There is nothing wrong with your reasoning; I came to the same conclusion after months of research.
There may be some benefit to surgery for a younger patient, but this is still speculation and not supported by any evidence.
If radiation is done correctly it will kill all of the cancer in the prostate and hard to get margins, such as near the ureatha and seminal vessels and achieve a better margin in the prostate bed.
If you have a local reoccurrance after surgery it is because some PC cells were either left in the margins or in the bed and these can be cured by salvage RT. Another benefit to surgery is that you know your actual gleason score and if you have positive margins.
The side affects from radiation are usually less severe than surgery and the side affects show up later, as with surgery they are immediate.
Both surgery and radiation have the same cure rate for localized PC.
I would also investigate a combination of seeds and IMRT as you get a much higher dose with the same side affects as IMRT alone.
Keep researching and good luck on whatever decision you make.
64 years old.
PSA rising for 10 years to 40, free psa 10-15. Had 5 urologists, 12 biopsies and MRIS all neg. Doctors DX BPH and continue to get biopsies yearly. Positive Biopsy in 10-08, 2 cores of 25, G6 less than 5%. Scheduled Surgery as recommended.
2nd Opinion from Dr Sholtz, an Oncologist said DX wrong, path shows indolant cancer, but psa history indicates large cancer or metastasis. Futher tests and Color Doppler confirmed large transition zone tumor that 13 biopsies and MRIS missed. G 4+3 approx 2.5cm diameter.
Combidex MRI in Holland eliminated lymphnode mets. Casodex and Proscar reduced psa to 0.6 and prostate from 60mm to 32mm. Changed diet, no meat and dairy.
Seed implants on 5-19-09, 3 hours door to door, no pain, minor side affects are frequency and burining urination. Daily activities resumed day after implants.
Scheduled for 5 weeks IMRT in July