Karen
not really got a positive answer for you.
My graft was taken from the inside of my forearm, seems to be first choice here in the UK. I was told when I had some problems with tissue dying that a pectoral graft would have been the surgeons next choice.
So maybe a forearm graft is something you can ask about, surgery after radiation I cannot help with. BUT is there any chance that the fistula will heal with time(I suppose that is wishful thinking on my part.)
Wish I could help more..
Sunshine.. love and hugs
Helen