In this prospective study patients had to have prostate volume ( PV ) < 50 mL , International Prostate Symptom Score ( IPSS ) of 7-18 , Quality of Life score ( QoLs ) > 3 , a maximal flow rate ( Qmax ) of 5-15 mL/s , with post voiding residual volume ( PVR ) < 150 mL and serum prostatic antigen ( PSA ) < 4 ng/mL .