The purpose of this study is to see if botox injection into the prostate during seed implantation (brachytherapy) for prostate cancer a) improves urinary symptoms or avoids need for urinary tract instrumentation over the 6-8 month post-operative period when one wants to avoid manipulating the radioactive seeds, and b) speeds up the drop in PSA. Patients will be randomized to botox vs saline injection, at the completion of the seed implantation procedure.