Thank you Jeffmarc for your comments. Dr Amar Kishan when he treated me with SBRT in April, he suggested ADT for 1 year. I asked him what if I don't take ADT. He said my cancer coming back is 50%. ADT cuts it down by 50%. That means there is 25% chance that cancer coming back!
When I told him that Dr Schulz said that I can stop ADT now, he said it is ok!
It is all probabilistic, nothing definitive for sure!