Prospective four years of evaluation of erectile function after low-dose-rate prostate brachytherapy using baseline IIEF-5 > 16

Purpose
Prostate brachytherapy (BT) is a validated treatment for localized prostate cancer (CaP) and an attractive therapy option for patients seeking to preserve erectile function (EF). The aim of this paper is to prospectively assess EF evolution during 4 years after BT.

Material and methods
Between February 2007 and July 2012, 179 patients underwent an exclusive Iodine-125 BT, for low-intermediate favorable risk CaP of whom, 102 had an initial international index of erectile function 5 score (IIEF-5) > 16 and were included in the study. Of those, 12.7% received neo-adjuvant hormonotherapy (HT) to decrease the prostate volume. Post-BT intake of phosphodiesterase inhibitors (PDE5i) was not an exclusion criterion. Erectile function was prospectively assessed using a validated questionnaire IIEF-5 before treatment and annually for 4 years.

Results
At 1-year follow-up, 54% of patients preserved an IIEF-5 > 16 and only 8% suffered from severe ED. During the next 3 years, the results were not statistically different. The mean IIEF-5 lost 4 points during the first year, 17 vs. 21, and remained stable during the following 3 years. We did not find any significant differences in the proportion of patients treated by PDE5i (18-20%). As for patients with a normal preoperative IIEF-5 (> 21) (n = 52), 35-42% preserved a normal EF and 71-77% maintained an IIEF-5 > 16, including 13-19% of patients who needed PDE5i. Those results were stable for over 4 years.

Conclusions
During the first 4 years after BT, more than half of patients maintained an IIEF-5 > 16, and EF results remained stable. Severe erectile dysfunction (ED) was very rare.