Welcome to OCF!
There are several members who have had radiation twice, a couple here have done it 3 times. The decision to re-radiate is done on a case by case basis.
Chemo alone would only be used for palliative care. Time is of the essence in recurrence cases. I suggest to make certain he is being treated at one of the country's top comprehensive cancer centers (CCC). It really does make a difference! Even if your father is happy with his current doctors, at least go to a CCC for a second opinion. At a CCC a whole team of specialists will discuss each individual case at a meeting to all decide what the best treatment plan would be. Please talk to your family and get them to see the importance of immediately getting your father to a CCC so he can get thru this.
Many survivors live good lives with a feeding tube and/or trach. It is NOT the end of the world to live with these things, of course its different and at times challenging but its still a life worth living. To someone who has been healthy it appears to be a horrible life but I think its so much better to have a life even if the patient has a couple of issues. I almost quit before I was treated for my third round of OC but because of the wonderful people here I persevered and underwent a huge operation. They convinced me not to quit before I even tried to get well. Here it is almost 4 years later and even with my limitations, I have a great life. I hope your father and family can see the end result and at least try to have your father treated.
Best wishes!!!
CCC list