To some extent, additional ADT and additional radiation dose are probably interchangeable, but there are still a lot of unknowns.
In the following retrospective study, each month of additional ADT decreased the risk of salvage radiation failure by 10%. Going up to 2 years decreased the risk of failure by 9.8 fold.www.redjournal.org/article/S0360-3016(13)01075-4/fulltext
If you haven't seen it, the following article makes the case for higher dose:/pcnrv.blogspot.com/2016/11/dose-escalation-for-salvage-radiation.html
As you said, it's water under the bridge for you at this point, but I'm glad you are asking all the right questions. That's the most any of us can do.
Allen - not an MD
•PSA=7.3, prostate volume=55cc, 8/17 cores G6 5-35% involvement
•SBRT 9 yr onc. results
•SBRT 7 yr QOL results
•treated 10/2010 at age 57 at UCLA,PSA now: 0.1,no lasting urinary, rectal or sexual SEsmy PC blog