DOI:
Original papers
MRI-TRUS fusion guided prostate biopsy – initial experience and assessment of the role of contralateral lobe systematic biopsy
Iulia Andras
1,2, Dana Crisan
3,4, Emanuel Cata
1,2, Attila Tamas-Szora
5, Cosmin Caraiani
6, Radu-Tudor Coman
7, Catalina Bungardean
8, Claudiu Mirescu
8, Ioan Coman
1,2, Nicolae Crisan
1,21Urology Department, “Iuliu Hatieganu” University of Medicine and Pharmacy, 2Urology Department, Clinical Municipal Hospital, 3Internal Medicine Department, 5th Medical Clinic, “Iuliu Hatieganu” University of Medicine and Pharmacy, 4Internal Medicine Department, Clinical Municipal Hospital,5Radiology Department, Clinical Municipal Hospital,6Medical Imaging Department, “Iuliu Hatieganu” University of Medicine and Pharmacy, 7Epidemiology Department, “Iuliu Hatieganu” University of Medicine and Pharmacy, 8Pathology Department, Clinical Municipal Hospital, Cluj-Napoca, Romania
Received 27.08.2018 Accepted 28.11.2018 Med Ultrason
2019, Vol. 21, No 1, 37-44
Corresponding author: Assist. Prof. Dana Crisan, MD, PhD Internal Medicine Department, 5th Medical Clinic, Iuliu Hatieganu University of Medicine and Pharmacy,
8 V. Babes, 400012, Cluj-Napoca, Romania Phone: +40 741 055 464
E-mail: [email protected]
Introduction
The prostate is one of the few organs for which, in cases where the presence of cancer is suspected, the bi-
opsy is done in a nearly blind manner [1]. The systematic biopsy is performed according to the recommendations of the European Association of Urology (EAU) Guide- lines [2], with transrectal ultrasound (TRUS) guidance, either by transrectal or transperineal approach. A number of 10-12 biopsy cores are usually obtained using a prede- fined scheme to sample the whole gland [2].
TRUS allows for prostate and zonal anatomy identi- fication and biopsy guidance towards the peripheral area but has a low accuracy for the diagnosis of prostate can- cer (PCa), due its heterogenous appearance [3,4]. Less than half of the lesions visible on TRUS are confirmed as malignant at pathological assessment [5]. Therefore, Abstract
Aims: To present our initial experience and results of MRI-TRUS fusion guided prostate biopsy and assess the role of con- tralateral lobe systematic biopsy. Material and method: A number of 119 patients with clinical or biochemical suspicion for prostate cancer (PCa) were included. All patients harbored at least one PIRADS score ≥ 3 lesion and underwent MRI-TRUS fusion guided biopsy, as well as a concurrent systematic biopsy. The biopsy was performed by the same operator, using a rigid registration software system. Results: The mean age of the patients was 62.2 years. The mean pre-biopsy PSA was 9.15 ng/dl.
The diagnosis rate of MRI-TRUS fusion guided biopsy was 47% for overall PCa and 29.4% for clinically significant (cs) PCa. A higher PIRADS score was significantly associated with the presence of overall and csPCa. MRI-TRUS fusion guided biopsy had a higher percentage of positive biopsy cores (51% vs 29%), higher likelihood of csPCa (OR 5.36, p=0.008) and upgrading (14.8%) in comparison with systematic biopsy but missed 6.7% csPCa. The contralateral lobe systematic biopsy could have been avoided without losing the PCa diagnosis all patients with PIRADS score 5, both in initial and repeat biopsy setting. Anterior and transitional lesions were more likely to be diagnosed only by targeted cores. Conclusion: MRI-TRUS guided prostate biopsy improves the detection of PCa, but systematic biopsy is still essential. In selected cases (PIRADS 5), contralateral lobe systematic biopsy can safely be avoided. Pre-biopsy mpMRI might reduce the number of biopsy sessions in patients with anterior and transitional lesions.
Keywords: image-guided biopsy; magnetic resonance imaging; prostate cancer
DOI: 10.11152/mu-1705
the systematic TRUS-guided prostate biopsy associates a high rate of underdiagnosis of aggressive PCa, but also overdiagnosis of indolent PCa [6].
As a result, multiparametric magnetic resonance im- aging (mpMRI) has become the new standard imaging evaluation for the initial diagnosis of PCa [7], ensuring a detection rate as high as 93% for Gleason score >7 PCa [8], albeit for the time being the EAU Guidelines recom- mend its use only in the setting of a prior negative pros- tate biopsy and persistent suspicion of PCa [2].
Due to the possibility of the identification of PCa, mpMRI is an important tool for performing targeted bi- opsies from visible abnormal areas inside the prostate.
Three techniques have been developed in order to assist a targeted prostate biopsy [9]: cognitive, in-bore and MRI- TRUS fusion guided. Cognitive MRI-guided biopsy in- volves that the operator mentally superimposes the le- sion seen on mpMRI onto the ultrasound examination, whereas in-bore guided biopsy allows for exact needle positioning and biopsy inside the MRI gantry during sequential scans. The MRI-TRUS fusion guided biopsy employs a software which overlaps the contouring of the lesion from the MRI images onto the ultrasound in real- time, thus allowing a targeted biopsy [10].
Recently published, the results of the PRECISION trial demonstrate the superiority of MRI-targeted bi- opsy in comparison with standard TRUS-guided for the diagnosis of clinically significant (cs)PCa (38% vs 26%, respectively, p=0.005) even in the setting of first biopsy [11]. Moreover, in-bore guided prostate biopsy has shown a superior PCa detection rate in comparison with cognitive biopsy, but a similar diagnostic yield with MRI-TRUS fusion guided biopsy [12]. Current literature does not show a clear superiority of one technique over the other [2]. The long duration and high costs of pro- cedure, but also the need for magnetic field compatible devices hamper the use of in-bore MRI guided biopsy [13]. On the other hand, MRI-TRUS fusion guided pros- tate biopsy combines the advantages of TRUS and MRI, by ensuring increased patient comfort, lower costs, as well as real-time lesion visualization and guidance of the biopsy [14].
Given the high accuracy of mpMRI and MRI-TRUS fusion guided prostate biopsy for the detection of csPCa, the importance of concurrent systematic biopsy has been questioned, as it may increase the diagnosis rate of indo- lent PCa, as well as the morbidity of the procedure [15].
The objective of the current study was to present our initial experience and results of MRI-TRUS fusion guid- ed prostate biopsy. A secondary objective of our study was to assess the role of concurrent contralateral lobe systematic biopsy.
Material and methods
We conducted a prospective cohort study in which we included a number of 119 patients who presented to our department for the clinical or biochemical suspicion of PCa and harbored at least a Prostate Imaging Reporting and Data System (PIRADS) score ≥3 lesion seen on pre- biopsy mpMRI. The criteria for the indication of mpMRI prior to first biopsy were as follows: patients age below 70 years and PSA below 15 ng/ml. For patients in repeat biopsy setting no maximum cut-off value was used for age or PSA in order to select the patients who underwent MRI prior to targeted biopsy, as these patients have a clear indication for imaging assessment according to the EAU Guidelines [2].
The mpMRI were performed using a 1.5T system (MAGNETOM Aera®; Siemens Healthcare, Erlan- gen, Germany) coupled with a 16-channel phased-array body coil (Siemens Healthcare). On the evening prior to the examination the patients self-administered a bowel preparation solution (FORTRANS®, 1 liter reconstituted solution for each 20 kg of body mass). Prior to the MRI examination, drotaverin was administered i.v. (No-Spa, 40 mg/2ml). The following non-contrast sequences were acquired: axial T2WI, sagittal T2WI, coronal T2WI, ax- ial T1WI, axial diffusion-weighted imaging (DWI), (Ta- ble I). An unenhanced axial T1 VIBE sequence acquisi- tion was performed and was followed by additional axial T1 VIBE scans after contrast administration. Diffusion- weighted MRI was performed with measured b values of 50, 400, 800, 1000, 1500 and the image software auto- matically calculated apparent diffusion coefficient maps (ADC). Afterwards, the contrast agent gadobutrol (Ga- dovist® 1.0; Bayer Schering Pharma AG, Berlin, Ger- many) was administered employing the free-hand tech- nique, using a dose of 0.1 mmol/ kg−1. Dynamic contrast enhanced axial 3D T1WI were immediately acquired after contrast administration. The MRI studies were re- viewed by 2 experienced radiologists (more than 5 years of experience) using the PIRADS v2 system and the cor- responding anatomic division diagram to illustrate the location of the lesion [16]. The radiologists were aware of the clinical information of all patients.
The MRI-TRUS fusion guided biopsy was performed by the same operator (urologist) in an outpatient setting, using local anaesthesia with lidocaine gel instilled en- dorectally, by transrectal approach, with the patient po- sitioned in left lateral decubitus. Prior to this study, the urologist had performed 30 MRI-TRUS fusion guided prostate biopsies and more than 150 TRUS-guided sys- tematic biopsies. All biopsies were performed using the Arietta 70a system (Hitachi, Japan) with endfire endorec-
tal probe C41V1 2-10 mHz, RVS software and rigid registration, using sagittal and axial T2WImpMRI se- quences. The biopsy was performed in the sagittal TRUS plane (fig 1). A number of 1-3 biopsies/lesion along with 12 systematic cores were obtained in all patients. The suspicious areas were biopsied at the beginning of the procedure in order to avoid errors of registration due to prostate swelling. The systematic biopsy was performed by the same operator as MRI-TRUS fusion biopsy, being aware of the MRI results. All biopsies were reviewed by the same 2 experienced pathologists. Any prostate cancer with a Gleason score ≥7(3+4)/ ISUP (International Soci- ety of Urological Pathology) grade 2 was considered a clinically significant disease.
All patients signed the informed consent according to the World Medical Association Declaration of Helsin- ki, revised in 2000. The study was approved by the local Ethical Committee.
Statistical analysis
The statistical analysis was performed using Med- calc v.12.4 (MedCalc Software bvba, Ostend, Belgium;
https://www.medcalc.org). The difference between two
means was analyzed by the Independent Sample T-test.
Chi-square test was used for the correlation between categorical variables, and ANOVA for the correlation between categorical and continuous variables. The di- agnostic accuracy was assessed by Receiver Operating Curve (ROC) analysis and expressed using sensitivity (Se), specificity (Sp) and area under the curve (AUC).
p<0.05 was considered statistically significant.
Results Study group
The mean age of the patients was 62.2 years (range:
46-78 years) and the mean pre-biopsy PSA was 9.15 ng/
dl (range: 1.8-70 ng/dl). Fourteen patients (16.8%) had a history of at least one negative prostate biopsy. Twen- ty-nine (24.3%) patients had multiple lesions (≥2) on mpMRI. The mean number of total biopsy cores was 14 (range: 13-16) and the mean number of targeted cores was 2 (range: 1-4).
Characteristics of PCa patients
Prostate cancer was diagnosed in 47% of cases (55 patients) whereas atypical small acinar proliferation/
high-grade intraepithelial neoplasia (ASAP/HGPIN) were present in 6.8% of patients. Clinically significant disease was identified in 29.4% of all patients included in the study.
The presence of multiple lesions on MRI was not cor- related with a higher rate of overall or csPCa diagnosis (p=0.7 and p=0.4, respectively).
The PIRADS score was significantly associated with the presence of PCa, p<0.0001, with an AUC of 0.805 (95% CI: 0.71 – 0.87, p<0.01) for the detection of overall PCa in lesions with PIRADS score 4 and 5. If PIRADS 4 would have been used as a cut-off for selecting patients for biopsy, in 29 cases a prostate biopsy could have been avoided (p<0.0001).
Clinically significant disease was present in 35 (64.8%) of the patients diagnosed with PCa and was cor- Fig 1. A 60-year-old patient with a PSA of 5.8 ng/ml and a
PIRADS score 3 lesion at the base of the right prostate lobe.
An MRI-TRUS fusion biopsy was performed and confirmed the diagnosis of PCa Gleason score 7(3+4), with 1/2 and 4/12 positive targeted and systematic cores, respectively.
Table I. Multiparametric MRI examination specifications Pulse
sequence Plane TR (ms) TE
(ms) Flip angle
(degrees) Slice thick-
ness (mm) Matrix
size Field of
view (mm) Time
T2 TSE Sagittal 4960 73 161 3 256x320 220 3m5s
T2 TSE Coronal 7430 108 160 3 298x320 200 4m36s
T2 TSE Axial 4330 84 156 3 266x320 200 4m56s
T1 TSE Axial 587 22 177 3 266x320 200 3m6s
DWI Axial 4700 77 3 112x112 200 6m41s
T1 VIBE
fat sat Axial 4.46 1.72 12 3 154x192 260 8s precontrast acquisition and
3m22s postcontrast evaluation TR = repetition time; TE = echo time; TSE = turbo-spin echo; DWI = diffusion weighted imaging; VIBE = spoiled 3D generic gradient echo;
ms = miliseconds
related with a higher PIRADS score, p=0.02 (Table II).
The presence of a PIRADS score 5 lesion had a Se of 57.14%, Sp 90.5% and AUC of 0.738 (95% CI: 0.64- 0.81) for the presence of csPCa, p<0.0001.
MRI-TRUS fusion guided vs systematic prostate biopsy
Of the patients with PCa (n=55), 35.8% were di- agnosed only on systematic cores, 7.5% only on MRI- TRUS fusion guided biopsy cores, whereas 56.6% had both systematic and targeted positive cores.
The presence of an anterior or transitional zone lesion was significantly correlated with PCa diagnosis only on targeted biopsy cores in all patients (p=0.02).
Patients in the repeat biopsy setting showed a higher percentage of lesions located in the anterior and transi- tional areas in comparison with patients at initial biopsy and a higher exclusive diagnosis yield by MRI-TRUS fu- sion biopsy (25% vs 4.4%, Table III).
The overall percentage of positive biopsy cores (PBC) of the total number, systematic and targeted cores was 32%, 29% and 51%, respectively (p=0.0012).
More than half of the patients (57.9%, n=19) diag- nosed only on systematic cores harbored clinically insig- nificant PCa, as well as 4 patients diagnosed exclusively on MRI-TRUS fusion biopsy cores. Performing con- current systematic biopsy led to an absolute difference of 12.1% more clinically insignificant PCa patients di- agnosed in comparison with MRI-TRUS fusion guided prostate biopsy (32.7% vs 20.6%).
A csPCa was 5 times more likely to be diagnosed by MRI-TRUS fusion guided biopsy cores than systematic biopsy (OR 5.36, p=0.008) (Table IV). In 14.8% of cases (n=55) an upgrading to a higher Gleason score was found by MRI-TRUS fusion guided cores, in comparison with 11.1% by systematic biopsies. A number of 8/119 patients (6.7%) harbored csPCa but had negative MRI-TRUS
Table II. Diagnostic yield of MRI-TRUS fusion biopsy for overall and clinically significant prostate cancer depending on PIRADS score
PCa patients/all patients with the same
PIRADS score x 100 csPCa patients/all patients with the same
PIRADS score x 100 NPV for csPCa
PIRADS 3 17.1 5.7 55.4
PIRADS 4 52.2 27.7 64.5
PIRADS 5 92.6 74.1 81.7
All results are expressed in percentages. cs = clinically significant; PCa = prostate cancer; PIRADS = prostate imaging reporting and data system; NPV = negative predictive value
Table III. Comparison of prostate cancer diagnosis rates between initial and repeat biopsy setting
Initial biopsy setting Repeat biopsy setting p
PIRADS score 3 33.3
41.125.6
26.352.6
21.1 0.6
45
mpMRI lesion location Base 15.9
49.219 12.73.2
2533.3 0 25 16.7 Midgland 0.09
ApexTransitional Anterior
Overall PCa diagnosis rate 48.5 40 0.6
csPCa diagnosis rate 30 25 0.6
PCa diagnosis only on targeted cores 4.4 25 0.04
PCa diagnosis only on systematic cores 35.6 37.5 0.9
PCa diagnosis both on systematic and targeted cores 60 37.5 0.2
ISUP grade 1 34.8
47.813 2.22.2
37.5 37.5 12.5 12.5 - 2 0.6
34
Percentage of patients in whom the contralateral lobe biopsy did not 5
change the management 93.5 83.3 0.4
All results are expressed in percentages. cs = clinically significant; mpMRI = multiparametric magnetic resonance imaging; PCa = prostate cancer; ISUP = International Society of Urological Pathology; PIRADS = prostate imaging reporting and data system
fusion biopsy, in comparison with 1.6% (2/119 cases) csPCa with negative systematic biopsy, thus showing a higher sensitivity for the systematic biopsy.
Positive targeted biopsy cores had a higher percent- age of mean PCa tissue length (55%, range:10-100%) and maximum PCa tissue length (68.7%, range: 0%- 100%) in comparison with positive systematic biopsy cores - 47.2% (range: 7-94%) and 63% (range: 0%- 100%), respectively, p=0.1.
In 91.9% of cases with MRI unilateral lesion (n=89 patients), PCa diagnosis would have been correctly identified if the systematic biopsy would have been per- formed only on the ipsilateral prostate lobe. A single pa- tient with csPCa would have been missed if contralateral systematic biopsy would not have been performed. The contralateral lobe biopsy could have been avoided with- out losing the PCa diagnosis in 75%, 88.2% and 100% of patients with PIRADS score 3, 4 and 5, respectively. In PIRADS score 5 lesions, the possibility of avoiding in all cases the contralateral lobe systematic biopsy was inde- pendent of the initial or repeat biopsy setting.
Discussions
The results of our study confirm the already known importance of mpMRI and MRI-TRUS fusion guided prostate biopsy for the diagnosis of PCa. Similar overall and csPCa diagnosis rates have been reported by several centers [17-19]. A higher PIRADS score is significantly correlated with the presence of clinically significant dis- ease. Performing MRI-TRUS fusion biopsy ensures a higher percentage of positive biopsy cores, higher can- cer tissue length and a higher probability for diagnosing aggressive PCa, even from the beginning of the learn- ing curve, as confirmed also by the systematic review of Wegelin et al [12]. In our study, the presence of multi- ple lesions on mpMRI was not predictive for overall or csPCa detection, similar to the conclusion of Patel et al [20].
Adding targeted cores to the systematic biopsy up to a median total of 14 cores does not result in higher pain or
discomfort as reported by Robins et al in a group of 170 patients who underwent prostate biopsy [21].
One issue that merits further discussion is the type of registration employed during MRI-TRUS fusion biopsy which may account for errors of targeting. Rigid regis- tration systems overlap the MRI and TRUS volumes, without taking into consideration a possible prostate de- formation and lesion displacement [22], whereas elastic registration systems compensate for the deformation of the prostate due to patient positioning, endorectal coil or TRUS probe insertion [23]. A systematic review per- formed by Venderink et al [24] on 10 studies including a total of 3916 patients concluded that elastic registration has a higher csPCa detection rate (34.59%) in compari- son with rigid registration (25.19%), albeit the difference is not statistically significant (p=0.83), possibly due to cognitive compensation of deformation performed by the operator. In our experience, using a rigid registration system for MRI-TRUS fusion guided prostate biopsy en- sured a csPCa detection rate of 29.4%.
Although it associated a higher rate of indolent PCa, the systematic biopsy upgraded in our study only 11% of cases to a higher Gleason score. One possible explana- tion for the high cancer diagnosis accuracy of systematic biopsy in our study is that the operator was not blinded to the mpMRI results, so the location of the standard cores might have been biased by the information, thus repre- senting a limitation of the current study. A percentage of 6.7% of csPCa patients were missed by MRI-TRUS fusion biopsy, but other authors reported a rate as high as 18.6% of csPCa missed by targeted biopsy [25], thus supporting the role of concurrent systematic biopsy. Fur- thermore, Borkowetz et al [26] assessed the concordance between the Gleason score of MRI-TRUS fusion biop- sy and prostatectomy specimen and concluded that the combination of targeted and systematic cores ensures the highest accuracy (63% MRI-TRUS fusion vs 54% sys- tematic vs 75% combination).
In order to decrease the diagnosis of indolent PCa, the role of contralateral prostate lobe biopsy has been inves- tigated. Lepor et al [15] showed that avoidance of con- Table IV. Diagnostic yield of MRI-TRUS fusion and systematic biopsy with regards to International Society of Urological Pathology grading (ISUP)
ISUP grade Diagnostic yield of MRI-TRUS fusion biopsy Diagnostic yield of systematic biopsy
1 22.9 34
2 57.1 46
3 14.3 14
4 2.9 4
5 2.9 2
All results are expressed in percentages.
tralateral biopsy associates a rate of 18.6% of less indo- lent PCa diagnosed and 4% missed csPCa, so in selected cases targeted plus ipsilateral systematic biopsy might be sufficient for an accurate diagnosis. Our results confirm that for lesions with PIRADS score of 5, contralateral bi- opsy could be safely avoided both in the initial and repeat biopsy setting.
The location of the lesion is also important when per- forming prostate biopsy. The systematic cores sample the most posterior and peripheral part of the prostate, where- as lesions located anteriorly might be missed [27]. Of- fering the possibility to visualize the lesion, MRI-TRUS fusion biopsy is significantly correlated with exclusive targeted cores diagnosis in all patients, irrespective of initial or repeat biopsy setting, as shown in our group. As a result, employment of mpMRI before the first biopsy might reduce the number of sequential negative biopsies usually performed in patients with anterior lesions in order to confirm the PCa diagnosis [28]. In the present study, patients with a history of previous negative biopsy had a higher probability of an anterior located lesion and MRI-TRUS fusion targeted cores showed a higher diag- nostic yield in these cases (25% repeat biopsy vs 4% ini- tial biopsy setting, p=0.04).
A number of studies aimed to compare the different types of targeted biopsy in terms of cancer diagnosis rates, but significant results are still awaited [29]. Prob- ably the correct question is not which technique is best, but which technique is best for which patient.
As concluded by the PRECISION trial [11], any type of MRI targeted biopsy is superior to systematic TRUS for the detection of csPCa, thus at least cognitive pros- tate biopsy should be performed in all centers. This rec- ommendation is indirectly supported also by our study, showing a high accuracy of systematic biopsy due to the bias caused by the lack of operator blinding to the pre- biopsy mpMRI. If available, a more accurate targeted technique (MRI-TRUS fusion or in-bore) should be em- ployed, as cognitive biopsy is hampered by operator’s expertise and spatial cognition [10].
Wegelin et al [12] showed that MRI-TRUS fusion guided biopsy is similar with in-bore guided biopsy for the diagnosis of csPCa, but more recent studies support the superiority of in-bore guided biopsy in comparison with other types of targeting. Still, in-bore guided prostate biopsy is hampered by increased costs (due to the need of sequential scanning and magnetic field-compatible de- vices), a longer time of the procedure, increased patient discomfort and less availability [13]. Thus, taking into consideration the practical advantages of MRI-TRUS fusion systems in comparison with in-bore it is only logical to recommend MRI in-bore biopsy exclusively
in cases in which MRI-TRUS fusion biopsy misses the target.
The dimension of the lesion is important due to the inherent needle placement error, which is the lowest in MRI in-bore biopsy (2.5 mm [30] vs 3.5mm for MRI- TRUS fusion with elastic registration [31]). Rigid reg- istration might increase the needle placement error dur- ing MRI-TRUS fusion biopsy, thus lesions with a radius smaller than 5 mm would be better targeted by in-bore biopsy.
As shown by Porpiglia et al [32], MRI inhomogenous lesions suggest a Gleason score heterogeneity so they re- quire the most exact targeting of the center of the lesion in order to have an accurate diagnosis of Gleason score.
Therefore, if difficulty in the targeting of the lesion is predicted for MRI-TRUS fusion biopsy, MRI in-bore bi- opsy should be recommended.
Furthermore, Westhoff et al [31] showed that al- though elastic image registration ensures a more precise targeting in comparison with rigid registration during MRI-TRUS fusion biopsy, it still has a low accuracy for the diagnosis of lesions located at the base (vs transi- tional and anterior zones) and for small volume prostates (below 50 ml).
Therefore, MRI-TRUS fusion prostate biopsy should be performed in all cases, except patients with small prostates and small heterogenous basal lesions, who should be reserved for in-bore MRI biopsy.
Although mpMRI has significantly impacted the PCa diagnosis, its accuracy is still hampered by the lack of visibility of specific lesions. Cribriform pattern PCa is a very aggressive subtype of prostate adenocarcinoma, that is associated with poor prognosis and worse cancer- specific survival, but the accuracy of mpMRI for the de- tection of these lesions is low – 36% [33-35]. Truong et al assessed the performance of prostate biopsy in the detec- tion of cribriform PCa and concluded that the combina- tion of MRI-TRUS fusion and systematic prostate biopsy has the highest sensitivity for the diagnosis of this mor- phological subtype in comparison with either technique alone: 37.1% vs 28.6% for targeted biopsy and 20.7% for systematic [36]. Still, the accuracy is rather poor.
The relatively low number of patients, which might impair the statistical results and the availability of mpM- RI information for the urologist who performed the sys- tematic biopsy, leading to higher accuracy than standard, could be considered the limitations of the current study.
Conclusions
MRI-TRUS guided prostate biopsy improves the de- tection of PCa by a higher percentage of positive biopsy
cores, higher cancer tissue length and higher likelihood of csPCa detection, lower yield of indolent PCa and the possibility to diagnose anterior and transitional zone le- sions, but systematic biopsy is still essential. An anterior or transitional lesion will most probably be diagnosed only by targeted biopsy cores. In highly selected cases (PIRADS 5), contralateral lobe systematic biopsy during MRI-TRUS fusion biopsy can safely be avoided both in an initial and repeat biopsy setting. In order to ensure the best results, clear indications for every MRI-targeting method for prostate biopsy should be established.
Conflict of interest: none References
1. Boesen L, Nørgaard N, Løgager V, Balslev I, Thomsen HS.
Where do transrectal ultrasound- and Magnetic Resonance Imaging-guided biopsies miss significant prostate cancer?
Urology 2017;110:154-160.
2. Mottet N, Bellmunt J, Bolla M, et al. EAU-ESTRO-SIOG Guidelines on Prostate Cancer. Part 1: Screening, diag- nosis, and local treatment with curative intent. Eur Urol 2017;71:618-629.
3. Ghai S, Toi A. Role of transrectal ultrasonography in pros- tate cancer. Radiol Clin North Am 2012;50:1061-1073.
4. Dudea SM, Giurgiu CR, Dumitriu D, et al. Value of ultra- sound elastography in the diagnosis and management of prostate carcinoma. Med Ultrason 2011;13:45-53.
5. Dyke CH, Toi A, Sweet JM. Value of random ultra- sound-guided transrectal prostate biopsy. Radiology 1990;176:345–349.
6. Sugano D, Sidana A, Calio B, Cobb K, Turkbey B, Pinto PA. MRI-targeted biopsy: is systematic biopsy obsolete?
Can J Urol 2017;24:8876-8882.
7. Ahmed HU, El-Shater Bosaily A, Brown LC, et al. Diag- nostic accuracy of multi-parametric MRI and TRUS biopsy in prostate cancer (PROMIS): a paired validating confirma- tory study. Lancet 2017;389:815-822.
8. Bratan F, Niaf E, Melodelima C, et al. Influence of imag- ing and histological factors on prostate cancer detection and localisation on multiparametric MRI: a prospective study.
Eur Radiol 2013;23:2019-2029.
9. Grummet J. How to biopsy: transperineal versus transrec- tal, saturation versus targeted, what’s the evidence? Urol Clin North Am 2017;44:525-534.
10. Cool DW, Zhang X, Romagnoli C, Izawa JI, Romano WM, Fenster A. Evaluation of MRI-TRUS fusion versus cogni- tive registration accuracy for MRI-targeted, TRUS-guided prostate biopsy. AJR Am J Roentgenol 2015;204:83-91.
11. 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.
12. 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.
13. Warlick C, Futterer J, Maruf M, et al. Beyond transrectal ultrasound-guided prostate biopsies: available techniques and approaches. World J Urol 2018, doi:10.1007/s00345- 018-2374-8.
14. Das CJ, Razik A, Sharma S. Magnetic resonance imaging- transrectal ultrasound fusion biopsy of the prostate- an up- date. Semin Roentgenol 2018;53:219-226.
15. Bryk DJ, Llukani E, Taneja SS, Rosenkrantz AB, Huang WC, Lepor H. The role of ipsilateral and contralateral tran- srectal ultrasound-guided systematic prostate biopsy in men with unilateral magnetic resonance imaging lesion un- dergoing magnetic resonance imaging-ultrasound fusion- targeted prostate biopsy. Urology 2017;102:178-182.
16. Weinreb JC, Barentsz JO, Choyke PL, et al. PI-RADS Pros- tate Imaging – Reporting and Data System: 2015, Version 2. Eur Urol 2016;69:16-40.
17. Sathianathen NJ, Konety BR, Soubra A, et al. Which scores need a core? An evaluation of MR-targeted biopsy yield by PIRADS score across different biopsy indications. Prostate Cancer Prostatic Dis 2018, doi:10.1038/s41391-018-0065- 18. 6.Pepe P, Garufi A, Priolo G, Pennisi M. Transperineal Versus
transrectal MRI/TRUS fusion targeted biopsy: detection rate of clinically significant prostate cancer. Clin Genitou- rin Cancer 2017;15:e33-e36.
19. Hofbauer SL, Maxeiner A, Kittner B, et al. Validation of Prostate Imaging Reporting and Data Systemversion 2 for the detection of prostate cancer. J Urol 2018;200:767-773.
20. Patel N, Halpern JA, Kasabwala K, et al. Multiple Regions of Interest on multiparametric magnetic resonance imag- ing are not associated with increased detection of clini- cally significant prostate cancer on fusion biopsy. J Urol 2018;200:559-563.
21. Robins D, Lipsky M, RoyChoudry A, Wenske S. Assess- ment of discomfort and pain in patients undergoing fusion magnetic resonance imaging-guided vs TRUS-guided pros- tate biopsy. Urology 2018;116:30-34.
22. Delongchamps NB, Peyromaure M, Schull A, et al. Prebi- opsy magnetic resonance imaging and prostate cancer de- tection: comparison of random and targeted biopsies. J Urol 2013;189:493–499.
23. Logan JK, Rais-Bahrami S, Turkbey B, et al. Current status of magnetic resonance imaging (MRI) and ultrasonography fusion software platforms for guidance of prostate biopsies.
BJU Int 2014;114:641–652.
24. Venderink W, de Rooij M, Sedelaar JPM, Huisman HJ, Füt- terer JJ. Elastic versus rigid image registration in magnetic resonance imaging-transrectal ultrasound fusion prostate biopsy: a systematic review and meta-analysis. Eur Urol Focus 2018;4:219-227.
25. Ristau BT, Chen DYT, Ellis J, et al. Defining novel and practical metrics to assess the deliverables of multiparamet- ric magnetic resonance imaging/ultrasound fusion prostate biopsy. J Urol 2018;199:969-975.
26. Borkowetz A, Platzek I, Toma M, et al. Direct comparison of multiparametric magnetic resonance imaging (MRI) re- sults with final histopathology in patients with proven pros- tate cancer in MRI/ultrasonography-fusion biopsy. BJU Int 2016;118:213-220.
27. 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 mag- netic resonance-guided and transrectal ultrasound-guided biopsy in Bbiopsy-naïve men? Eur Urol 2017;71:896-903.
28. 28.Volkin D, Turkbey B, Hoang AN, et al. Multiparamet- ric 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.
29. Giganti F, Moore CM. A critical comparison of techniques for MRI-targeted biopsy of the prostate. Transl Androl Urol 2017;6:432-443.
30. Xu H, Lasso A, Guion P, et al. Accuracy analysis in MRI- guided robotic prostate biopsy. Int J Comput Assist Radiol Surg 2013;8:937-944.
31. Westhoff N, Siegel FP, Hausmann D, et al. Precision of MRI/ultrasound-fusion biopsy in prostate cancer diagnosis:
an ex vivo comparison of alternative biopsy techniques on prostate phantoms. World J Urol 2017;35:1015-1022.
32. Porpiglia F, De Luca S, Passera R, et al. Multiparametric magnetic resonance/ultrasound fusion prostate biopsy:
number and spatial distribution of cores for better index tu- mor detection and characterization. J Urol 2017;198:58-64.
33. Bălăcescu L, Bălăcescu O, Crişan N, et al. Identifying mo- lecular features for prostate cancer with Gleason 7 based on microarray gene expression profiles. Rom J Morphol Em- bryol 2011;52:1195-1202.
34. Kweldam CF, Kummerlin IP, Nieboer D, et al. Disease- specific survival of patients with invasive cribriform and intraductal prostate cancer atdiagnostic biopsy. Mod Pathol 2016;29: 630-636.
35. Truong M, Hollenberg G, Weinberg E, Messing EM, Miy- amoto H, Frye TP. Impact of Gleason subtype on prostate cancer detection using multiparametric Magnetic Reso- nance Imaging: correlation with final histopathology. J Urol 2017;198:316-321.
36. Truong M, Feng C, Hollenberg G, et al. A comprehensive analysis of cribriform morphology on magnetic resonance imaging/ultrasound fusion biopsy correlated with radical prostatectomy specimens. J Urol 2018;199:106-113.
