a PSA of 4, following RT & HT I would think a bit high - but then, I'm no expert.
I cannot understand why men are not offered a PSA test over a certain age &/or if there is a family history of PC.
Provided the man, keeps away from being "Naughty" for 7 days before the test, I think it's pretty accurate.
For any chaps reading this, provided there is a choice between removal or HT/RT - I would go for the latter, every time - less invasive & you are still a bit more "Intact".
All the very best.