After radiotherapy , tissues start to slough out even after many years usually 18 months to 3 -4 years because that is how the radiotherapy basically acts . It causes damage so that the malignant cells when they try to multiply, they will not be able to do so. The bleeding may be due to radiotherapy taking into consideration that his PSA is within normal limits.
However in this age group and especially a smoker, hematuria
( bleeding in urine ) cannot be taken lightly and a certain tests are must to rule out serious causes.
I would suggest to undergo following tests:
1. urine cytology
for malignant cells
scan abdomen and pelvis
has to be done: your father need not be apprehensive about undergoing it as it will be a painless endoscopic procedure which will give information about the cause
4. PT and PTT : this will give idea about his coagulation profile as he is on Ecospirin.
Send the details of previous surgery which was done for prostate cancer
and the recent reports so that i will be able to answer you better.