"The prostate gland and the seminal vesicles are responsible for creating the fluid that makes up semen. Consequently, most men report a decrease in their amount of ejaculation. Men are still able to experience orgasm though their ejaculation will be reduced. about
5% of patients who have undergone brachytherapy report completely dry orgasms, while about
5% of brachytherapy patients report no change in their ejaculation. Some patients report pain with their first ejaculation after the brachytherapy seed implants. The pain, however, subsides with subsequent ejaculations.
Generally, most doctors believe that the testicles will continue to produce sperm after the brachytherapy seed implants. Some patients have been able to conceive healthy children after receiving brachytherapy. Most doctors, however, advise not trying to conceive until at least 18 months after brachytherapy, though it is unlikely that potential children would be affected. Younger men who undergo brachytherapy and still want to have children, may want to consider banking sperm before undergoing treatment."prostate-cancer.com/brachytherapy/side-effects/brachytherapy-side-effects.html