Priapism as a possible acute side effect of radical radiotherapy for prostate cancer.

We report a case of a 73 year-old male diagnosed with T1 N0 M0 prostate cancer, Gleason score 7, undergoing a course of radical radiotherapy using 7600 cGY delivered in 38 fractions. Several hours after receiving his 27th fraction, he reported experiencing a painful penile erection lasting more than 6 hours. A history and several investigations were conducted to determine the etiology of this adverse event. Although several possible etiologies were considered, the two most likely possibilities were direct prostate-irradiation and/or his use of alfuzosin, a novel alpha 1-adrenergic antagonist. A literature search revealed one case of priapism secondary to radiotherapy as well as reports of priapism associated with drugs similar to alfuzosin.