Surgery to treat prostate cancer usually requires cutting the tubes between the testicles and urethra that transport the sperm and semen. Furthermore, surgery removes the prostate and seminal vesicles that produce the semen. Radiation significantly decreases the amount of semen that is produced, and semen is necessary to carry the sperm. This makes it impossible to father children without highly sophisticated sperm retrieval and in-vitro fertilization procedures.
If you want to have children in the future, it may be a good idea to bank sperm before cancer treatment. Speak to your doctor if you want more information or have questions.