Transrectal ultrasound-guided biopsy of the prostate gland: value of 12 versus 6 cores

Transperineal ultrasound-guided prostate biopsy: what the radiologist needs to know

Transperineal ultrasound-guided (TP) prostate biopsy has been shown to significantly decrease the risk of post-procedural sepsis when compared to transrectal ultrasound-guided (TRUS) prostate biopsy. With guidance from the European Urology Association favouring adoption of a TP biopsy route, it is clear that, despite being a more technically challenging procedure, TP biopsy in an outpatient setting will replace TRUS biopsy. This paper gives the reader a succinct summary of outpatient transperineal prostate biopsy under local anaesthetic utilising a free-hand ultrasound technique. Patient preparation and consent process is outlined. A comprehensive pictorial review of the procedure, pitfalls and common post-procedural outcomes is presented. This paper provides a framework and guide for those wishing to adopt the transperineal approach under local anaesthetic.

Change from Transrectal to Transperineal Ultrasound-Guided Prostate Biopsy under local anaesthetic eliminates sepsis as a complication

Transrectal ultrasound-guided (TRUS) biopsy of the prostate is associated with an increased risk of post-procedural sepsis with associated morbidity, mortality, readmission to hospital and increased healthcare costs. In our institution, active surveillance of post-procedure infection complications is performed by the Clinical Nurse Specialists for prostate cancer under the guidance of the Infection Prevention and Control Team. To protect hospital services for acute medical admissions related to the COVID-19 pandemic, TRUS biopsy services were reduced nationally, with exceptions only for those patients at high risk of prostate cancer. In our institution, this change prompted a complete move to transperineal (TP) prostate biopsy performed in outpatients under local anaesthetic. TP biopsies eliminated the risk of post-procedural sepsis and, consequently, sepsis-related admission while maintaining a service for prostate cancer diagnosis during the COVID-19 pandemic.

Complications of transrectal prostate biopsy in our context. International multicenter study of 3350 patients

INTRODUCTION

Prostate cancer is the most common visceral neoplasm in men and the second one in the United States with the highest mortality behind lung cancer and ahead of colorectal cancer. While prostate cancer mortality rates have been reduced in the United States, Austria, United Kingdom and France, 5-year survival rates have been incremented in Sweden, probably due to a higher diagnostic activity and non-lethal tumor detection. TRPB usually has low rates of serious complications, with a not negligible number of minor complications. Mortality directly associated with this procedure is low and usually related to septic shock. The main complications derived from prostate biopsy can be infectious (mild or severe) and non-infectious (hematuria consistent with hemorrhage, urethral bleeding, rectal bleeding or hemospermia, acute urinary retention, pain or vasovagal reactions).

MATERIAL AND METHOD

The objective of the study is to compare three usual TRPB protocols and their relationship with the incidence of complications. Retrospective multicenter observational study conducted in three countries (Spain, Italy and Portugal). We have reviewed the medical records of 3350 men who underwent TRPB to evaluate the existence of prostate cancer, with a minimum evolutionary control of 6months.

RESULTS

The mean age was 65,50years, median 66, range 43-79. The subgroup analysis showed that younger patients had higher rates of acute urine retention (AUR) (P=.0000001). Likewise, our results revealed that younger patients presented more procedural pain (P=.0000001) than older patients. Regarding PSA, the mean value was 10.44, SD 7.73, median 8.15, range 0.98-68.09. A higher body mass index (BMI) was not associated with further infection (P=.000004). When performing the multivariate analysis, it was found that the significant variables in the general group were: age (P=.0013), PSA (P=.0402), local infiltration anesthesia (P=.0001) and prophylaxis with metronidazole +tobramycin +amoxicillin/clavulanic acid +gentamicin (P=.0001), presenting a normal distribution with high confidence interval (95%) and significant correlation. Prophylaxis is the most significant variable for no complications and pain (P=.0001), age (P=.0013) and prophylaxis (P=.0001) are for bleeding, age (P=.0013), prophylaxis and PSA (P=.0001) are for infection, and finally, age (P=.0013), anesthesia with local infiltration and prophylaxis (P=.0001) and PSA (P=.0402) are for AUR.

CONCLUSIONS

Sedation has fewer side effects and complications related to the transrectal prostate biopsy procedure with respect to transrectal local anesthesia. The choice of the antibiotic prophylaxis scheme is decisive in the onset of complications arising from the performance of a transrectal prostate biopsy.

Transperineal ultrasound-guided 12-core prostate biopsy: an extended approach to diagnose transition zone prostate tumors

Objective

Transperineal ultrasound-guided (TPUS) 12-core prostate biopsy was evaluated as an initial strategy for the diagnosis of prostate cancer, The distribution of prostate cancer lesions was assessed with zone-specific biopsy.

Methods

From January 2010 to December 2012, 287 patients underwent TPUS-guided 12-core prostate biopsy. Multiple cores were obtained from both the peripheral zone (PZ) and the transition zone (TZ) of the prostate. Participants' clinical data and the diagnostic yield of the cores were recorded and prospectively analyzed as a cross-sectional study.

Results

The diagnostic yield of the 12-core prostate biopsy was significantly higher compared to the 6-core scheme (42.16 vs. 21.6%). The diagnostic yield of the 10-core prostate biopsy was significantly higher compared to the 6-core scheme (37.6 vs. 21.6%). The 12-core scheme improved the diagnostic yield in prostates >50 ml (12-core scheme: 28.1% vs. 10-core scheme: 20.4%; p = 0.034).

Conclusions

The 12-core biopsy scheme is a safe and effective approach for the diagnosis of prostate cancer. TZ biopsies in patients with larger prostates should be included in the initial biopsy strategy.

Systematic review of complications of prostate biopsy

CONTEXT

Prostate biopsy is commonly performed for cancer detection and management. The benefits and risks of prostate biopsy are germane to ongoing debates about prostate cancer screening and treatment.

OBJECTIVE

To perform a systematic review of complications from prostate biopsy.

EVIDENCE ACQUISITION

A literature search was performed using PubMed and Embase, supplemented with additional references. Articles were reviewed for data on the following complications: hematuria, rectal bleeding, hematospermia, infection, pain, lower urinary tract symptoms (LUTS), urinary retention, erectile dysfunction, and mortality.

EVIDENCE SYNTHESIS

After biopsy, hematuria and hematospermia are common but typically mild and self-limiting. Severe rectal bleeding is uncommon. Despite antimicrobial prophylaxis, infectious complications are increasing over time and are the most common reason for hospitalization after biopsy. Pain may occur at several stages of prostate biopsy and can be mitigated by anesthetic agents and anxiety-reduction techniques. Up to 25% of men have transient LUTS after biopsy, and <2% have frank urinary retention, with slightly higher rates reported after transperineal template biopsy. Biopsy-related mortality is rare.

CONCLUSIONS

Preparation for biopsy should include antimicrobial prophylaxis and pain management. Prostate biopsy is frequently associated with minor bleeding and urinary symptoms that usually do not require intervention. Infectious complications can be serious, requiring prompt management and continued work into preventative strategies.

Touch imprint cytology of prostate core needle biopsy specimens: A useful method for immediate reporting of prostate cancer

Background:

Cytology plays an important role in the preoperative assessment of many cancers. It is used as a first-line pathological investigation in both screening and diagnostic purposes.

Aims:

To determine the diagnostic value and accuracy of touch imprint cytology (TIC) smear of prostate core needle biopsy (CNB) specimens in the diagnosis of prostate carcinoma.

Materials and Methods:

One hundred and twenty-one patients had ultrasound-guided transrectal prostate CNB. A total of 1210 TIC smears were prepared from all CNB specimens.

Results:

Diagnoses of 1210 TIC smears were compared with the histopathological findings of the CNB specimens. One hundred and seventy (14%) TIC smears were found positive for malignancy, 35 (2.9%) were diagnosed as suspicious for malignancy and 1005 (83.1%) were found negative for malignancy. Twenty-five of 35 suspicious imprints and 150 of 170 malignant smears were confirmed to be malignant on histopathological evaluation. Although 20 malignant TIC smears were defined as benign in standard histological preparations, 10 of them had definitive diagnosis of malignancy following extensive serial sectioning. Last of all, there were 10 false-positive cytology results. Moreover, 10 of the 35 suspected TIC smears were false negative when compared with the histopathological diagnosis. The sensitivity, specificity, positive predictive value and negative predictive value of touch imprint smear results were 100%, 98%, 90.2% and 100%, respectively.

Conclusions:

TIC smears can provide an immediate and reliable cytological diagnosis of prostate carcinoma. It may clearly help the rapid detection of carcinoma, particularly in highly suspected cases that had negative routine biopsy results for malignancy with abnormal serum prostate specific antigen (PSA) levels and atypical digital rectal examination.

Evaluating the Prostate Cancer Prevention Trial High Grade Prostate Cancer Risk Calculator in 10 international biopsy cohorts: results from the Prostate Biopsy Collaborative Group

OBJECTIVES

To assess the applicability of the Prostate Cancer Prevention Trial High Grade (Gleason grade ≥ 7) Risk Calculator (PCPTHG) in ten international cohorts, representing a range of populations.

METHODS

A total of 25,512 biopsies from 10 cohorts (6 European, 1 UK and 3 US) were included; 4 implemented 6-core biopsies, and the remaining had 10 or higher schemes; 8 were screening cohorts, and 2 were clinical. PCPTHG risks were calculated using prostate-specific antigen, digital rectal examination, age, African origin and history of prior biopsy and evaluated in terms of calibration plots, areas underneath the receiver operating characteristic curve (AUC) and net benefit curves.

RESULTS

The median AUC of the PCPTHG for high-grade disease detection in the 10- and higher-core cohorts was 73.5% (range, 63.9-76.7%) compared with a median of 78.1% (range, 72.0-87.6%) among the four 6-core cohorts. Only the 10-core Cleveland Clinic cohort showed clear evidence of under-prediction by the PCPTHG, and this was restricted to risk ranges less than 15%. The PCPTHG demonstrated higher clinical net benefit in higher-core compared with 6-core biopsy cohorts, and among the former, there were no notable differences observed between clinical and screening cohorts, nor between European and US cohorts.

CONCLUSIONS

The PCPTHG requires minimal patient information and can be applied across a range of populations. PCPTHG risk thresholds ranging from 5 to 20%, depending on patient risk averseness, are recommended for clinical prostate biopsy decision-making.

A Study of Needle Image Artifact Localization in Confirmation Imaging of MRI-guided Robotic Prostate Biopsy

Recently several systems for magnetic resonance image (MRI) guided needle placement in the prostate have been reported. In comparison to conventional ultrasound-guided needle placement in the prostate, these MRI-guided systems promise improved targeting accuracy for prostate intervention procedures including biopsy, fiducial marker insertion, injection and focal therapy. In MRI-guided needle interventions, after a needle is inserted, the needle position is often confirmed with a volumetric MRI scan. Commonly used titanium needles are not directly visible in an MR image, but they generate a susceptibility artifact in the immediate neighborhood of the needle. This paper reports the results of a quantitative study of the relation between the true position of titanium biopsy needle and the corresponding needle artifact position in MR images. The titanium needle artifact was found to be displaced 0.38 mm and 0.32 mm shift in scanner's frequency and phase encoding direction, respectively. The artifact at the tip of the titanium needle was observed to bend toward the scanner's B(0) magnetic field direction.

Comparison of 12-core versus 8-core prostate biopsy: multivariate analysis of large series of US veterans

OBJECTIVES

To investigate the impact of additional biopsy cores on prostate cancer diagnosis among US veterans. The reported rate of positive biopsy results varies from 20% to 40%.

METHODS

We analyzed 1546 consecutive initial prostate biopsy procedures (8-core and 12-core biopsy protocols) at the Atlanta VA Medical Center. Both biopsy protocols targeted the peripheral zone. Cancer detection rates were compared between the 2 protocols in univariate and multivariate analyses with results expressed as odds ratios and corresponding 95% confidence intervals. Characteristics of cancer detected were also compared. Sensitivity analyses were performed for different population subgroups.

RESULTS

The overall positive biopsy rate was 49.9%, 51.2% in the 8-core group and 49.2% in the 12-core group. There was no difference between the 2 biopsy groups (adjusted odds ratio = 0.97, 95% confidence interval = 0.76-1.25). Advanced age and high body mass index were significantly associated with higher likelihood of prostate cancer, whereas larger prostate volumes were associated with lower risk.

CONCLUSIONS

In this large series of prostate biopsy procedures, in which the peripheral zone was well targeted, there was no evidence that 12-core biopsy improved the likelihood of prostate cancer diagnosis compared with 8-core biopsy. As such, the results of this cohort from a US veteran population suggest that targeting the peripheral zone is more important than the absolute number of biopsy cores. However, in certain subgroups of patients with specific clinical characteristics, such as those with very large prostates, more cores may be required. Further studies are needed to identify such characteristics.

Single positive core prostate cancer in a 12-core transrectal biopsy scheme: clinicopathological implications compared with multifocal counterpart

Purpose

The incidence of single positive core prostate cancer at the time of biopsy appears to be increasing in the prostate-specific antigen (PSA) era. To determine the clinical implication of this disease, we analyzed surgical and pathological characteristics in comparison with multiple positive core disease.

Materials and Methods

Among 108 consecutive patients who underwent robotic radical prostatectomy following a diagnosis of prostate cancer based on a 12-core transrectal biopsy performed by the same method in a single institute, outcomes from 26 patients (Group 1) diagnosed on the basis of a single positive biopsy core and from 82 patients (Group 2) with multiple positive biopsy cores were analyzed.

Results

The preoperative PSA value, Gleason score, prostate volume, and D'Amico's risk classification of each group were similar. The proportion of intermediate+highrisk patients was 69.2% in Group 1 and 77.9% in Group 2 (p=0.22). Total operative time and blood loss were similar. Based on prostatectomy specimens, only 3 patients (11.5%) in Group 1 met the criteria for an indolent tumor (7.31% in Group 2). Although similarities were observed during preoperative clinical staging (p=0.13), the final pathologic stage was significantly higher in Group 2 (p=0.001). The positive-margin rate was also higher in Group 2 (11.5% vs. 31.7%, p=0.043). Despite similarity in upstaging after prostatectomy in each group (p=0.86), upgrading occurred more frequently in Group 1 (p=0.014, 42.5% vs. 19.5%). No clinical parameters were valuable in predicting upgrading.

Conclusions

Most single positive core prostate cancer diagnoses in 12-core biopsy were clinically significant with similar risk stratification to multiple positive core prostate cancers. Although the positive-margin rate was lower than in multiple positive core disease, an increase in Gleason score after radical prostatectomy occurred more frequently.

The impact of core biopsy fragmentation in prostate cancer

OBJECTIVES

Since accurate tumor localization and quantification are essential requisites avoiding prostate cancer overtreatment, we analyzed the impact of core fragmentation and the relation between core biopsy taken and pathological information in regard to cancer extension and aggressiveness (Gleason score).

METHODS

One hundred and ninety-nine men submitted to trans-rectal prostate biopsy by the same urologist between October 2006 and October 2008 were included, and the number of cores obtained by biopsy compared to the number of cores examined by the same pathologist.

RESULTS

Total core number obtained by biopsy was 21.54 (± 3.56) compared to 24.08 (± 4.77) examined by the pathologist, P < 0.01. Dividing prostate gland by areas such as base, mid and apical right and left, all areas showed statistically different core number between biopsy and pathological examination report (P < 0.01). Mean ratio of positive core cancer length was 0.41 (± 0.12) and 0.32 (± 0.8) comparing individual and overall cores analysis, respectively (P < 0.01). The mean Gleason score in the individual and overall cores analysis were 6.6 (6-9) and 6.3 (6-9), respectively, P < 0.01.

CONCLUSIONS

Considering the ongoing trend for earlier diagnosis of increasing numbers of younger men with low-risk prostate cancer, this study is original and demonstrates the possibility of core fragmentation, explaining in part over- and under-staging. One core per container and an overall Gleason score and percentage of adenocarcinoma for each container are encouraged.

A comparison of the diagnostic performance of systematic versus ultrasound-guided biopsies of prostate cancer

Transrectal ultrasound (TRUS) is an important tool for urologists and radiologists in the detection of prostate cancer. Various TRUS-guided biopsy techniques are applied in clinical practice. Frequently, only the detection rates achieved with these methods are compared. Other diagnostic performance parameters, particularly the specificity and negative predictive value, are seldom compared. After extensive assessment of the available literature, this review describes the methods of TRUS-guided biopsy for prostate cancer detection. A distinction was made between systematic biopsies and biopsies that target a perceived (hypoechoic or Doppler-enhancing) lesion on imaging. Subsequently, the diagnostic performance (sensitivity, specificity, positive and negative predictive values, accuracies) was compared between these techniques. Imaging-guided biopsy showed better diagnostic performance than systematic biopsy with higher sensitivity. The combinations of sensitivity and specificity were highest for colour Doppler and contrast-enhanced targeted biopsy. Studies targeting hypoechoic lesions had relatively high sensitivity, but specificity was low. Presently however, with widespread prostate-specific antigen screening, fewer prostate cancers are hypoechoic, and the value of targeting hypoechoic lesions has diminished. Performing colour or contrast-enhanced Doppler biopsy or adding these techniques to systematic biopsies improves diagnostic performance, particularly by increasing sensitivity.