Anterior Localization of Prostate Cancer Suspicious Lesions in 1,161 Patients Undergoing Magnetic Resonance Imaging/Ultrasound Fusion Guided Targeted Biopsies

Does a large prostate size, small lesion volume, or long needle distance from the probe to the lesion reduce magnetic resonance imaging-targeted cancer detection?

Background

We aimed to evaluate whether large prostate size, small lesion volume, or long lesion distance from the ultrasound probe tip would decrease cancer detection in transrectal magnetic resonance imaging (MRI)-targeted biopsies.

Materials and methods

Patients who underwent MRI-targeted biopsy at our institution between May 2017 and August 2019 were enrolled in a prospective database. Three to 5 cores were obtained from ≥2 prostate imaging reporting and data system v2 lesions. A multivariable model was created that included needle distance to the lesion, prostate specific antigen, prostate imaging reporting and data system, lesion volume, and prostate volume.

Results

A total of 377 patients with 533 lesions underwent a biopsy during the study period. A total of 233 (44%) lesions were positive for prostate cancer, and 173 (32%) lesions had clinically significant prostate cancer. The mean needle distance to the lesion was 11.7 mm (interquartile range, 7.6-15.5 mm). The likelihood of obtaining a positive core on biopsy decreased as the distance from the ultrasound probe increased for all prostate cancers and clinically significant prostate cancer (p = 0.018 and p = 0.004, respectively). Every 10 mm from the rectum, there was an 8%-10% decrease in the rate of cancer detection. Similarly, as the prostate volume increased, the odds of obtaining a positive core also decreased (p = 0.039). There was no significant association between the lesion size and amount of cancer obtained on biopsy.

Conclusions

Our data showed that transrectal MRI-targeted biopsy cancer detection modestly decreased the lesion from the ultrasound probe and with a large prostate volume but could not prove that lesion volume was a significant predictor of the amount of cancer detected.

Clinicopathologic Significance of Anterior Prostate Cancer: Comparison With Posterior Prostate Cancer in the Era of Multiparametric Magnetic Resonance Imaging

Anterior prostate cancer (APC) has been considered an indolent tumor, most commonly arising in the transition zone (TZ). More recently, detection of APC has been facilitated through multiparametric magnetic resonance imaging and improved biopsy techniques, enabling earlier detection. The pathologic features and clinical significance of pure APC in a large contemporary series of well-characterized tumors have, to date, not been elucidated. Cases with APC defined as cancer present anterior to the urethra only were identified from 1761 consecutive radical prostatectomy specimens accessioned between January 2015 and August 2016. The clinicopathologic features of these cases were compared with those of pure posterior prostate cancer (PPC) and the features of anterior peripheral zone (APZ) cancers were compared with those of TZ cancers. In addition, the tumor series from 2015 to 2016 was compared with a cohort of 1054 patients accessioned before the utilization of multiparametric magnetic resonance imaging in the routine workup of patients with prostate cancer. In the 2015-2016 series, there were 188 (10.7%) patients with APC compared with 5.4% in the series from the pre-multiparametric magnetic resonance imaging era. No difference was observed between APC and PPC with regards to patient age or mean serum prostate-specific antigen at presentation. Mean tumor volume and positive surgical margin (PSM) rates were significantly higher in APC. In contrast, PPC was more commonly high grade with more frequent extraprostatic extension (EPE). None of the cases of APC had infiltration of the seminal vesicle or lymph node involvement, in contrast to PPC, with almost 14% of cases in each category. The 3- and 5-year biochemical recurrence-free survival was significantly higher in APC when compared with PPC, although this was not retained on multivariable analysis which included tumor location. On division of APCs according to anatomic zone of origin, 45% were APZ cancer and 37% TZ cancer. On comparison of APZ and TZ cancers, there were no significant differences in mean age and serum prostate-specific antigen at presentation as well as tumor volume, Gleason score, and PSM rate. High-grade malignancy (Gleason score >3 + 4=7) was seen in 26% of TZ cancers which compared with 44% of APZ cancers and 56% of PPC cancers. The rate of EPE was significantly higher in APZ when compared with TZ cancer ( P< 0.0005); however, the biochemical recurrence rate was not significantly different between the groups. The prevalence of APC in radical prostatectomy specimens has increased in recent times, in association with earlier detection at a stage amenable to curative surgical treatment. APC, when compared with PPC, is less commonly high grade with less frequent EPE, despite the APC group having larger tumors and a higher PSM rate at presentation. However, not all anterior cancers are indolent. Anterior cancers are more commonly seen in the APZ than the TZ and APZ cancers appear more locally aggressive than TZ cancers.

Selecting patients for magnetic resonance imaging cognitive versus ultrasound fusion biopsy of the prostate: A within-patient comparison

Objectives

To compare overall agreement between magnetic resonance imaging (MRI)-ultrasound (US) fusion biopsy (FB) and MRI cognitive fusion biopsy (CB) of the prostate and determine which factors affect agreement for prostate cancer (PCa) who underwent both modalities in a prospective within-patient protocol.

Patients and Methods

From August 2017 to January 2021, patients with at least one Prostate Imaging Reporting & Data System (PI-RADS) 3 or higher lesion on multiparametric MRI underwent transrectal FB and CB in a prospective within-patient protocol. CB was performed for each region of interest (ROI), followed by FB, followed by standard 12 core biopsy. Patients who were not on active surveillance were analysed. The primary endpoint was agreement for any PCa detection. McNemar's test and kappa statistic were used to analyse agreement. Chi-square test, Fisher's exact test and Wilcoxon rank sum test were used to analyse disagreement across clinical and MRI spatial variables. A multivariable generalized mixed-effect model was used to compare the interaction between select variables and fusion modality. Statistics were performed using SAS and R.

Results

Ninety patients and 98 lesions were included in the analysis. There was moderate agreement between FB and CB (k = 0.715). McNemar's test was insignificant (p = 0.285). Anterior location was the only variable associated with a significant variation in agreement, which was 70% for anterior lesions versus 89.7% for non-anterior lesions (p = 0.035). Discordance did not vary significantly across other variables. In a mixed-effect model, the interaction between anterior location and use of FB was insignificant (p = 0.411).

Conclusion

In a within-patient protocol of patients not on active surveillance, FB and CB performed similarly for PCa detection and with moderate agreement. Anterior location was associated with significantly higher disagreement, whereas other patient and lesion characteristics were not. Additional studies are needed to determine optimal biopsy technique for sampling anterior ROI.

Targeted Multiparametric Magnetic Resonance Imaging/Ultrasound Fusion Biopsy for Quantitative Gleason 4 Grading Prediction in Radical Prostatectomy Specimens: Implications for Active Surveillance Candidate Selection

BACKGROUND

Quantitative Gleason grading appears to be a reliable prognostic parameter and provides broader risk stratification then the traditional Gleason grading in patients with prostate cancer (PCa) treated with radical prostatectomy (RP).

OBJECTIVE

To determine if quantification of Gleason pattern (GP) 4 for targeted and systematic biopsy (TBx + SBx) cores together with further clinical variables can identify the lowest quantitative GP 4 fraction on RP.

DESIGN, SETTING, AND PARTICIPANTS

A total of 548 patients underwent TBx + SBx of the prostate and then RP, with pathology revealing Gleason score 3 + 4, 4 + 3, or 4 + 4 disease.

INTERVENTION

TBx + SBx of the prostate followed by RP.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

GP 4 fraction thresholds of ≤5%, ≤10%, ≤15%, ≤20%, and ≤25% were compared between the TBx + SBx and RP specimens. The sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and accuracy for predicting the GP 4 fraction in the RP specimen were determined. Logistic regression models were used to establish a probabilistic relationship between various combinations of clinical and biopsy variables and the GP 4 fraction in the RP specimen.

RESULTS AND LIMITATIONS

GP 4 fractions of ≤5%, ≤10%, ≤15%, ≤20%, and ≤25% was observed in 33%, 49%, 58%, 65%, and 70% of patients on TBx, and 18%, 41%, 53%, 63%, and 70% of patients on RP, respectively. The sensitivity, specificity, NPV, PPV, and accuracy were 75%, 67%, 91%, 39%, and 74% for a TBx GP 4 fraction of ≤5%, and 65%, 85%, 65%, 85%, and 79% for a TBx GP 4 fraction of ≤25%, respectively. A model combining quantified TBx + SBx GP 4 with clinical parameters demonstrated the highest diagnostic accuracy. Limitations include the retrospective study design.

CONCLUSIONS

Our results demonstrate that the combination of MRI-TBx + SBx and GP 4 quantification allowed precise detection of a low fraction of GP 4 when using RP specimens as the reference standard. Moreover, we found that clinical variables including Prostate Imaging-Reporting and Data System score without biopsy are limited in detection of low GP 4 fractions.

PATIENT SUMMARY

Combination of targeted biopsy alone as well as combined with systematic biopsy and quantitative Gleason grading of biopsy specimen showed high agreement with pathology findings after surgical removal of the prostate. This could help in identifying patients who are suitable for active surveillance.

Pan-segmental intraprostatic lesions involving mid-gland and apex of prostate (mid-apical lesions): assessing the true value of extreme apical biopsy cores

Objective

When considering increased morbidity of apical biopsies, the added diagnostic value of separate targeting of mid-gland and apical segment of the pan-segmental mid-apical mpMRI prostate cancer (PCa) suspicious lesions was assessed.

Materials and methods

A total of 420 patients with a single mpMRI PCa-suspicious PI-RADS ≥ 3 intraprostatic lesion extending from the mid-gland to the apical segment of the gland underwent transrectal MRI-targeted (TBx) and systematic prostate biopsy. Clinically significant PCa (CsPCa) was defined as Gleason Score (GS) ≥ 3 + 4. PCa detection rates of TBx cores were assessed according to targeted anatomical segments. Finally, the diagnostic values of two theoretical TBx protocols utilizing 1-core (A) vs. 2-cores (B) per anatomical segment were compared.

Results

TBx within the pan-segmental mid-apical lesions yielded 44% of csPCa. After stratification into mid- vs. apical segment of the lesion, csPCa was detected in 36% (mid-gland) and 32% (apex), respectively. Within the patients who had no csPCa detection by mid-gland sampling (64%, n = 270), extreme apical TBx yielded additional 8.1% of csPCa. Comparison of extreme apical TBx strategy B vs. overall PCa detection in our cohort revealed corresponding similar rates of 49 vs.50% and 31 vs.32%, respectively.

Conclusion

Separate analyses of both segments, mid-gland and apex, clearly revealed the diagnostic contribution of apical TBx. Our findings strongly suggest to perform extreme apical TBx even within pan-segmental lesions. Moreover, our results indicate that a higher number of cores sampled from the mid-gland segment might be avoided if complemented with a two-core extreme apical TBx.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00345-022-04006-2.

Evaluating the diagnostic role of in-bore magnetic resonance imaging guided prostate biopsy: a single-centre study

Background

To evaluate the role of in‐bore MRI‐guided biopsy (IB‐MRGB) in the diagnosis of clinically significant prostate cancer (csPCa).

Methods

In this tertiary single centre study, a total of 125 consecutive patients receiving IB‐MRGB over a three‐year period were evaluated, including 73 patients who had prior biopsies and 52 biopsy‐naïve patients. We assessed cancer detection rate of patients according to the degree of suspicion based on mpMRI findings. Histopathological data were reviewed by experienced uropathologists.

Results

The mpMRI was suspicious for PCa (PI‐RADS 4/5) in 77% (96/125) and equivocal (PI‐RADS 3) in 23% (29/125). The detection rate for csPCa was 54.2% (52/96) and 20.7% (6/29) for suspicious lesions (PI‐RADS 4/5) and equivocal lesions (PI‐RADS 3), respectively. In subgroup analysis, patients with previous negative biopsy, overall positive biopsy rate and csPCa detection rate were 48.3% (19/35) and 34.5% (13/35), respectively. In patients on AS, 36/44 (81.8%) and 21/44 (47.8%) had PCa and csPCa respectively. In biopsy‐naïve patients 34/52 (65.4%) and 27/52 (51.92%) had PCa and csPCa respectively. Of the patients on AS, 18/44 (41.6%) upgraded from ISUP 1 to ISUP 2 PCa, and 4/44 (9.1%) upgraded from ISUP 1 to ISUP 3 PCa on IB‐MRGB. A total of 14 Clavien‐Dindo≤2 complications occurred in 14 patients (11.2%) that were directly related to the biopsy. No Clavien‐Dindo≥3 complications occurred.

Conclusion

MRI‐targeted biopsy is suitable for assessment of csPCa. Given the favourable complications profile, its use may be considered in both the initial biopsy and re‐biopsy settings.

The Global Research of Artificial Intelligence on Prostate Cancer: A 22-Year Bibliometric Analysis

Background

With the rapid development of technology, artificial intelligence (AI) has been widely used in the diagnosis and prognosis prediction of a variety of diseases, including prostate cancer. Facts have proved that AI has broad prospects in the accurate diagnosis and treatment of prostate cancer.

Objective

This study mainly summarizes the research on the application of artificial intelligence in the field of prostate cancer through bibliometric analysis and explores possible future research hotspots.

Methods

The articles and reviews regarding application of AI in prostate cancer between 1999 and 2020 were selected from Web of Science Core Collection on August 23, 2021. Microsoft Excel 2019 and GraphPad Prism 8 were applied to analyze the targeted variables. VOSviewer (version 1.6.16), Citespace (version 5.8.R2), and a widely used online bibliometric platform were used to conduct co-authorship, co-citation, and co-occurrence analysis of countries, institutions, authors, references, and keywords in this field.

Results

A total of 2,749 articles were selected in this study. AI-related research on prostate cancer increased exponentially in recent years, of which the USA was the most productive country with 1,342 publications, and had close cooperation with many countries. The most productive institution and researcher were the Henry Ford Health System and Tewari. However, the cooperation among most institutions or researchers was not close even if the high research outputs. The result of keyword analysis could divide all studies into three clusters: “Diagnosis and Prediction AI-related study”, “Non-surgery AI-related study”, and “Surgery AI-related study”. Meanwhile, the current research hotspots were “deep learning” and “multiparametric MRI”.

Conclusions

Artificial intelligence has broad application prospects in prostate cancer, and a growing number of scholars are devoted to AI-related research on prostate cancer. Meanwhile, the cooperation among various countries and institutions needs to be strengthened in the future. It can be projected that noninvasive diagnosis and accurate minimally invasive treatment through deep learning technology will still be the research focus in the next few years.

Multiparametric magnetic resonance imaging of the prostate: Lights and shadows

Prostate cancer is the second most commonly diagnosed cancer in man. Since the first MRI was performed, enormous progress has been made in diagnosis, treatment, and follow up of PCa, mainly due to multiparametric prostatic MRI (mpMRI). Although mpMRI has become the best imaging tool for identifying PCa, some limitations still exist. Prostate imaging with mpMRI is, to date, the best way to locate suspicious lesions to trigger prostate biopsy, plan active surveillance, or definitive treatment. In case of relapse, mpMRI can help detect local disease and provide specific management. It is well known that there is a subset of patients in whom mpMRI fails to depict csPCa. These missed significant cancers demand great attention. Prostate mpMRI quality depends on several factors related to equipment (including equipment vendor, magnet field and gradient strength, coil set used, software and hardware levels, sequence parameter choices), patient (medications, body habitus, motion, metal implants, rectal gas), and most importantly the radiologic interpretation of images (learning curve effects, subjectivity of observations, interobserver variations, and reporting styles). Inter-reader variability represents a huge current limitation of this method. Therefore, mpMRI remains the best imaging tool available to detect PCa, guiding diagnosis, treatment, and follow up while inter-reader variability represents the best limitation. Radiomics can help identifying imaging biomarkers to help radiologist in detecting significant PCa, reducing examination times, and costs.

MRI-targeted prostate biopsy: the next step forward!

Aim

For decades, the gold standard technique for diagnosing prostate cancer was the 10 to 12 core systematic transrectal or transperineal biopsy, under ultrasound guidance. Over the past years, an increased rate of false negative results and detection of clinically insignificant prostate cancer has been noted, resulting into overdiagnosis and overtreatment. The purpose of the current study was to evaluate the changes in diagnosis and management of prostate cancer brought by MRI-targeted prostate biopsy.

Methods

A critical review of literature was carried out using the Medline database through a PubMed search, 37 studies meeting the inclusion criteria: prospective studies published in the past 8 years with at least 100 patients per study, which used multiparametric magnetic resonance imaging as guidance for targeted biopsies.

Results

In-Bore MRI targeted biopsy and Fusion targeted biopsy outperform standard systematic biopsy both in terms of overall and clinically significant prostate cancer detection, and ensure a lower detection rate of insignificant prostate cancer, with fewer cores needed. In-Bore MRI targeted biopsy performs better than Fusion biopsy especially in cases of apical lesions.

Conclusion

Targeted biopsy is an emerging and developing technique which offers the needed improvements in diagnosing clinically significant prostate cancer and lowers the incidence of insignificant ones, providing a more accurate selection of the patients for active surveillance and focal therapies.

Visualized Prostate Biopsy: An Intuitive Three-Dimensional User Interface for Systematic and Targeted Biopsy

Background: Prostate biopsy false negative percentages are 21% to 47% and 16% to 30% for systematic and fused biopsy, respectively. An intuitive three-dimensional (3D) observed user interface may help reduce these percentages by providing real-time guidance and feedback during transrectal or transperineal biopsy. Materials and Methods: We track the moving prostate (including template locations and regions of interest), the transrectal ultrasound (TRUS) probe, and the biopsy device to construct a 3D environment. Users observe, aim, sample, and receive feedback in real time. Using a simulator with simulated TRUS, 48 participants performed freehand systematic prostate biopsy with traditional TRUS guidance and afterward with visualized prostate biopsy (vPBx). Results: During simulated biopsy, vPBx reduced the false negative percentage for a 0.5-mL spherical apical lesion from 52% to 2% (p < 0.001). Conclusions: Preliminary results during simulated systematic biopsy warrant retrofitting the vPBx to actual TRUS equipment as a step toward clinical trials with patients.

Combined MRI-targeted Plus Systematic Confirmatory Biopsy Improves Risk Stratification for Patients Enrolling on Active Surveillance for Prostate Cancer

OBJECTIVE

To evaluate the efficacy of combined MRI-targeted plus systematic 12-core biopsy (Cbx) to aid in the selection of patients for active surveillance (AS).

METHODS

From July 2007 to January 2020, patients with Gleason Grade Group (GG) 1 or GG 2 prostate cancer were referred to our center for AS consideration. All patients underwent an MRI and confirmatory combined MRI-targeted plus systematic biopsy (Cbx), and AS outcomes based on Cbx results were compared. Cox regression was used to identify predictors of AS failure, defined as progression to ≥ GG3 disease on follow-up biopsies.

RESULTS

Of 579 patients referred for AS, 79.3% (459/579) and 20.7% (120/579) had an initial diagnosis of GG1 and GG2 disease, respectively. Overall, 43.2% of patients (250/579) were upgraded on confirmatory Cbx, with 19.2% (111/579) upgraded to ≥ GG3. For the 226 patients followed on AS, 32.7% (74/226) had benign, 45.6% (103/226) had GG1, and 21.7% (49/226) had GG2 results on confirmatory Cbx. In total, 28.8% (65/226) of patients eventually progressed to ≥ GG3, with a median time to AS failure of 89 months. The median time from confirmatory Cbx to AS failure for the negative, GG1, and GG2 groups were 97, 97, and 32 months, respectively (p < .001). On multivariable regression, only age (hazard ratio 1.06 [1.02-1.11], p < .005) and GG on confirmatory Cbx (hazard ratio 2.75 [1.78-4.26], p < .005) remained as positive predictors of AS failure.

CONCLUSION

The confirmatory combined MRI-targeted plus systematic biopsy provides useful information for the risk stratification of patients at the time of AS enrollment.

Detection of clinically significant cancer in the anterior prostate by transperineal biopsy

OBJECTIVE

To determine the incidence of clinically significant prostate cancer (csPCa) detected exclusively in the anterior prostate using transperineal prostate biopsy.

PATIENTS AND METHODS

Histopathology results of all patients who underwent transperineal prostate biopsy between February 2016 and March 2018 at a single institution were assessed for distribution of cancer within the prostate. Patients with cancer found exclusively in the anterior prostate were then compared to those with any cancer found in the posterior or lateral prostate with International Society of Urological Pathology Grade Group 2-5 cancers being considered csPCa.

RESULTS

A total of 508 patients were included. Overall, 12.0% of the cohort had csPCa detected only in anterior biopsies. When stratified by prostate-specific antigen (PSA) level, 6.6% of men with a PSA level of 4.1-10.0 ng/mL and 8.2% of men with a PSA level of >10.0 ng/mL had csPCa detected in the anterior prostate alone.

CONCLUSION

Transperineal biopsy has the ability to diagnose anteriorly located csPCa that would potentially have been missed by the transrectal approach.

Combined systematic versus stand-alone multiparametric MRI-guided targeted fusion biopsy: nomogram prediction of non-organ-confined prostate cancer

OBJECTIVE

Based on unfavorable oncological and functional outcomes of non-organ-confined (NOC) prostate cancer (PCa), defined as ≥ pT3, pN1 or both, we aimed to develop a NOC prediction tool based on multiparametric MRI-guided targeted fusion biopsy (TBx).

MATERIALS AND METHODS

Analyses were restricted to 594 patients with simultaneous PCa detection at systematic biopsy (SBx), TBx and subsequent radical prostatectomy (RP) at our institution. Development (n = 396; cohort 1) and validation cohorts (n = 198; cohort 2) were used to develop and validate the NOC nomogram. A head-to-head comparison was performed between stand-alone TBx model and combined TBx/SBx model. Second validation was performed in patients with positive TBx, but negative SBx (n = 193; cohort 3).

RESULTS

The most parsimonious TBx model included three independent predictors of NOC: pretreatment PSA (OR 1.05 95% CI: 1.01-1.08), highest TBx-detected Gleason pattern (3 + 3 [REF] vs. ≥ 4 + 5; OR 9.3 95% CI 3.8-22) and presence of TBx-detected perineural invasion (OR 2.2 95% CI: 1.3-3.6). The combined TBx/SBx model had the same predictors. For the stand-alone TBx and combined TBx/SBx model, external validation yielded accuracy of 76.5% (95% CI: 69.3-83.1) and 76.6% (95% CI: 69.4-83.6) within cohort 2. The external validation of the stand-alone TBx model yielded 72.4% (95% CI: 65.0-79.6) accuracy within cohort 3.

CONCLUSION

Our stand-alone TBx-based nomogram can identify PCa patients at the risk of NOC, using three simple variables, with the similar accuracy as the TBx/SBx-based model. It is non-inferior to combined TBx/SBx-based model and performs with sufficient accuracy in specific patients with positive TBx, but negative SBx.

Additive Value of Transrectal Systematic Ventral Biopsies in Combination with Magnet Resonance Imaging/Ultrasound Fusion-Guided Biopsy in Patients with 3 or More Negative Prostate Biopsies

INTRODUCTION

Patients with consistent suspicion for prostate cancer (PCa) and multiple negative prebiopsies prior to multiparametric magnetic resonance imaging (mpMRI) are still frequently evaluated for an image-guided biopsy and are reported with heterogeneous detection rates. The inclusion of a systematic biopsy (SB) is also still recommended with predominant sampling within the posterior/peripheral zone of the prostate. The aim of this study was (I) to evaluate PCa detection rates using a modified 10 core SB template including anterior biopsies in combination with mpMRI/ultrasound fusion-guided targeted biopsy (TB) in patients with 3 or more negative prebiopsies and (II) to compare mpMRI index lesion localization with histologically confirmed locali-zation from associated prostatectomy samples.

METHODS

Overall 1,337 consecutive patients underwent sensor-based registration TB of the prostate and a subsequent 10-core SB between January 2012 and December 2015 at our institution. For this study, 101 patients with ≥3 negative prebiopsies and prostate imaging - reporting data system lesions ≥3 were pooled prospectively and underwent TB and a modified SB including 2 ventral (anterior) biopsies. Detection rates were estimated for the modified SB, TB, and its combination. A subgroup analysis of 35 patients undergoing prostatectomy was performed by a head-to-head comparison of mpMRI index lesion and histologically confirmed PCa index lesion localization.

RESULTS

The overall detection rate for PCa was 54.5%. The combination of TB and SB detected 14 (25.4%) more cases missed by TB alone (p < 0.001) and 7 (12.7%) more cases missed by SB alone (p = 0.016), respectively. A postoperative Gleason upgrade was seen in 12/35 (34.3%) cases within the TB group and in 14/35 (40.0%) in the SB group, respectively. The subgroup analysis showed a predominant location of PCa index lesions anteriorly at the level of the midgland. The MRI detection rate of the anteriorly located index lesions was 70.4% (15/21 cases) with a clinically significant Gleason score (≥3 + 4 = 7a [International Society of Urological Pathology grade 2]) in 80.9%. Interestingly a modified SB template detected 90.5% (19/21) of the anteriorly located index lesions.

CONCLUSION

Our data suggest that in patients with multiple prebiopsies PCa seems to be predominantly located anteriorly. We suggest the general integration of anterior biopsies despite TB in repeat biopsy patients.

Rectal Swabs for Detecting Multidrug Resistant Bacteria Prior to Transrectal Prostate Fusion Biopsy: A Prospective Evaluation of Risk Factor Screening and Microbiologic Findings

OBJECTIVE

To assess the prevalence of fluoroquinolone resistant (QR) bacteria, multidrug resistant (MDR) bacteria and Enterococcus faecalis (E. faecalis) in rectal swabs of patients undergoing transrectal prostate biopsy and for evaluating if risk factor assessment is reliable for prediction of QR bacteria, MDR bacteria, or E. faecalis.

PATIENTS AND METHODS

Two hundred consecutive patients received a rectal swab examination prior to transrectal magnetic resonance imaging-guided fusion biopsy, for evaluating the prevalence of QR bacteria, MDR bacteria, and E. faecalis. The results of a standardized risk factor questionnaire, assessing known prognosticators for higher prevalence of resistant bacteria in rectal flora were correlated with the occurrence of QR bacteria, MDR bacteria, and E. faecalis in rectal swabs.

RESULTS

QR E. coli was detected in 12 patients (6%). Regarding MDR bacteria, extended spectrum β- lactamase- producing E. coli occurred in 8 patients (4%). E. faecalis was found in 15 patients (7.5%). A total of 193 patients completed the risk factor questionnaire. Of those, 107 (53.2%) patients harbored no risk factors, while 86 (42.8%) had at least 1 risk factor, of which the most common was repeat biopsy. No association was found between any risk factor and occurrence of QR bacteria, MDR bacteria, or E. faecalis (P >.05).

CONCLUSION

The prevalence of resistant germs in our cohort was lower compared to other series. Moreover, the rate of QR bacteria, MDR bacteria, or E. faecalis in rectal swabs was not reliably associated with risk factor assessment.