Radiotherapy needs to protect normal tissues as much as possible, avoid exposure to sunlight, wear loose clothing, and keep the marking line clear. 1. Protect normal tissues: Radiotherapy is generally designed to kill tumor cells, so it must be precisely positioned before the start of radiotherapy to protect normal tissues from being destroyed as much as possible. 2. Avoid exposure to sunlight and wear loose clothing: radiotherapy itself may cause radioactive skin damage, and exposure to sunlight may aggravate the damage. At the same time, wearing loose clothing can reduce the direct friction between the skin and clothes, which can also reduce skin damage. 3. Keep the marking line clear: radiotherapy requires precise positioning, if the marking line is not clear, it will affect the treatment. Radiotherapy should also be a light diet, to prevent colds, etc. There are many precautions, remember to follow the doctor’s instructions.