Early intervention with phosphodiesterase‐5 inhibitors after prostate brachytherapy improves subsequent erectile function

Abstract

To examine the early use of phosphodiesterase-5 inhibitor (PDE-5i; sildenafil citrate) in preventing subsequent erectile dysfunction (ED) after (monotherapy) prostate brachytherapy (PB, an accepted option for Gleason 6 or low-volume Gleason 7 prostate cancer), as PB is currently being offered more frequently in younger patients, and ED can be a side-effect often within the first 12 months after treatment. We examined a single-surgeon series of 69 patients who had been treated with PB from 2002 to 2005. All patients had a follow-up of ≥ 1 year; prospectively, and patients had baseline, 6- and 12-month assessments using the Sexual Health Inventory for Men (SHIM) and International Index of Erectile Function (IIEF)-6 scores. The 69 patients were divided into early treatment with PDE-5i (31) and not treated with PDE-5i (38), and their SHIM and IIEF-6 scores were compared at baseline, 6 and 12 months. Daily sildenafil (25-50 mg) was given immediately after PB for 12 months. Overall, for the entire group, the mean prostate-specific antigen (PSA) level was 6.8 ng/mL; 78% had Gleason 6 cancer and 20% had Gleason 7 (3 + 4) cancer. The mean age in the early PDE-5i group was 64.8 years, and was 66.0 years in the no-PDE-5i group. The mean radiation dose in the early PDE-5i group was 50.2 Gy, and 43.9 Gy in the other group (P= 0.08). In the no-PDE-5i group, the mean baseline SHIM score of 17.1 decreased rapidly to 9.1 at 6 months (P= 0.01) and stayed at 9.3 at 12 months (P= 0.01). In the early PDE-5i group, the mean baseline SHIM score of 21.8 decreased slightly to 17.6 at 6 months (P= 0.2), and was maintained at 17.9 at 12 months (P= 0.2). Using the Wilcoxon rank-sum test, the 6- and 12-month SHIM scores in the two groups (P < 0.001). The IIEF-6 questionnaire confirmed the SHIM analysis. After PB patients had a significant decline in SHIM/IIEF-6 scores at 6 and 12 months. Our results indicate a 50% decrease in the quality of their erections. This provides an opportunity to initiate early intervention with PDE-5i or perhaps vacuum constriction devices or intraurethral alprostadil. In this study, the early use of PDE-5i after PB maintained erectile function at both 6 and 12 months.