The main protection measures for radiotherapy localization lines are to protect them from being erased and to keep a marker pen to mark unclear localization lines at all times. There will be localization on the body surface before radiotherapy, marking on the body surface, this marking line is conducive to accurate radiotherapy in the future. After the marking line is done, the patient should try to avoid rubbing the marking line, such as repeated rubbing and getting wet. Especially when bathing, the localization can be covered with a protective film. In addition, you can also have a marker on your body, and use the marker to supplement the unclear marking line in time, so as to keep the marking line clear and not to affect the accuracy of the localization line. Therefore, radiotherapy localization line should pay attention to local friction, appear unclear, mark again in time, most will not affect the treatment.