Thanks for all the replies and advise, I thought I would point out I had HDR brachytheraphy plus 6 weeks of EBRT, not surgery.
My problem I am told is, due to my staging and the extensive area, 70% of prostate, prostate shell and possibly one lymph node, the follow up EBRT target area was very wide. This has meant a worsening outlook for radiation prostatitis, bladder fibrosis, both of which have already appeared in a mild form.
I can't complain, I feel fine in myself, working and active but we are looking at taking time out for ourselves, including possibly moving somewhere warmer for the winters being medication free would, if possible, be brilliant.
We currently are fine with using Sildenafil when needed, but it needs an hour and results in mild nasal congestion. I would love to not need this and I know my condition has improved dramatically over the last 18 months, but it is still very hit and miss.
Will talk to my doctor and niece, she is a consultant in geriatrics which includes prostate cancer, and see what they advise and I will try other PDE5 drugs, but still interested in whether the 12 month course works, especially after PCa.