Radiol Imaging Cancer 2020 Sep 25;2(5):e190078. Epub 2020 Sep 25.
Department of Radiology and Imaging Sciences (K.K.E., S.G.N.), Interventional MRI Program (K.K.E., S.G.N.), Department of Urology (C.P.F., M.G.S., A.O.O.), and Department of Pathology (A.O.O.), School of Medicine, and Winship Cancer Institute (C.P.F., M.G.S., A.O.O., S.G.N.), Emory University, 1364 Clifton Rd NE, Room BG-42, Atlanta, GA 30322; Atlanta Veterans Affairs Medical Center, Decatur, Ga (C.P.F., M.G.S.); Department of Pathology, Veterans Affairs Medical Center, Atlanta, Ga (A.O.O.); and Department of Radiology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt (K.K.E.).
Purpose: To evaluate the role of confirmatory in-bore MRI-guided biopsy in patients with low- or intermediate-risk disease diagnosed at prior transrectal US-guided biopsy and to evaluate the rate and predictors for missed cancers.
Materials And Methods: A retrospective evaluation of 50 consecutive men who had previously undergone transrectal US-guided biopsy with positive results and who underwent subsequent in-bore MRI-guided biopsy at our university hospital (average time interval, 11 months) between 2012 and 2016 was performed. Ten men were excluded because of a history of treatment after transrectal US-guided biopsy. A total of 40 men (mean age, 63 years; range, 47-84 years) were included in this study. Multiparametric 3-T MRI (T2-weighted, diffusion-weighted, and dynamic contrast material-enhanced) and transrectal in-bore MRI-guided biopsy were performed. Cancer detection, disease-grade changes, and cancers missed at in-bore MRI-guided biopsy were evaluated. Descriptive statistics were used to report different rates. The Fisher exact test was used for categoric variables. The Mann-Whitney test and independent Student test were used for nonparametric and parametric data, respectively. The McNemar test was used for paired data.
Results: The overall cancer detection rate when using in-bore MRI-guided biopsy was 65% (26 of 40). In-bore MRI-guided biopsy detected 14 previously undiscovered cancerous lesions (clinically significant cancers [CSCs], 57.1% [eight of 14]). An overall disease upgrade by in-bore MRI-guided biopsy occurred in 40% (16 of 40) of cases (61.5% [16 of 26] of cases with positive results from in-bore MRI-guided biopsy). One case was downgraded from a Gleason score (GS) of 3 + 4 = 7 to a GS of 3 + 3 = 6. Out of 71 sextant biopsies with positive results detected by transrectal US-guided biopsy (from all 40 patients), 80% (57 of 71) were visible on MR images (in-bore MRI-guided biopsy results were positive in 52.6% [30 of 57]), and 20% (14 of 71) had no image correlates on MR images. In-bore MRI-guided biopsy upgraded 60% (18 of 30) and downgraded 3.3% (one of 30) of detected lesions. The false-negative rate was 35% (14.2% [two of 14] of patients had CSCs; GS ≥ 7), was higher in prostate volumes of greater than 40 mL, and was lower in the anterior gland location ( = .04 and .01, respectively).
Conclusion: Performing confirmatory in-bore MRI-guided biopsy following positive transrectal US-guided biopsy resulted in a high disease-upgrade incidence with subsequently improved disease-risk stratification, particularly when considering patients for active surveillance or focal therapy. © RSNA, 2020See also the commentary by Weiss and Solomon in this issue.