I don't know if you want to pay for a lot of second opinions, but I hope you will find a way to talk to an HDR brachy
monotherapy expert and an SBRT expert.
Albert Chang has replaced Jeff Demanes as the HDR brachy expert at UCLA. Your other choice would be Mitchell Kamrava at Cedars-Sinai. He trained under Jeff Demanes as well. I think either will be just fine.
My RO, Chris King, is THE man for SBRT. He invented it for prostate cancer in 2003. He has been mentoring Amar Kishan, who I know as well. Amar is one of the smartest and nicest doctors I've been fortunate to meet. He takes my breath away with the depth of his knowledge. Either would be fine to talk to.
I've met all of those doctors (except Dr Chang - I'll be meeting him in 2 weeks with a patient). They all practice what they preach about
shared decision making. They will give you all the info they can for you to make a decision, and will expect you to call the shots. Both SBRT and HDR brachy have very high rates of potency preservation, which is why I narrowed my own choice to those two.
Demanes reported a 10-year potency preservation rate of 60-70% for the both the boost therapy and the monotherapy. Urinary dysfunction, mainly urethral stenosis, was slightly higher with the boost therapy (7% late term grade 3 vs 5%).
www.redjournal.org/article/S0360-3016(04)02264-3/fulltextwww.redjournal.org/article/S0360-3016(15)03101-6/abstractI know that Kaiser San Francisco offers SBRT. I don't know if they do HDR brachy. I think with his diagnosis, he can wait until next year if he has to. But that is a good question to ask those doctors. I am just amazed that they would send you a letter like that. I would be demanding that doctor come up with the evidentiary basis for making such a claim.