I'm sorry to hear this news. It just sucks doesn't it.
My Husband Kris had a recurrence 10 months after finishing rads and chemo.
He was told that without surgery he had less than a year to live.
This will be salvage surgery. Salvage surgery is brutal and has many long term consequences for the patient. Those who think they have it bad after rads and chemo don't know nothing.
Now , for the good news. This will "salvage " your Mothers life. That's the point of it.
Kris is 2 1/2 years post his salvage surgery now. He is doing just great and I couldn't be more proud of how he has coped and adjusted. There is still really good life to be lived after Salvage surgery. Please do not dismiss this option for your Mother. I don't know of course, exactly what her salvage surgery will consist of, but this will be the only way to persue a cure. Radiation has not worked, so why would another round make any difference. It's also not long since your Mother completed her rads.
Take a deep breath. Talk long and hard with the surgeon/team. Make sure you understand fully what to expect. Then , put one foot after another, and you will be amazed at how you all cope.
Thinking of you all,
Tammy

Caregiver/advocate to Husband Kris age 59@ diagnosis
DX Dec '10 SCC BOT T4aN2bM0 HPV+ve.Cisplatin x3 35 IMRT.
PET 6/11 clear.
R) level 2-4 neck dissection 8/1/11 to remove residual node - necrotic with NED
Feb '12 Ca back.. 3/8/12 total glossectomy/laryngectomy/bilat neck dissection/partial pharyngectomy etc. clear margins. All nodes negative for disease. PEG in.
March 2017 - 5 years disease free. Woohoo!