The side effects of radiotherapy for esophageal cancer are as follows: 1. Acute radiation dermatitis: appearing 10-20 days after radiotherapy, the time of appearance varies from person to person; 2. Radioactive esophagitis: appearing after 2 weeks, manifesting as pain in the throat and difficulty in swallowing; 3. Radioactive tracheal reaction: patients show symptoms such as dry cough and no sputum; 4. Radioactive costochondritis: rib damage or even fracture after radiotherapy; 5. Esophageal perforation: the condition is serious and even fatal; 6. Esophageal stricture: in the distant stage of radiotherapy, local fibrosis and scarring in the esophagus cause esophageal stricture; 7. Dietary difficulties: leading to nutritional disorders and digestive tract reactions.