I used coconut oil and never experienced any burning or discomfort during my treatment. I was giving this advise from a friend that worked at a cancer care treatment center. Best of luck.

Make sure you ask your oncologist, you do not want to mess up what they are doing

Do get approval firm your RO; they may approve items they hadn't specifically recommended, but, I. The event they say NO to a product, they probably have good reason. If you feel strongly about a product bring supportive evidence to them.
I used calendula, straight aloe and EV coconut oil.

((Hug))

I used aloe vera gel on my radiation burns and surgery scars. Did not do much for my scars but my radiation burns are now non existant and it only took about two years to completely clear up.

I used Aquaphor when the burning got bad under the breast. Worked well and only took a couple of weeks after I stopped for things to clear. I did go braless at home the last couple of weeks, which is what the RO recommended. Hope things workout for you.