I think with positive margins your result is not unexpected and it looks like your PSA rise is slow which is a good sign.
I had negative margins and PSA rose around a year after surgery. My doubling time was 1.2 months on one measure.
My understanding post negative margins is that if PSA is 0.2 or above (some now say less) and it has recurred in less than 3 years and the PSA doubling time is less than 6 months it is highly likely there are mets. If the rise occurs greater than 3 years after surgery and the doubling time is slow then it is more likely to be a local recurrence. I remember my surgeon talking me through this at post operation review.
Post positive margins and given the PSA rise you are seeing is relatively slow this is a relatively good sign I think.
Not easy to deal with as we always hope surgery or radiotherapy cures us but in recurrence (or progression) terms the slow rise post positive margins is the better scenario.
I really hope that RT when it comes cures you completely.
Best wishes, Ian.