It would have been more helpful if the doctor had discussed, even briefly, the pros and cons of various treatment options. It
is difficult, and risky in terms of terrible side effects, to do surgery after radiation, but if your PSA rose after radiation there's no guarantee the cancer would still be curable by radiation anyway. Not to say that you shouldn't take the "radiation makes surgery risky and difficult" argument into account when making your decision, but consider the "pro" side to radiation as well. And it's considerable.
The "pro" to
radiation? It ain't surgery. Don't underestimate how major of an operation a prostatectomy is, even if done robotically. I've had both, and believe me, radiation treatments are about the easiest medical procedure to undergo. Cons? Well, the one we just discussed, plus the fact it's not free from side effects--bowel irritation, ED, bladder irritation--or even more serious injury.
There are pros and cons to every treatment option.
Surgery seems to offer an edge in cancer control in the long run, but as I understand it this generally means men who are relatively young patients (in their 50's). In the shorter run, surgery and radiation (external or seeds) have comparable outcomes, according to Walsh. As noted, you can have followup radiation if needed after surgery to mop up stray cancer cells if needed. You get the (not-to-be-underestimated) psychological benefit of "getting it out".
Like the others, I urge you to take the time to read. I really like Walsh's book. He's a surgeon, but he doesn't advocate it for every patient.
If protons are feasible given your situation and location, I would carefully consider that option, as well as plain old external beam radiation, brachytherapy (seeds), combining brachy and seeds, etc. Protons are famous amongst many men who have had that treatment for being low or non-existent in side effects, but it's still not
free of the risk of side effects.
You can start by scanning some books, articles, and websites, and then followup by consulting doctors who practice the various treatment modalities.
Don't rush--this is an important decision. Your big chance to knock one out of the ballpark.
Best wishes.