Hi Bazzer,
Sorry about your situation. You could say it was fortunate they found a sample on one pin as they could have missed it. Although after an MRI they are supposed to be able to target the biopsy needles better so perhaps it is a very small lesion.
If they had missed it they would likely have done a template biopsy which doubles the number of needles under general anaesthetic or perhaps had another go at what you had.
They often leave the choice of surgery or RT to the patient.
They can monitor your psa and decide when it's best to have the RT. We don't know what your psa is. It sounds like yours might be low, say under 10 in which case they might try to get your psa down to under 2 which shouldn't take too long. It's better not to stay on hormones too long as your lesion adapts to them and they stop working, that could take anything from months to years but even so it restricts your future use. They often put you on hormones after RT for a few months. I was offered 3 months hormones, RT followed by 3 months hormones although I chose surgery.
I'm not an expert on these matters so others might expand or adjust what I've written. Good luck with your bone scan. All the best, Peter