I agree with Luther that, in many ways, you are fortunate if you have a range of options and this is mostly the case with locally confined Pca.
For me, making a decision was highly complex. This is a rough guide as to why I chose the route I have chosen:
1) Surgery - a big problem for me was the risk of long term urinary incontinence. I was reading about too many people who had this problem for comfort. I also threw into the mix my age - 67 - and felt as you got older it would be more difficult to regain control. In it's favour was no hormone treatment and a "one off" procedure. I reckon if I'd been 10 years younger I might have gone for it.
2) High Dose Brachytherapy with ERBT top up. The problems with urinary incontinence, although not unknown, were pretty small. A key factor was the fact that my older brother had gone down this route pretty successfully. Downsides were the need for hormone treatment and several visits to hospital. Another was the issue of bowel problems which were more pronounced than for surgery.
3) ERBT. 37 trips over 7 to 8 weeks and a 70 mile round trip at that. Bowel problems an issue as well. I dismissed this option without too much thought.
Having made the choice, 2 further complications arose:
1) I started reading, on these threads, about fecal incontinence after radiotherapy. In fact I was coming across this too often for peace of mind.
2) I then read about the new form of ERBT - 20 sessions but at a higher dose targetted at the tumour using gold markers. I may now be offered this and I am seeing my onco next week (she in fact was a key figure in the clinical trial of this procedure).
So what I hope this illustrates is the complexity behind your choice and the huge amount of information there is to take in. In terms of being given a steer I do now recall that the MacMillan nurse who I spoke to after the diagnosis did say that you have to decide what you can live with and my fear of long term urinary incontinence swung the day - just.