Comparison of prostate volume measured by transrectal ultrasonography and MRI with the actual prostate volume measured after radical prostatectomy.
OBJECTIVE
To compare the prostate volume, as measured by transrectal ultrasonography (TRUS) and by MRI, with that of the actual prostate volume measured after a radical prostatectomy (RRP).


METHODS
This prospective study included 21 patients who had undergone RRP. TRUS prostate volumes were calculated using the prolate ellipsoid volume formula, with the anteroposterior diameter measured from axial (TRUS-V1) and mid-sagittal images (TRUS-V2). Two prolate ellipsoid volumes (MRI-EV1 and MRI-EV2) were calculated from the MRI using the same method, and planimetric volume (MRI-PV). The actual prostate volume (Actual-V) was measured in a measuring jug within 1 h after RRP.


RESULTS
Mean of Actual-V was 40.3ml (21.0-82.0). In paired sample tests, the correlation coefficients (R) for all methods were over 0.8. In a Student's t test (paired), MRI-PV (p = 0.620), MRI-EV2 (p = 0.703) and TRUS-V1 (p = 0.099) showed no significant differences compared to the Actual-V. The linear regression models of these three methods were y = 1.025x - 0.268, y = 0.946x + 2.979 and y = 1.046x + 0.381, respectively.


CONCLUSIONS
Between two TRUS volumes, TRUS-V1 was shown to be superior to TRUS-V2. In MRI, MRI-EV2 was more accurate than MRI-EV1. However, MRI-PV was the most accurate method. TRUS-V1 and MRI-EV2 could be used instead of MRI-PV in general clinical settings.
Jeong
Chang Wook
CW
Department of Urology, Seoul National University Hospital, Seoul, Korea.
Park
Hyoung Keun
HK
Hong
Sung Kyu
SK
Byun
Seok-Soo
SS
Lee
Hak Jong
HJ
Lee
Sang Eun
SE