Several months ago I was exactly where you and your father are now. At the time (October?), there was a long string of posts on this forum entitled "sitting on the fence" that addressed exactly what you are asking now.....how do you decide on surgery vs. BT? You may have to go through a number of pages to find it but I strongly recommend that you do.
I was initally leaning toward a radical surgery. After talking to my urologist, a second urologist, my radiologist and reading the actual experiences of the guys on this site (and particulary that string), I changed my mind and opted for BT (performed last Friday) to be followed by 25 treatments of IGRT in two months. While there are risks with any option you choose, I came to believe from reading the accounts on this site (and talking to others in person) that there were fewer "quality of life" issues with BT/Radiation than with either radical or robotic surgery. I can't prove that and may be wrong....but that's what I felt. That factored heavily into my decision and I am very comfortable with my choice.
That said, I totally understand the mindset of those who "just want it out"...had some of those same feelings myself in the begining. I have learned that a case of PC is almost like a snowflake....they are all different based on the individual's stats, age, physical condition, frame of mind, etc.etc.etc. There is probably no "exactly right" answer. You are doing the right thing by learning as much as you can, educating your dad and then going with the option open to him that he is most comfortable with.
Best wishes on your journey....you will find a lot of support and information on this site.
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Age - 67 PSA - 4.5 Gleason 3+3 = 6 Ct and Bone scans - negative
BT performed on 12/11/09 - 84 seeds of Palladium 103 To be followed by 25 treatments of IGRT in February.
No unexpected issues from the BT so far. All after-effects just as docs alerted me to expect (and members of this forum have reported).