Hi "Worried Daughter",
Welcome to the forum. I am really sorry that your mother has to go through all of this at her age, especially after fighting cancer twice already in her life. Head and neck cancers are kind of nasty because of their sensitive location.

I also had radiation (and chemo) only. I lost 60 lbs because I refused to get a PEG tube. The chemo was pretty rough - it might be easier on your mother since you didn't mention that she is getting chemo. Radiation is very hard treatment -many say worse than surgery. The effects peak out starting towards the end of treatment and continue for several weeks after the end of treatment. Her taste buds are probably already wiped out but they will start to recover several weeks after the end of radiation.

Most people are able to maintain their weight, which is necessary for healing, with a PEG tube. The body needs fuel and sugar is a fast way to get it - don't worry about feeding the cancer. My doctor ordered me to eat ice cream. She is very thin to start out with so working closely with a nutritionist and possibly a PEG tube will be critical for her care. You should meet with the nutritionist weekly.

Stay on top of pain management -it is also vital.

Thrush and infections are other areas to be watchful for. Radiation does a number on the immune system and also causes xerostomia (dry mouth).