So sorry to read this.
I'm hoping you have had your Brother get a second opinion.
Is there not an option of salvage surgery? I know that this can be extreme but it is worth it.

If this really is terminal, I would suggest you contact your local hospice for assistance . They will help to ensure pain relief is adequate and guide you all through the process while providing practical help with caring for him.

Thinking of you and your whole family,
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!