Transperineal Template Guided Prostate Biopsy Selects Candidates for Active Surveillance--How Many Cores are Enough?

How many cores are enough? Optimizing the transperineal prostate biopsy template

INTRODUCTION AND OBJECTIVE

Most urologists use a 10-12 core template during transrectal ultrasound guided prostate biopsy (TRUS-B). A similar consensus template does not exist for transperineal prostate biopsy (TP-B) including the optimal number and location of biopsy cores. We examined our institutional cohort to develop an optimal systematic template for TP-B.

METHODS

We prospectively monitored our first 200 consecutive free-hand TP-B. These included men who were biopsy naïve (n = 117), had elevated PSA with prior negative biopsy (n = 18), and men on active surveillance (n = 65). All men underwent a 20 core TP-B with each core placed in a separate specimen container. This allowed the 20-core TP-B to be easily broken down as though fewer cores had been taken in each patient. Ten, 12, and 16 core templates were designed a priori and compared within each patient to the 20 core template. The highest Grade Group (GG) at pathologic analysis was assigned to each biopsy. Primary outcome was detection of clinically significant prostate cancer, defined as ≥GG2. Secondary outcome was detection of GG1 prostate cancer. We performed sub-group analyses of biopsy naïve men and biopsy naïve men stratified by PSA density (<0.15 vs. ≥0.15 ng/mL/cc). An historic institutional cohort of 10-12 core TRUS-B (n = 170) was used to compare prostate cancer detection between techniques. P value of ≤0.05 was considered statistically significant.

RESULTS

Clinically significant cancers were detected in 98 men (49%) using a 20 core TP-B technique. Had we sampled fewer cores we would have identified clinically significant cancers in 93 (47%, 16 core), 91 (46%, 12 core), and 82 (41%, 10 core) men. More clinically significant cancers were detected by the 20 core template compared to the 10 core template for both the whole cohort (49% vs. 41%, P = 0.02) and the biopsy naïve subset (48% vs. 40%, P = 0.05). Additional cores did not result in an increased detection of GG1 cancers (20-core: 35% vs. 10-core: 44%, P = 0.09). Less than one quarter of biopsy naïve men with a PSA density <0.15 were found to have clinically significant cancers. More clinically significant cancers were detected in the 12-core TP-B cohort compared to the 12-core TRUS-B series (46% vs. 38%, P < 0.001).

CONCLUSIONS

A 20 core TP-B systematic biopsy template detected a greater number of clinically significant prostate cancers compared to a 10 core TP template. Cancer detection was similar for 12, 16, and 20 core templates. Higher core numbers did not result in greater detection of GG1 tumors reflecting increased detection of concomitant ≥GG2 with greater sampling. We propose a minimum 12 core systematic biopsy template for men undergoing TP-B.

Gleason grade accuracy of transperineal and transrectal prostate biopsies in MRI-naïve patients

PURPOSE

Accurate assessment of Gleason grade is essential to guiding prostate cancer management. Not all healthcare systems have universal access to prostate MRI. We investigated whether transperineal (TP) prostate biopsies provide more accurate Gleason grading than transrectal (TR) biopsies in MRI-naïve patients.

METHODS

Consecutive patients undergoing TP and TR systematic prostate needle biopsies from 2011 to 2018 were analysed. Patients who underwent radical prostatectomy (RP) within 180 days of biopsies were included. Patients undergoing MRI prior to biopsies were excluded. Pathological concordance, incidence of Gleason upgrading, and correlation coefficients among biopsies and RP Gleason grade were compared. A sub-analysis for concordance in anterior prostate tumours was conducted.

RESULTS

262 patients were included (112 TP; 150 TR), the median age was 63 years, and median time from biopsy to RP was 68 days. Concordance with RP histology for TP was 65% compared to 49% for TR (p = 0.011). Biopsy technique predicted RP concordance independent of the number of cores. Gleason upgrading occurred following 24% of TP versus 33% of TR biopsies. In anterior and apical tumours, upgrading occurred in 19% of TP biopsies and 38% of TR biopsies (p = 0.027).

CONCLUSION

This study suggests TP approach to prostate biopsies result in improved histological grade accuracy in men whom MRI is not available, even after controlling for number of cores. TP approach also resulted in less upgrading for lesions in the anterior and apical prostate compared to TR.

The clinical utility of transperineal template-guided saturation prostate biopsy for risk stratification after transrectal ultrasound-guided biopsy

Purpose

To investigate the clinical utility of transperineal template-guided saturation prostate biopsy (TPB) for risk stratification after transrectal ultrasound (TRUS)-guided biopsy.

Materials and Methods

We retrospectively reviewed 155 patients who underwent TPB after previously negative results on TRUS-guided biopsy (n=58) or who were candidates for active surveillance (n=97) fulfilling the PRIAS criteria between May 2017 and November 2018. The patients' clinicopathologic data were reviewed, and the detection of clinically significant cancer (CSC) and upgrading of Gleason grade were identified.

Results

The patients' median age and pre-TPB prostate-specific antigen (PSA) value were 65.0 years and 5.74 ng/mL, respectively. A median of 36 biopsy cores was obtained in each patient, with a median TPB core density of 0.88 cores/cm³. Of the 58 males with a previous negative result on TRUS-guided biopsy, prostate cancer (PCa) was detected in 17 males (29.3%), including 8 with CSC. Of the 97 patient candidates for active surveillance, upgrading of the Gleason grade was identified in 31 males (32.0%), 20 with a Gleason grade of 7 (3+4), 6 with a Gleason grade of 7 (4+3), and 5 with a Gleason grade of 8 (4+4). The overall complication rate was 14.8% (23/155), and there were no Clavien–Dindo grade 3 to 5 complications.

Conclusions

TPB helps to stratify the risk of PCa that was previously missed or underdiagnosed by TRUS-guided biopsy. TPB might be used as a diagnostic tool to determine risk classification and to help counsel patients with regard to treatment decisions.

Prostate MRI, with or without MRI-targeted biopsy, and systematic biopsy for detecting prostate cancer

BACKGROUND

Multiparametric magnetic resonance imaging (MRI), with or without MRI-targeted biopsy, is an alternative test to systematic transrectal ultrasonography-guided biopsy in men suspected of having prostate cancer. At present, evidence on which test to use is insufficient to inform detailed evidence-based decision-making.

OBJECTIVES

To determine the diagnostic accuracy of the index tests MRI only, MRI-targeted biopsy, the MRI pathway (MRI with or without MRI-targeted biopsy) and systematic biopsy as compared to template-guided biopsy as the reference standard in detecting clinically significant prostate cancer as the target condition, defined as International Society of Urological Pathology (ISUP) grade 2 or higher. Secondary target conditions were the detection of grade 1 and grade 3 or higher-grade prostate cancer, and a potential change in the number of biopsy procedures.

SEARCH METHODS

We performed a comprehensive systematic literature search up to 31 July 2018. We searched CENTRAL, MEDLINE, Embase, eight other databases and one trials register.

SELECTION CRITERIA

We considered for inclusion any cross-sectional study if it investigated one or more index tests verified by the reference standard, or if it investigated the agreement between the MRI pathway and systematic biopsy, both performed in the same men. We included only studies on men who were biopsy naïve or who previously had a negative biopsy (or a mix of both). Studies involving MRI had to report on both MRI-positive and MRI-negative men. All studies had to report on the primary target condition.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and assessed the risk of bias using the QUADAS-2 tool. To estimate test accuracy, we calculated sensitivity and specificity using the bivariate model. To estimate agreement between the MRI pathway and systematic biopsy, we synthesised detection ratios by performing random-effects meta-analyses. To estimate the proportions of participants with prostate cancer detected by only one of the index tests, we used random-effects multinomial or binary logistic regression models. For the main comparisions, we assessed the certainty of evidence using GRADE.

MAIN RESULTS

The test accuracy analyses included 18 studies overall.MRI compared to template-guided biopsy: Based on a pooled sensitivity of 0.91 (95% confidence interval (CI): 0.83 to 0.95; 12 studies; low certainty of evidence) and a pooled specificity of 0.37 (95% CI: 0.29 to 0.46; 12 studies; low certainty of evidence) using a baseline prevalence of 30%, MRI may result in 273 (95% CI: 249 to 285) true positives, 441 false positives (95% CI: 378 to 497), 259 true negatives (95% CI: 203 to 322) and 27 (95% CI: 15 to 51) false negatives per 1000 men. We downgraded the certainty of evidence for study limitations and inconsistency.MRI-targeted biopsy compared to template-guided biopsy: Based on a pooled sensitivity of 0.80 (95% CI: 0.69 to 0.87; 8 studies; low certainty of evidence) and a pooled specificity of 0.94 (95% CI: 0.90 to 0.97; 8 studies; low certainty of evidence) using a baseline prevalence of 30%, MRI-targeted biopsy may result in 240 (95% CI: 207 to 261) true positives, 42 (95% CI: 21 to 70) false positives, 658 (95% CI: 630 to 679) true negatives and 60 (95% CI: 39 to 93) false negatives per 1000 men. We downgraded the certainty of evidence for study limitations and inconsistency.The MRI pathway compared to template-guided biopsy: Based on a pooled sensitivity of 0.72 (95% CI: 0.60 to 0.82; 8 studies; low certainty of evidence) and a pooled specificity of 0.96 (95% CI: 0.94 to 0.98; 8 studies; low certainty of evidence) using a baseline prevalence of 30%, the MRI pathway may result in 216 (95% CI: 180 to 246) true positives, 28 (95% CI: 14 to 42) false positives, 672 (95% CI: 658 to 686) true negatives and 84 (95% CI: 54 to 120) false negatives per 1000 men. We downgraded the certainty of evidence for study limitations, inconsistency and imprecision.Systemic biopsy compared to template-guided biopsy: Based on a pooled sensitivity of 0.63 (95% CI: 0.19 to 0.93; 4 studies; low certainty of evidence) and a pooled specificity of 1.00 (95% CI: 0.91 to 1.00; 4 studies; low certainty of evidence) using a baseline prevalence of 30%, systematic biopsy may result in 189 (95% CI: 57 to 279) true positives, 0 (95% CI: 0 to 63) false positives, 700 (95% CI: 637 to 700) true negatives and 111 (95% CI: 21 to 243) false negatives per 1000 men. We downgraded the certainty of evidence for study limitations and inconsistency.Agreement analyses: In a mixed population of both biopsy-naïve and prior-negative biopsy men comparing the MRI pathway to systematic biopsy, we found a pooled detection ratio of 1.12 (95% CI: 1.02 to 1.23; 25 studies). We found pooled detection ratios of 1.44 (95% CI 1.19 to 1.75; 10 studies) in prior-negative biopsy men and 1.05 (95% CI: 0.95 to 1.16; 20 studies) in biopsy-naïve men.

AUTHORS' CONCLUSIONS

Among the diagnostic strategies considered, the MRI pathway has the most favourable diagnostic accuracy in clinically significant prostate cancer detection. Compared to systematic biopsy, it increases the number of significant cancer detected while reducing the number of insignificant cancer diagnosed. The certainty in our findings was reduced by study limitations, specifically issues surrounding selection bias, as well as inconsistency. Based on these findings, further improvement of prostate cancer diagnostic pathways should be pursued.

Standardized Magnetic Resonance Imaging Reporting Using the Prostate Cancer Radiological Estimation of Change in Sequential Evaluation Criteria and Magnetic Resonance Imaging/Transrectal Ultrasound Fusion with Transperineal Saturation Biopsy to Select Men on Active Surveillance

BACKGROUND

Contemporary selection criteria for men with prostate cancer (PC) suitable for active surveillance (AS) are unsatisfactory, leading to high disqualification rates based on tumor misclassification. Conventional biopsy protocols are based on standard 12-core transrectal ultrasound (TRUS) biopsy.

OBJECTIVE

To assess the value of magnetic resonance imaging (MRI)/TRUS fusion biopsy over 4-yr follow-up in men on AS for low-risk PC.

DESIGN, SETTING, AND PARTICIPANTS

Between 2010 and 2018, a total of 273 men were included. Of them, 157 men with initial 12-core TRUS biopsy and 116 with initial MRI/TRUS fusion biopsy were followed by systematic and targeted transperineal MRI/TRUS fusion biopsies based on Prostate Cancer Research International Active Surveillance criteria. MRI from follow-up MRI/TRUS fusion biopsy was assessed using the Prostate Cancer Radiological Estimation of Change in Sequential Evaluation (PRECISE) scoring system.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

AS-disqualification rates for patients on AS initially diagnosed by either 12-core TRUS biopsy or by MRI/TRUS fusion biopsy were compared using Kaplan-Meier estimates, log-rank tests, and regression analyses. We also analyzed the influence of negative primary MRI and PRECISE scoring to predict AS disqualification using Kaplan-Meier estimates, log-rank tests, and receiver operating characteristic (ROC) curve analysis.

RESULTS AND LIMITATIONS

Of men diagnosed by 12-core TRUS biopsy, 59% were disqualified from AS based on the results of subsequent MRI/TRUS fusion biopsy. In the initial MRI fusion biopsy cohort, upgrading occurred significantly less frequently (19%, p<0.001). ROC curve analyses demonstrated good discrimination for the PRECISE score with an area under the curve of 0.83. No men with a PRECISE score of 1 or 2 (demonstrating absence or downgrading of lesions in follow-up MRI) were disqualified from AS. In our cohort, a negative baseline MRI scan was not a predictor of nondisqualification from AS. Limitations include transperineal approach and extended systematic biopsies used with MRI/TRUS fusion biopsy, which may not be representative of other centers.

CONCLUSIONS

MRI/TRUS fusion biopsies allow a reliable risk classification for patients who are candidates for AS. The application of the PRECISE scoring system demonstrated good discrimination.

PATIENT SUMMARY

In this study, we investigated the value of multiparametric magnetic resonance imaging (MRI) and MRI/transrectal ultrasound (TRUS) fusion biopsies for the assessment of active surveillance (AS) reliability using the Prostate Cancer Radiological Estimation of Change in Sequential Evaluation criteria. Standard TRUS biopsies lead to significant underestimation of prostate cancer. In contrast, MRI/TRUS fusion biopsies allowed for a more reliable risk classification. For appropriate inclusion into AS, men should receive either an initial or a confirmatory MRI/TRUS fusion biopsy.

Histopathologic False-positive Diagnoses of Prostate Cancer in the Age of Immunohistochemistry

There are few studies into the rate and causes of histopathologic false-positive diagnosis of prostate cancer. Only 2 of these, including a previous one from our group, incorporate survival data. In addition, in none of the previous studies had immunohistochemistry (IHC) been originally requested on any of the misdiagnosed cases. Diagnostic biopsies (n=1080) and transurethral resection of prostate specimens (n=314) from 1394 men with clinically localized prostate cancer diagnosed in the United Kingdom but treated conservatively between 1990 and 2003 were reviewed by a panel of 3 genitourinary pathologists. Thirty-five cases were excluded for being potentially incomplete. Of the remaining 1359, 30 (2.2%) were reassigned to a nonmalignant category (26 benign and 4 suspicious for malignancy). IHC had been originally performed on 7 of these. The reasons for the errors were recorded on each case: adenosis (19), partial atrophy (3), prostatic intraepithelial neoplasia (2), seminal vesicle epithelium (1), and hyperplasia (1). Follow-up of these men revealed only one prostate cancer-related death, possibly due to unsampled tumor. In conclusion, a relatively small number of prostate cancer mimics were responsible for a large proportion of the false-positive prostate cancer diagnoses and the use of IHC did not prevent the overcall of benign entities as cancer in approximately a quarter of these cases. Targeting these mimics at educational events and raising awareness of the pitfalls in the interpretation of IHC in prostate cancer diagnosis, emphasizing that glands within a suspicious focus should be treated as a whole rather than individually, may be beneficial in lowering the rate of false-positive diagnosis.

Utility of early transperineal template-guided prostate biopsy for risk stratification in men undergoing active surveillance for prostate cancer

OBJECTIVE

To assess the accuracy and utility of routine multiparametric magnetic resonance imaging (mpMRI) and transperineal template-guided prostate biopsy (TPB) after enrolment in active surveillance (AS).

PATIENTS AND METHODS

From April 2012 to December 2016 consecutive men from our single institution, diagnosed with low- or intermediate-risk prostate cancer on transrectal ultrasonography-guided biopsy, were offered further staging with early mpMRI and TPB within 12 months of diagnosis. Data were collected prospectively. Eligibility criteria comprised: age ≤77 years; Gleason score ≤3 + 4; clinical stage T1-T2; PSA ≤15 ng/mL; and <50% positive biopsy cores.

RESULTS

A total of 208 men were enrolled, including 196 with Gleason score 3 + 3 and 12 with Gleason score 3 + 4 disease. The median (range) number of TPB cores was 50 (17-161), with a mean TPB core density of 1.2 cores/cm³ prostate volume. A total of 83 men (39.9%) underwent histopathological upgrading after TPB, including 76 men (38.8%) with Gleason score 3 + 3 disease and seven men (58.3%) with Gleason score 3 + 4 disease. Of these, 26 (31.3%) were found to harbour primary pattern Gleason grade ≥4 disease. In all, 24 (28.9%) upgraded cases had Prostate Imaging Reporting and Data System (PI-RADS) score 1 or 2 lesions on mpMRI, including five men with Gleason score ≥4 + 3 disease. Of these, 14 (58.3%) had a prostate-specific antigen (PSA) density of ≥0.15, including four out of the five men with Gleason ≥4 + 3 disease. Overall there was a change in prostate cancer management in 77 men (37.0%) after TPB.

CONCLUSIONS

Early TPB during AS is associated with significant upgrading and a change in treatment plan in over a third of men. If TPB was omitted in men with a PI-RADS score <3 and a PSA density <0.15, 12% of those harbouring more significant disease would have been misclassified.

Magnetic Resonance and Ultrasound Image Fusion Supported Transperineal Prostate Biopsy Using the Ginsburg Protocol: Technique, Learning Points, and Biopsy Results

BACKGROUND

Prostate biopsy supported by transperineal image fusion has recently been developed as a new method to the improve accuracy of prostate cancer detection.

OBJECTIVE

To describe the Ginsburg protocol for transperineal prostate biopsy supported by multiparametric magnetic resonance imaging (mpMRI) and transrectal ultrasound (TRUS) image fusion, provide learning points for its application, and report biopsy results. The article is supplemented by a Surgery in Motion video.

DESIGN, SETTING, AND PARTICIPANTS

This single-centre retrospective outcome study included 534 patients from March 2012 to October 2015. A total of 107 had no previous prostate biopsy, 295 had benign TRUS-guided biopsies, and 159 were on active surveillance for low-risk cancer.

SURGICAL PROCEDURE

A Likert scale reported mpMRI for suspicion of cancer from 1 (no suspicion) to 5 (cancer highly likely). Transperineal biopsies were obtained under general anaesthesia using BiopSee fusion software (Medcom, Darmstadt, Germany). All patients had systematic biopsies, two cores from each of 12 anatomic sectors. Likert 3-5 lesions were targeted with a further two cores per lesion.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Any cancer and Gleason score 7-10 cancer on biopsy were noted. Descriptive statistics and positive predictive values (PPVs) and negative predictive values (NPVs) were calculated.

RESULTS AND LIMITATIONS

The detection rate of Gleason score 7-10 cancer was similar across clinical groups. Likert scale 3-5 MRI lesions were reported in 378 (71%) of the patients. Cancer was detected in 249 (66%) and Gleason score 7-10 cancer was noted in 157 (42%) of these patients. PPV for detecting 7-10 cancer was 0.15 for Likert score 3, 0.43 for score 4, and 0.63 for score 5. NPV of Likert 1-2 findings was 0.87 for Gleason score 7-10 and 0.97 for Gleason score ≥4+3=7 cancer. Limitations include lack of data on complications.

CONCLUSIONS

Transperineal prostate biopsy supported by MRI/TRUS image fusion using the Ginsburg protocol yielded high detection rates of Gleason score 7-10 cancer. Because the NPV for excluding Gleason score 7-10 cancer was very high, prostate biopsies may not be needed for all men with elevated prostate-specific antigen values and nonsuspicious mpMRI.

PATIENT SUMMARY

We present our technique to sample (biopsy) the prostate by the transperineal route (the area between the scrotum and the anus) to detect prostate cancer using a fusion of magnetic resonance and ultrasound images to guide the sampling.

Can MRI/TRUS fusion targeted biopsy replace saturation prostate biopsy in the re-evaluation of men in active surveillance?

PURPOSE

The detection rate for significant prostate cancer of mMRI/TRUS fusion targeted biopsy versus saturation prostate biopsy was prospectively evaluated in men enrolled in active surveillance (AS) protocol.

METHODS

From May 2013 to January 2015, 40 men aged 66 years (median) with very low-risk PCa were enrolled in an AS protocol, and eligible criteria were: life expectancy greater than 10 years, cT1C, PSA below 10 ng/ml, PSA density <0.20, ≤2 unilateral positive biopsy cores, Gleason score (GS) equal to 6, greatest percentage of cancer (GPC) in a core ≤50 %. All patients underwent 3.0-Tesla pelvic mpMRI before confirmatory transperineal saturation biopsy (SPBx; median 30 cores) combined with mpMRI/TRUS fusion targeted biopsy (median 4 cores) of suspicious lesions (PI-RADS 4-5).

RESULTS

Ten out of 40 (25 %) patients were reclassified by SPBx based on upgraded GS ≥ 7; mpMRI found all the lesions predictive of significant PCa showing a false-positive rate equal to 5 %; on the contrary, mpMRI/TRUS targeted biopsy missed 3/10 (30 %) significant PCa characterised by the presence of a single positive core of GS ≥ 7 and GPC ≤ 5 %, suggesting that reduced number of targeted biopsies could miss small but significant PCa. Diagnostic accuracy, sensitivity, specificity, and positive and negative predictive value of mpMRI in diagnosing significant PCa were 95.2, 100, 93.8, 83.4, 100 %, respectively.

CONCLUSIONS

Although mpMRI provided high diagnostic accuracy (about 95 %) in diagnosing clinically significant PCa, mpMRI/TRUS fusion targeted biopsy cannot replace SPBx at confirmatory biopsy of men enrolled in AS protocols.