) is one of the severe complications arising from the radiotherapy of head and neck malignant tumors, characterized by significant cognitive decline and impaired learning and memory. It adversely affects patients’quality of life and can even be life-threatening in severe cases. The pathogenesis of RBI remains unclear, but it may be related to factors such as cerebrovascular injury, glial cell injury, inflammatory responses and free radical injury. Traditional Chinese medicine (TCM) attributes RBI as a consequence of the body’s inherent weakness and the invasion nature of radiation, which is clinically manifested as a condition of original deficiency and solid injury. In addition to symptomatic treatment in Western medicine, TCM therapy has been progressively incorporated into clinical practice. Recent studies have focused on synaptic plasticity to elucidate the underlying mechanisms, offering novel perspectives and a theoretical foundation for advancing the role of TCM in the treatment of RBI. This article reviews the latest literature on the pathogenesis and treatment of RBI from the perspectives of both traditional Chinese and Western medicine.