Patients aged < 68years with normal preoperative EF who underwent nsRP for localised prostate cancer ( Gleason 7 , prostate-specific antigen [ PSA ] < 10ng/mL ) were randomised after nsRP 1:1:1 to 9-month double-blind treatment with tadalafil 5mg OaD , tadalafil 20mg PRN , or placebo , followed by 6-week drug-free washout , and 3-month open-label OaD treatment ( all patients ) .