This study included a single-institution evaluation of 233 consecutive men diagnosed with prostate cancer who ultimately had a prostatectomy. These patients all had a presurgical pelvic 3T surface body coil MRI read by a fellowship-trained body radiologist, and subsequently a senior radiologist was selected to re-read all pelvic MRIs blinded to the initial interpretation. Specific to extraprostatic extension (EPE), there was low concordance comparing the primary versus repeat MRI interpretation (kappa = 0.22). Interestingly, when the senior radiologist re-read his own initial interpretation (n = 93), the kappa score for EPE was still low at 0.36. A comparison of initial MRI interpretation versus that re-read by a senior radiologist noted universal improvements in EPE parameters, including sensitivity (30.3% vs. 56.1%), specificity (80.2% vs. 88.6%), positive predictive value (PV) (37.7% vs. 66.1%), negative PV (74.4% vs. 83.6%), and accuracy (66.1% vs. 79.4%). Seminal vesicle invasion interpretation of initial MRI interpretation versus re-read yielded similar sensitivity (18.2% vs. 27.3%), specificity (97.2% vs. 93.8%), positive PV (40.0% vs. 31.6%), negative PV (91.9% vs. 92.5%), and accuracy (89.7% vs. 87.6%). The study’s strength includes a single senior radiologist re-reading all prostate MRIs, whereas a limitation of the study includes a single-center, retrospective study design.
It is crucial for our radiology colleagues to evaluate their performance reading prostate MRIs, and this study is commendable for demonstrating that even at academic medical centers, interobserver agreement may be low. As we have seen from other presentations during this session, perhaps a ‘consensus’ radiologic interpretation (with a senior radiologist) may be more reliable and should be evaluated in future prospective studies.
Presented By: Joseph C. Riney, MD, Penn State Health Milson S. Hershey Medical Center, Hershey, PA, USA
Co-Authors: Nabeel E. Sarwani, MD; Shehzad Siddique, MD; Jay D. Raman, MD
Written By: Zachary Klaassen, MD, Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre, Toronto, Ontario, Canada
at the 2017 AUA Annual Meeting - May 12 - 16, 2017 – Boston, Massachusetts, USA