Radionuclide assessment of bladder-emptyingfunction in normal male population and in patients before and after prostatectomy

Radionuclide assessment of the bladder-emptying function was evaluated in 82 normal individuals and in 16 patients before and after prostatectomy. The parameters evaluated were: average flow rate (AFR), peak flow rate (PFR), corrected peak flow rate (CPFR = PFR/[bladder volume] 0.5), ejection fraction (EF) of the bladder, and post-voiding residual urine (R U) volume. A good interobserver reproducibility was found in 19 measurements. Urinary flow rates, EF, and RU showed a highly significant statistical difference between normal individuals and patients before surgery: AFR, 9.2 ± 5.1 vs. 2.9 ± 1.5 mL/sec; PFR, 19.5 ± 9.2 vs 7.4 ± 3.2 mL/sec; CPFR, 1.17 ± 0.34 vs 0.54 ± 0.22; EF, 95.6 ± 4.6 vs 68.2 ± 23.2 percent; and RU, 11.8 ± 15.8 vs 93.4 ± 115 mL; respectively. After prostatectomy the urinary flow rates showed a highly significant improvement and did not differ from the normal individuals: AFR, 7.9 ± 2.7 mL/sec; PFR, 19.0 ± 6.4 mL/sec; and CPFR, 1.32 ± 0.57. The EF after surgery (91.7 ± 10.9 %) was lower than in normal individuals, but showed a significant improvement compared with EF before surgery. The RU after surgery (27.4 ± 48.0 mL) although lower than before surgery did not differ significantly and was greater than in the normal individuals. No relationship between age and f low was found in this study. Both average and peak flow rates were related to the bladder volume. This method involves a single, noninvasive procedure which enables determination of bladder-emptying function.