High concordance of findings obtained from in-gantry transgluteal MRI- and TRUS-guided biopsy as compared to prostatectomy specimens

To determine the utility of our transgluteal MRI-guided prostate biopsy approach.

960 biopsy series taken within the period of one year were evaluated including 301 MRI-guided and 659 TRUS-guided biopsies.

The positivity rate and the fraction of high-grade cancers were significantly higher in MRI-guided than in TRUS biopsies. 65.4% of 301 MRI-guided and 57.2% of 659 TRUS biopsies contained cancer (p=0.0157). A Gleason 3+3=6 was seen in 16.8% of 197 MRI-guided and 36.1% of 377 TRUS biopsies (p<0.0001). There was also a markedly higher quantity of cancer tissues in MRI-guided biopsies. In all cancers, the average cancer surface on biopsies was 64.8 ± 51.6 mm(2) in MRI-guided biopsies as compared to 23.0 ± 31.4 mm(2) in non-MRI-guided biopsies (p<0.0001). With respect to the tissue quantity, superiority of MRI-guided biopsy was highest in Gleason 3+3=6 cancers (20.9 ± 27.9 vs. 5.1 ± 10.2 mm(2) ; p<0.0001) and in Gleason 3+4=7 cancers (59.7 ± 38.0 vs. 17.7 ± 18.4 mm(2) ; p<0.0001). A comparison of biopsy Gleason grades with findings in prostatectomies could be done in 80 patients with MRI-guided and 170 patients with non-MRI-guided biopsies and revealed a very high but almost identical concordance of TRUS and MRI-guided biopsies with prostatectomy results. With both approaches, undetected high-risk cancers were present in about 10% of patients with low-risk biopsy results. A significant difference was seen, however, in the fraction of patients that had clinically insignificant cancers and were operated. The fraction of patients having a Gleason 3+3=6 carcinoma in their prostatectomy was 11.2% in the post TRUS biopsy cohort but only 2.5% in the post MRI biopsy cohort (p=0.0211).

MRI-guided transgluteal prostate biopsy has a high detection rate for high-risk carcinomas while the risk of detecting clinically insignificant carcinomas appears to be reduced. This may by itself lead to a reduction of unnecessary prostatectomies. Overtreatment may be further avoided by better applicability of molecular testing to MRI-guided biopsies due to the excessive amount of tissue available for analysis especially in patients with potential low-risk carcinomas. This article is protected by copyright. All rights reserved.

BJU international. 2017 Mar 13 [Epub ahead of print]

Stefan Steurer, Sebastian Dwertmann Rico, Ronald Simon, Sarah Minner, Maria Christina Tsourlakis, Till Krech, Christina Koop, Markus Graefen, Hans Heinzer, Meike Adam, Hartwig Huland, Thorsten Schlomm, Guido Sauter, Agron Lumiani

Institute of Pathology, University Medical Centre Hamburg-Eppendorf, Germany., Martini Clinic Prostate Cancer Centre, University Medical Centre Hamburg-Eppendorf, Germany., ALTA Clinic GmbH, Gütersloh, Germany.