You must be comfortable with your decision. I am pro-Brachytherapy because it was the best choice for us. My husband has been fortunate, none of his seeds migrated and he has had very few, if any side effects from his treatment. If you have any questions, ask away I'd be happy to fill you in on our Brachytherapy journey.
FYI, the information we received from the Brachytherapy specialist is that studies are showing a success rate near that of surgery with today's brachtherapy techniques.