PURPOSE: To determine whether focal peripheral zone enhancement on routine venous-phase CT is predictive of higher-grade (Gleason 4 + 3 and higher) prostate cancer.
MATERIALS AND METHODS: IRB approval was obtained and informed consent waived for this HIPAA-compliant retrospective study. Forty-three patients with higher-grade prostate cancer (≥Gleason 4 + 3) and 96 with histology-confirmed lower-grade (≤ Gleason 3 + 4 (n = 47)) or absent (n = 49) prostate cancer imaged with venous-phase CT comprised the study population. CT images were reviewed by ten blinded radiologists (5 attendings, 5 residents) who scored peripheral zone enhancement on a scale of 1 (benign) to 5 (malignant). Mass-like peripheral zone enhancement was considered malignant. Likelihood ratios (LR) and specificities were calculated. Multivariate conditional logistic regression analyses were conducted.
RESULTS: Scores of "5" were strongly predictive of higher-grade prostate cancer (pooled LR+ 9.6 (95% CI 5.8-15.8)) with rare false positives (pooled specificity: 0.98 (942/960, 95% CI 0.98-0.99); all 10 readers had specificity ≥95%). Attending scores of "5" were more predictive than resident scores of "5" (LR+: 14.7 (95% CI 5.8-37.2) vs. 7.6 (95% CI 4.2-13.7)) with similar specificity (0.99 (475/480, 95% CI 0.98-1.00) vs. 0.97 (467/480, 95% CI 0.96-0.99)). Significant predictors of an assigned score of "5" included presence of a peripheral zone mass (p < 0.0001), larger size (p < 0.0001), and less reader experience (p = 0.0008). Significant predictors of higher-grade prostate cancer included presence of a peripheral zone mass (p = 0.0002) and larger size (p < 0.0001).
CONCLUSION: Focal mass-like peripheral zone enhancement on routine venous-phase CT is specific and predictive of higher-grade (Gleason 4 + 3 and higher) prostate cancer.
Glazer DI, Davenport MS, Khalatbari S, Cohan RH, Ellis JH, Caoili EM, Stein EB, Childress JC, Masch WR, Brown JM, Mollard BJ, Montgomery JS, Palapattu GS, Francis IR. Are you the author?
Department of Radiology, University of Michigan Health System, B2-A209P, Ann Arbor, MI, 48109, USA.
Reference: Abdom Imaging. 2014 Sep 6. Epub ahead of print.