Recent studies confirm that those treated at a CCC have better outcomes and survival rates.
This may well be due to the fact that they have more expertise and experience in treating head and neck cancers. CCC's treat thousands of these cancers every year. Your local hospital may only treat a dozen or so.
Personally I would head straight for a CCC. This cancer is aggressive and it warrants treating correctly/according to the NCI guidelines the first time. Recurrences are always more difficult to treat and you do not want to go there.
Personally I have not heard of anyone else being treated with Brachytherapy for this and it raises a red flag for me.
Seek out a second opinion at a CCC, maybe from 2 CCC's. I wish your brother all the best.
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!