Any doctor who knows anything about prostate cancer will know about the ultrasensitive PSA test. Are you being treated by an oncologist or just a urologist? You should have (at least) one of each on your team. I'd strongly suggest that you seek the help of a real expert in prostate cancer. I've suggested Stephen Strum MD (Oregon), Mark Scholz MD (Los Angeles), Charles "Snuffy" Myers (Virginia), Eric Small MD (San Francisco) and Derek Raghavan (MD Anderson Houston). These doctors are tops in their field and it will take you some time to get an appointment with them. With all respect to others here, I wouldn't wait to take action. At 0.5 your PSA is too high and I would assume that you have residual cancer until proven otherwise. On the other hand you definitely need to determine whether RT would be helpful before pursuing it. This is where the experts come into the picture. They will cost you some $$$ but if you can swing it they are well worth the cost. My pure guess as to what they would do is get you on ADT fairly quickly (for maximimum cancer cell kill), put you through a battery of tests to determine if there has been spread to bone or lymph, and given the results of those tests determine whether RT would be beneficial. If it would not then ADT, chemo or one of the investigational therapies would probably be pursued. By the way, in the meantime I'd suggest that you buy Stephen Strum's book, possibly Snuffy Myers book, cut way back on fatty foods, get lots of deep dark green veggies, whole grains and check into the supplements that have been shown to be effective against prostate cancer. My best to you. I think you might have a good shot at licking this if you act deliberately and aggressively.