MRI-TRUS Fusion Guided Prostate Biopsy - Initial Experience and Assessment of the Role of Contralateral Lobe Systematic Biopsy – Beyond the Abstract

Recently published, the results of the PRECISION trial demonstrate the superiority of MRI-targeted biopsy in comparison with standard TRUS-guided for the diagnosis of clinically significant (cs) prostate cancer (PCa): 38% vs 26%, even in the setting of the first biopsy.1 Given the high accuracy of mpMRI and MRI targeted prostate biopsy for the detection of clinically significant prostate cancer (csPCa), the importance of concurrent systematic biopsy has been questioned, as it may increase the diagnosis rate of indolent PCa, as well as the morbidity of the procedure.2
Our study on 119 patients who underwent MRI-TRUS fusion guided prostate biopsy confirms that the targeted biopsy has a higher percentage of positive biopsy cores (51% vs 29%), higher likelihood of csPCa (OR 5.36) and upgrading rate in comparison with systematic biopsy (14% vs 11.1%).3

Offering the possibility to visualize the lesion, MRI-guided biopsy is significantly correlated with exclusive targeted cores diagnosis in all patients, irrespective of initial or repeat biopsy setting, as shown in our group. The employment of mpMRI before first biopsy might reduce the number of sequential negative biopsies usually performed in patients with anterior lesions in order to confirm PCa diagnosis, as systematic biopsy targets only the peripheral zone.4

An exclusive MRI-TRUS fusion targeted cores approach would have missed 6.7% of the cases with csPCa, thus we consider that systematic biopsy might still have a role in some patients. On the other hand, performing concurrent systematic biopsy led to an absolute difference of 12.1% more clinically insignificant PCa patients diagnosed in comparison with only targeted prostate biopsy.

In an attempt to reduce the number of biopsy cores, we analyzed the cases with MRI unilateral lesion and observed that in 91.9% of them performing targeted and ipsilateral lobe systematic biopsy PCa would have led to an accurate diagnosis. The contralateral lobe biopsy could have been avoided without missing the PCa diagnosis in 75%, 88.2% and 100% of patients with PIRADS score 3, 4 and 5, respectively. Furthermore, in PIRADS score 5 lesions, the possibility to avoid in all cases the contralateral lobe systematic biopsy was independent of the initial or repeat biopsy setting.

Although considered a “blind approach” by some, the systematic prostate biopsy is still supported by urologists reporting rates of up to 18.6% csPCa missed by targeted biopsy.5
The question that raises nowadays is why we are not able to offer an accurate diagnosis of PCa based solely on MRI-targeted cores, given the already demonstrated advantages of prostate MRI. There are two types of errors that might hamper the accuracy of the diagnosis: MRI-related and biopsy-related.
First, the aggressive subtype with cribriform pattern of PCa is visible on MRI in only one third of the cases, thus these areas will not be sampled during targeted biopsies.6 Furthermore, although the PIRADS scoring system has been reassessed and is currently at version 2, there still exist interreader reproducibility and learning curve differences, with younger radiologists reporting higher PIRADS scores in almost 40% of cases.7

When considering the biopsy-targeting method, the in-bore and MRI-TRUS fusion biopsies seem to offer comparable results, both being superior to cognitive targeting.8 Still, the difference between the in-bore and MRI-TRUS fusion systems is not only related to the inherent costs, but also to the limitations of every method. Although the MRI in-bore guided prostate biopsy has the lowest needle placement error, it might show difficulty in targeting lesions located at the apex and dorsolateral segments of the prostate, which are easier targeted by a TRUS-guided approach.9

MRI-TRUS guided prostate biopsy improves the detection of csPCa and reduces the diagnosis of indolent PCa. The advent of pre-biopsy prostate MRI leads to an earlier diagnosis of anterior and transitional zone lesions, with fewer biopsies needed for an accurate diagnosis. In selected cases (PIRADS 5), the contralateral lobe systematic biopsy during MRI-TRUS fusion biopsy can safely be avoided both in initial and repeat biopsy setting. Further reduction of the biopsy cores will be possible with the increasing experience in prostate MRI and the selection of the biopsy technique with regards to lesion characteristics and location.

Written by:
Iulia Andras, MD, PhD, Iuliu Haţieganu University of Medicine and Pharmacy, Department of Urology
Emanuel Cata, Student at "Iuliu Hatieganu" University of Medicine and Pharmacy, Cluj-Napoca
Prof. Ioan Coman, MD, PhD (RO), Urology Professor, MD, PhD, Academic Vice-Rector of University of Medicine and Pharmacy “Iuliu Hatieganu” Cluj-Napoca and Head of Urological Department of Municipal Clinical Hospital and Robotic Surgery Center Cluj-Napoca, Romania 
Nicolae Crisan, MD PhD, Assist Prof, Iuliu Hatieganu University of Medicine and Pharmacy

1. Kasivisvanathan V, Rannikko AS, Borghi M, et al. MRI-Targeted or standard biopsy for prostate-cancer diagnosis. N Engl J Med 2018; 378:1767-1777
2. Bryk DJ, Llukani E, Taneja SS, Rosenkrantz AB, Huang WC, Lepor H. The role of ipsilateral and contralateral transrectal ultrasound-guided systematic prostate biopsy in men with unilateral magnetic resonance imaging lesion undergoing magnetic resonance imaging-ultrasound fusion-targeted prostate biopsy. Urology 2017;102:178-182
3. Andras I, Crisan D, Cata E, et al. MRI-TRUS fusion guided prostate biopsy - initial experience and assessment of the role of contralateral lobe systematic biopsy. Med Ultrason 2019;21(1):37-44. [epub ahead of print] doi: 10.11152/mu-1705
4. Volkin D, Turkbey B, Hoang AN, et al. Multiparametric magnetic resonance imaging (MRI) and subsequent MRI/ultrasonography fusion-guided biopsy increase the detection of anteriorly located prostate cancers. BJU Int 2014;114:E43-E49
5. Ristau BT, Chen DYT, Ellis J, et al. Defining novel and practical metrics to assess the deliverables of multiparametric magnetic resonance imaging/ultrasound fusion prostate biopsy. J Urol 2018;199:969-975
6. Truong M, Hollenberg G, Weinberg E, Messing EM, Miyamoto H, Frye TP. Impact of Gleason subtype on prostate cancer detection using multiparametric Magnetic Resonance Imaging: correlation with fnal histopathology. J Urol 2017;198:316-321
7. Cash H, Maxeiner A, Stephan C, Fischer T, Durmus T, Holzmann J, et al. The detection of significant prostate cancer is correlated with the Prostate Imaging Reporting and Data System (PI-RADS) in MRI/transrectal ultrasound fusion biopsy. World J Urol. 2016;34(4):525–32.
8. Wegelin O, van Melick HHE, Hooft L, et al. Comparing three different techniques for magnetic resonance imaging-targeted prostate biopsies: a systematic review of in-bore versus magnetic resonance imaging-transrectal ultrasound fusion versus cognitive registration. Is there a preferred technique? Eur Urol 2017;71:517-531
9. Schouten MG, van der Leest M, Pokorny M, et al. Why and where do we miss significant prostate cancer with multi-parametric magnetic resonance imaging followed by magnetic resonance-guided and transrectal ultrasound-guided biopsy in Biopsy-naïve men? Eur Urol 2017;71:896-903.

Read the Abstract