What is the probability of skin necrosis if I want to do facelift surgery after head and neck radiotherapy?

Hello,There are too many variables to address your question with a big degree of reliability.  Things to consider are - location of the radiation, how long after your radiation treatment are you, how much radiation was provided, your age, underlying medical conditions...I can expound more but as you can see, there is no easy answer without more information from you.  

The risk of necrosis after radiation is high. I would not recommend a facelift for you. You will only be flirting with disaster