The objective of this study was to investigate impact of prostate volume variations on prostate-specific antigen density (PSAD) and patient eligibility for active surveillance (AS).
Prostate volume and PSAD were calculated for 46 patients with prostate cancer in AS who underwent prostate magnetic resonance imaging and transrectal ultrasound (TRUS). Manual method and 2 semiautomated methods for prostate segmentation (3D-SLICER and OsiriX) were used for MR volumetry.
Magnetic resonance volumetric methods showed very good agreement (intraclass correlation coefficient, 0.98). The concordance correlation coefficient was higher among MR volumetry methods (0.971–0.998) than between TRUS and MR volumetry (0.849–0.863). The variation in PSAD estimated by TRUS versus magnetic resonance imaging was higher in large prostates (r = 0.327, P = 0.027). Transrectal ultrasonography volumetry may improperly classify 20% of patients as eligible for AS with PSAD greater than 0.15 threshold.
Although clinically used TRUS reliably estimates PSAD, it may misclassify some patients who are not eligible for AS based on PSAD criteria. Magnetic resonance–based volumetry should be considered for a more reliable PSAD calculation.
From the * The Russell H. Morgan Department of Radiology Radiological Science, The Johns Hopkins University, Baltimore, MD; † Department of Internal Medicine, Jacobi Medical Center, New York, NY; and ‡The James Buchanan Brady Urological Institute, The Johns Hopkins University, Baltimore, MD.
Received for publication February 7, 2013; accepted April 10, 2013.
Reprints: Katarzyna J. Macura, MD, PhD, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University, 601 N Caroline St, JHOC 3140C, Baltimore, MD 21287 (e-mail: firstname.lastname@example.org).
The authors declare that they have no conflicts of interest.
This work was supported by the Prostate Cancer Foundation (to Dr Carter).
Dr Macura received research funding from Siemens AG.