Erectile dysfunction and radiation therapy for prostate cancer

The number of patients diagnosed with early stage prostate cancer (PC) has increased dramatically, because of routine prostate-specific antigen testing in the recent years and the possibility for cure of early disease. Radiation therapy is together with radical prostatectomy the most effective treatment for localized disease. Incidence of erectile dysfunction (ED) after radiotherapy (RT) reported in the literature vary from 6% to 84% after external-beam RT to 0-51% after brachytherapy. Most of these studies are retrospective, the definition of ED is variable and sexual functioning is frequently assessed by asking only one question. Already in the 1980s it was suggested that post-radiation ED was attributable to vascular damage. More recently, a strong relationship between radiation dose and volume of the penile bulb has been found. Though, a multifactorial etiology has to be considered taking into account pre-treatment erectile function. If radiation induces vascular damage that causes ED, any means of reducing the dose to the pelvic vascular structures would likely decrease ED. Patients need to be informed about the availability of effective treatments such as PDE5-I, intracavernosal injection and vacuum devices.