Hi Pippin.  I used Aveeno Moisturising body lotion throughout my radiotherapy and had no rashes or burns.  Your radiotherapy team should also be able to advise you how to treat the rash and irritation.  Don't put any creams or lotions on immediately before your treatment.  I used to wait until after and once I was home to apply the lotion.  Hope you get something sorted. 

Carol xx  

Hi Carol, I've just bought some aveeno and also some aloe vera gel  so will see how it goes. How are you doing atthe moment? Xx