Hi Marilyn,
My husband is currently in the middle of his 4th week (tomorrow will be 18 & 19 of 42 radiation treatments) to his entire neck. He has the PEG tube and has yet to use it for food. Granted he is living on scrambled eggs and chicken soup but he is doing it. We really were not given the choice, the doctor says you will get a feeding tube so he did (we didn't mind though, we are those people that will pretty much do what the Dr tells us too)
Everyone is different so it is hard to say whether you would be able to do it or not. I have seen some say they were using one by 2 weeks in and like I said here we are my husband almost done with his 4th week and he hasnt used it (except for medecine because otherwise it burns his mouth)
Your doctor can give you their advice and you should really do what feels right to you, it is YOUR body.
Take care and Good Luck,
Brandi