Silvadene (silver sulfadiazine) Check with your radiation doctor first. I usually give prescription for silvadene (silver sulfadiazine) since its inexpensive. However there are other preparations. Clean the skin gently with dove or dial soap and water using only your hand. Do not scrub with anything even a wash cloth. Then apply the silvadene (silver sulfadiazine) twice a day and no other tape or gauze. When washing each day you do not have get all the silvadene (silver sulfadiazine) off.
See your MD. Not a question for the internet. See your doctor. Likely requires professional management after seeing the extent and severity.
Hydrating ointments. Hydrating ointments natural like aloe or aquaphor is to name a couple.