Fig. 1.

Schematic drawing of male genitourinary system and the nerves that are in or in proximity of radiation treatment fields for prostate cancer. A) is the sacral nerve root that gives rise to the (B) pudendal nerve and eventually (C) the dorsal penile nerve that is important for sensation during intercourse. (D) is the prostatic plexus that lies within the prostatic fascia and is most susceptible to radiation damage. The prostatic plexus gives rise to the cavernosal nerves that help control the neural input for erections.