Hi all, thanks for your feedback/comments, I had these occurrences twice over last weekend & both occasions were at night. I spoke with the radiotherapist on Monday who suggested it could be that as my bladder is full while I am asleep & my muscles around my bladder are working overtime & then not releasing when I do finally try to go. So the suggestion was take ibuprofen just before bed which should help relax the muscles, not drink 2-3 hours before bed & if I wake up needing a wee then get up and go and don't try holding off.
So the first couple of nights I tried the above, then cut out the ibuprofen for the next couple of nights and so far all is good no further incidents.
Once again thanks for your comments