The causes of impotence are arteriogenic, neurogenic and pyschogenic in nature. After radiotherapy the most likely cause of erectile dysfunction is arteriogenic.65,69,70 Goldstein et al. postulated that postradiation impotence is secondary to damage to the internal pudendal and penile arteries.70 Radiation causes proliferation of the intima of vessels and is prothrombotic, favoring atherosclerotic plaque formation.71 The histologic changes after radiation therapy were initially demonstrated in animal studies, where damaged vessels became sites of fibroblastic proliferation and lipid depos-ition.72-74 These changes would certainly impede blood flow to the penis and cause erectile dysfunction. It is not surprising that a higher percentage of patients after radiotherapy present with erectile dysfunction, if they have a history of hypertension, atherosclerosis and tobacco use.70
In contrast to the factors affecting erectile dysfunction after radical prostatectomy, younger age did not seem to play a significant role after radiotherapy in some studies.58,60,64 Instead, preradiotherapy sexual dysfunction, vascular disease and diabetes were significantly associated with the development of impotence.61,66 Thus, normal potency status prior to radiation treatment increased the chances of retaining potency.59 Zelefsky etal. also found no correlation between prior transurethral resection of the prostate or neoadjuvant androgen deprivation in predicting erectile dysfunction after radiotherapy.64 Likewise, Formenti etal. reported that moderate dose adjuvant radiotherapy, 45-54 Gy, did not affect sexual potency after radical prostatectomy.75,76
Was this article helpful?