Congratulations on your great PSA test result. Except for our difference in age, our journeys are very alike (see my signature).
My first PSA result, about 6 weeks after EBRT, was 0.05, down 50% from when I started radiation. My first 6 month test will be in July and I'm hopeful that it turns out as good as yours.
Hopefully we will both be blessed with very, very low PSA test results in the years to come.
All the best to you.