That's great! Celebrate success.
LDR brachy plus EBRT practice defines "cure" by long term PSA remaining below 0.2. Here's a link to their explanation of that concept Using Zero PSA at 15 Years to Determine Treatment
They have a very large database of cases they've treated, and they do claim to have a decent success rate achieving that goal. So, yes, it is possible.
(I went through their screening in 2013 with my parameters. Out of their 14,000 member database [at that time], they found only 52 cases matching mine. The success rate with those cases was barely 50%. Their marketing efforts are fairly aggressive, yet they suggested if I had a plan in mind already locally, that probably I should do that. It didn't sound like I would help their success rate!)
55@Dx on 4/16/13. PSA 5.2, G9(5+4), cT3a by MRI.
IGRT - 44 sessions (79.2 Gy, 50.4 Gy pelvic)
ADT2 - Lupron+Casodex (3 yrs)
PSA <0.1 : 8/13 - 5/16; steady at 0.7+/- 0.1 since 3/17My Story