The side effects of radiotherapy are related to the radiotherapy site, for example: 1) radiotherapy for intracranial tumor: causing headache, nausea, vomiting, increased intracranial pressure, etc.; 2) radiotherapy for nasopharyngeal cancer: causing dry mouth, mouth ulcer, difficulty in swallowing, etc.; 3) radiotherapy for esophageal cancer: causing local edema, increased difficulty in swallowing, etc.; 4) radiotherapy for lung cancer: causing cough, coughing sputum, coughing blood, difficulty in breathing, etc.; 5) radiotherapy for rectal cancer: causing blood in stool, rectal stenosis, etc.; 6) radiotherapy for bladder cancer: causing bladder hematuria, bladder atrophy, etc.; 7) radiotherapy for breast cancer: causing skin damage, etc.