The linear gas pedal introduced in the Department of Radiotherapy has an efficiency of 80% to 90% in the treatment of keloid scars, which occur in individuals with keloid scars and are formed by excessive local proliferation of connective tissue after various degrees of skin injury. The anterior chest, shoulders and back are the most common sites of occurrence. It may start as a small papule and gradually grow into a round, oval or irregular nodule with a tough, uneven but smooth surface, usually without hair growth. Over time, the color may change to dark brown and the texture may become harder. Occasionally ulcerated and infected, there may be varying degrees of itching and tingling, which is evident when the weather turns cloudy and changes.
Radiation therapy Generally, radiation therapy should be done after surgical excision. Radiation therapy should be started within 24 hours after surgical excision, and radiation of appropriate energy should be selected, with 4 to 5 Gy for 1 exposure, 3 to 5 times. The total amount is 20 Gy. The irradiation range should include the pinhole of the surgical suture, and a peripheral expansion of 3 to 5 mm is sufficient. If there is a large implant, radiation therapy can irradiate only the peripheral suture area of the implant. There are no significant acute or chronic adverse effects, and most of the hyperpigmentation that occurs can subside in a few months.