Best of luck with your radiation treatment, it sounds as though you have given your skin a great headstart and hopefully you will have few problems. My skin did breakdown in the last week or so of treatment (25 sessions) but the nurses were available each day to soothe and dress the area with a combination of Moo Goo cream (lovely stuff) and pawpaw ointment under the dressings. A cool washer applied to the area was also very soothing.
The staff at the radiation oncology unit I went to were wonderful and went to great lengths to explain everything and answer my questions, particularly in the beginning when it was all so new. Hopefully you will experience the same level of support and care.
Best wishes, Jane