Erectile dysfunction after radiotherapy for prostate cancer.

Erectile Dysfunction (ED) is a relatively common complication after radiotherapy for prostate cancer. The etiology of ED is unclear. It is likely related to age, pretreatment erectile function, androgen deprivation therapy, and the volume of tissue irradiated. It is unclear whether the dose to various parts of the penis, such as the penile bulb and corpora cavernosa, is related to the development of ED. Following radiotherapy, the early use of phosphodiesterase inhibitors probably reduces the risk of ED.