Commenting on this paper, Thomas Pisansky, MD, the Mayo Clinic, Rochester, Minnesota, reminded listeners that about 50% of patients treated with external-beam radiation therapy and about 33% of those treated with brachytherapy already have erectile dysfunction prior to treatment. After radiation therapy [with either technology], about one-third will develop erectile dysfunction, so this problem is widespread.

“Erectile dysfunction before radiotherapy is an early warning of increased risk of cardiovascular and stroke-related death. Our obligation is to make sure these patients are assessed appropriately. Also, erectile dysfunction is associated with depression, anxiety, and loss of self-esteem, quality of life, and intimacy, so avoiding it has important implications for general well-being” Dr. Pisansky said.

Radiation-related erectile dysfunction is incompletely understood, but may be partly explained by adverse effects on the vasculature. Androgen-deprivation therapy can also reduce the likelihood of erectile dysfunction, he continued. “The surgical literature shows that use of a phosphodiesterase type 5 inhibitor [like sildenafil] improves erectile function. This is a well designed study with minor limitations that do not detract from the conclusion that once-daily sildenafil improves erectile function in patients undergoing radiation. It would be good to know the experience of partners of these subjects, but this was not assessed in the study,” he said. ■

Disclosure:Dr. Pisansky reported no potential conflicts of interest.