Advances in mucosal injury mechanisms in radiation‐induced esophagitis associated with thoracic radiotherapy

Abstract Radiotherapy has emerged as a cornerstone modality in the management of malignant tumors. Its evolution from a localized intervention to a radical curative strategy has been particularly pronounced in lung cancer, where its role has shifted from symptom palliation to survival prolongation. Radiation esophagitis (RE) is one of the most common acute adverse effects of thoracic radiotherapy, particularly in patients with lung cancer. In the early phase of RE, the predominant features include reactive oxygen species‐mediated DNA damage and disruption of the epithelial barrier. The inflammatory phase is characterized by nuclear factor kappa B activation, edema, and pain. During the dysregulated repair phase, impaired regeneration of the esophageal mucosal epithelium, compounded by microbiota imbalance, further exacerbates tissue injury. In the late phase, transforming growth factor beta‐driven fibrosis may culminate in stricture or fistula formation. Clinically, the condition primarily manifests as dysphagia and odynophagia. The prevention and management of RE remain significant clinical challenges. This review examines key issues related to RE within the context of precision radiotherapy, with particular emphasis on its incidence and current management strategies.