Thank you Ann-Marie and David!
We have just made an appointment with an excellent oncologist and we're having a meeting with him on Feb 23rd.
We've also been talking to mom about it and she has agreed to listen to her GP and this oncologist to see what advice they give (her GP is excellent and he is already looking for a second opinion among oncologists he knows and trusts). Yet, she says she has practically made up her mind about it and she won't have rads. It has to be her decision independently from whether she's advised to or not. Her being 84 and too weak, with all the surgeries she's been through plus some other things she's been through in these past few years has taken its toll on her. It's a very delicate thing, of course we want her to be OK and she wants to be OK too but her perspective is different from that of someone younger. Her GP's fear is that she won't be able to take it.
Thanks for your answers, I'll let you know what she's decided.