Assessment of Needle Tip Deflection During Transrectal Guided Prostate Biopsy: Implications for Targeted Biopsies

Enhancing Prostate Cancer Detection Accuracy in Magnetic Resonance Imaging-targeted Prostate Biopsy: Optimizing the Number of Cores Taken

Background and objective

The shift toward targeted biopsy (TBx) aims at enhancing prostate cancer (PCa) detection while reducing overdiagnosis of clinically insignificant disease. Despite the improved ability of TBx in identifying clinically significant PCa (csPCa), the optimal number and location of targeted cores remain unclear. This review aims to assess the optimal number of prostate biopsy magnetic resonance imaging (MRI)-targeted cores to detect csPCa.

Methods

A narrative literature search was conducted using PubMed, focusing on studies published between January 2014 and January 2024, addressing factors influencing targeted core numbers during prostate biopsy. The search included both retrospective and prospective studies, prioritizing those with substantial sample sizes and employing terms such as "prostate biopsy", "mpMRI", "core number", and "cancer detection".

Key findings and limitations

Two biopsy cores identified csPCa in 55-65% of cases. This detection rate improved to approximately 90% when the number of cores was ≥5. The inclusion of perilesional and systematic biopsies could maximize the detection of csPCa (from 10% to 45%), especially in patients under active surveillance or with prior negative biopsy results, although there is an increase in the overdiagnosis of indolent tumors (from 4% to 20%). Transperineal software-assisted target prostate biopsy may enhance cancer detection, particularly for tumors located at the apex/anterior part of the prostate. Increasing the number of TBx cores may incrementally raise the risk of complications (by 2-14% with each added core) and result in severe pain and significant discomfort for up to 17% and 25% of TBx patients, respectively. However, the overall rate and severity of these complications remain within acceptable limits.

Conclusions and clinical implications

The optimal number of cores for targeted prostate biopsies should balance minimizing sampling errors with effective cancer detection and should be tailored to each patient's unique prostate characteristics. Up to five cores per MRI target may be considered to enhance the detection of csPCa, with adjustments based on factors such as prostate and lesion volume, Prostate Imaging Reporting and Data System, biopsy techniques, complications, patient discomfort, and anxiety.

Patient summary

In this report, we found that increasing the number of biopsy cores up to ≥5 improves the detection rates of significant prostate cancer significantly to around 90%. Although inclusion of nearby and systematic biopsies enhances detection, increasing the biopsy count may lead to higher risks of complications and indolent tumors. A customized biopsy approach based on multiple variables could be helpful in determining the appropriate number of targeted biopsies on a case-by-case basis.

Transperineal magnetic resonance imaging targeted biopsy versus transrectal route in the detection of prostate cancer: a systematic review and meta-analysis

PURPOSE

Magnetic resonance imaging (MRI) has deeply altered the prostate biopsy strategy to detect prostate cancer. However, it is still debatable whether the detection rate differs between transrectal (TR) and transperineal (TP) MRI-targeted biopsy (MRI-TB). To compare the effectiveness of these two methods for detecting both overall prostate cancer (PCa) and clinically significant PCa (csPCa), We performed a review and meta-analysis.

METHODS

Until January 2023, we conducted a thorough search of Cochrane, Embase, Ovid, and PubMed. In total, 1482 references were identified, and 15 records were finally included. For PCa and csPCa discovered by TP and TR MRI-TB, we combined the relative sensitivity (RR) with 95% confidence intervals (CI). The RR between the TP and TR routes was established.

RESULTS

Our study included 8826 patients in total and revealed that TP MRI-TB detected more PCa (RR 1.25 [95% CI 1.12, 1.39], p < 0.0001). In patients who underwent TP MRI-TB and TR MRI-TB at the same time or separately, TP MRI-TB had a greater detection rate of csPCa in per-patient analysis (one cohort (RR 1.33 [95% CI 1.09, 1.63], p = 0.005); two cohorts (RR 1.37 [95% CI 1.16, 1.61], p  = 0.0002)). However, the detection rate of csPCa between the TP route and the TR route was comparable in per-lesion analysis (RR 0.91 [95% CI 0.76, 1.08], p  = 0.28). Additionally, in the prostate's anterior region, we found that TP MRI-TB detected more csPCa (per-lesion (RR 1.52 [95% CI 1.04, 2.23], p  = 0.03); per-patient (RR 2.55 [95% CI 1.56, 4.16], p  = 0.0002)).

CONCLUSION

According to this comprehensive study, TP MRI-TB is more effective than TR MRI-TB at detecting PCa and csPCa. Significant results persisted for detecting csPCa located in the anterior zone. The results need to be taken carefully notwithstanding the heterogeneity among the included studies.

Evaluating the Learning Curve for In-office Freehand Cognitive Fusion Transperineal Prostate Biopsy

OBJECTIVE

To define the learning curve of the in-office, freehand MRI-ultrasound cognitive fusion transperineal prostate biopsy (CTPB) by assessing cancer detection, biopsy core quantity and quality, procedure times, and complications over the initial experience.

METHODS

We reviewed 110 consecutive CTPB performed March 2021-September 2022 by a urologist inexperienced with the PrecisionPoint platform. The study period was divided into quarters to assess for temporal variation in outcomes. Univariable and multivariable analysis modeled the learning curve.

RESULTS

Across quarters, there were no differences in the detection of clinically significant prostate cancer (Q1:50%, Q2:52%, Q3:50%, Q4:48%, P > .9) or Gleason grade group upgrading by targeted vs systematic biopsy (P = .6). Median procedure times improved with experience (Q1:17 minutes, Q2:14 minutes, Q3:12 minutes, Q4:13 minutes, P = .018). On multivariable analysis, procedure times decreased by 1minute per 20 cases (P < .001). On linear regression, CTPB procedure times approximated transrectal biopsy times after 90 cases (P < .001). The histopathologic core quality did not differ, as evidenced by consistent core length (P = .13) and presence of minimal fibromuscular tissue (P > .9). The most common complications, hematuria and hematospermia, were similar across quarters (P = .7, P = .3, respectively). There was a single episode of urinary retention and no reported infections.

CONCLUSION

There is no evidence of a learning curve for CTPB as shown by consistent clinically significant prostate cancer detection, high-quality biopsy cores, and low complications. However, CTPB procedural times begin to approximate cognitive targeted transrectal biopsy times after 90 cases.

Combination of fusion guided multiparametric MRI-transrectal US with systematic biopsy of the prostate for the detection of clinically significant prostate cancer: A prospective single-center study

PURPOSE

To investigate the diagnostic efficacy of fusion guided multiparametric MRI (mpMRI)-transrectal ultrasound (TRUS) biopsy versus systematic biopsy of the prostate in patients with suspicion of prostate cancer.

METHODS

A total of 185 patients with PI-RADS 3 lesions or higher underwent fusion guided targeted and systematic prostate biopsy. Histology of samples was correlated with PI-RADS score and biopsy method for each patient.

RESULTS

A total of 81/185 (43.8%) cases positive for cancer were detected; 23/81 (28.4%) cases with clinically insignificant prostate cancer-insPCa and 58/81 (71.6%) cases with clinically significant prostate cancer-csPCa. There was a statistically significant difference in the overall detection of adenocarcinomas between methods (p = .035, McNemar test). Moreover, there was a statistically significant difference in the detection of insPCa between the two methods (p = .004, McNemar test). Systematic biopsy detected 13 patients with insPCa more (14.4%) than the targeted biopsy method. However, there is no statistical difference in the detection rate of csPCa between the two methods (p = 1, McNemar test). When both techniques were combined more cases of csPCa were detected.

CONCLUSION

The combined implementation of fusion-guided targeted mpMRI-TRUS and systematic biopsy of the prostate provides higher detection number of csPCa, compared to each method alone. The potential of fusion-guided mpMRI-TRUS biopsy of the prostate needs to be further assessed since each method has its limitations; therefore, systematic prostate biopsy still plays an important role in clinical practice.

MRI-informed prostate biopsy: What the radiologist should know on quality in biopsy planning and biopsy acquisition

Quality is currently recognized as the pre-requisite for delivering the clinical benefits expected by magnetic resonance imaging (MRI)-informed prostate biopsy (MRI-i-PB) in patients with a suspicion for clinically significant prostate cancer (csPCa). The "quality chain" underlying MRI-i-PB is multidisciplinary in nature, and depends on several factors related to the patient, imaging technique, image interpretation and biopsy procedure. This review aims at making the radiologist aware of biopsy-related factors impacting on MRI-i-PB quality, both in terms of biopsy planning (threshold for biopsy decisions, association with systematic biopsy and number of targeted cores) and biopsy acquisition (biopsy route, targeting technique, and operator's experience). While there is still space for improvement and better standardization of several biopsy-related procedures, current evidence suggests that high-quality MRI-i-PB can be delivered by acquiring and increased the number of biopsy cores targeted to suspicious imaging findings and perilesional area ("focal saturation biopsy"). On the other hand, uncertainty still exists as to whether software-assisted fusion of MRI and transrectal ultrasound images can outperform cognitive fusion strategy. The role for operator's experience and quality assurance/quality control procedures are also discussed.

Comparison of transperineal and transrectal targeted prostate biopsy using Mahalanobis distance matching within propensity score caliper method: A multicenter study of Turkish Urooncology Association

OBJECTIVE

To compare the clinically significant prostate cancer (csPC)-detecting results of transperineal and transrectal targeted biopsy (TPTB and TRTB, respectively) by performing matching analysis.

PATIENTS AND METHODS

This study has used the PC and prostate biopsy database from the Turkish Urooncology Association. A total of 1143 patients with Prostate Imaging-Reporting and Data System (PI-RADS) with ≥3 lesions on multiparametric magnetic resonance imaging (mpMRI) and who had received a software-guided transperineal/transrectal MRI/transrectal ultrasound (TRUS) fusion prostate biopsy with concomitant standard systematic 12-core biopsy were included in this study. csPC detection rates of the TP and TR approaches were compared following Mahalanobis distance matching within propensity score caliper method. The following four variables were selected as covariates for the matching procedure: age, digital rectal examination findings, PSA density, and the index lesion PI-RADS score.

RESULTS

The matched sample included 508 TR and 276 TP patients. In both the TP and the TR groups, targeted biopsy was superior to systematic biopsy in detecting csPC (27.5% vs. 24.6%, p < 0.001 and 19.5% vs. 16.3%, p < 0.0001, respectively). Both TPTB and TP systematic biopsy was found to be superior to TRTB and TR systematic biopsy in terms of csPC detection (27.5% vs. 19.5%, p = 0.012 and 24.6% vs. 16.3%, p = 0.006). In patients with an anterior index lesion, an apical index lesion, and a larger prostate, the superiority of TPTB to TRTB was found to be more prominent in terms of csPC detection (37.8% vs. 18.3%, p = 0.044; 34.6% vs. 14.7%, p = 0.002; and 25% vs. 5.1%, p = 0.033, respectively).

CONCLUSION

Targeted biopsy was found to be superior to systematic biopsy in detecting csPC in both the TP and the TR approaches. The TP approach is preferred because of its clear superiority in detecting csPC in targeted biopsy, especially in patients with anterior and apical lesions and with larger prostates.

Multi-Bevel Needle Design Enabling Accurate Insertion in Biopsy for Cancer Diagnosis

OBJECTIVE

To obtain definitive cancer diagnosis for suspicious lesions, accurate needle deployment and adequate tissue sampling in needle biopsy are essential. However, the single-bevel needles in current biopsy devices often induce deflection during insertion, potentially causing lesion missampling/undersampling and cancer misdiagnosis. This study aims to reveal the biopsy needle design criteria enabling both low deflection and adequate tissue sampling.

METHODS

A novel model capable of predicting needle deflection and tissue deformation was first established to understand needle-tissue interaction with different needle tip geometries. Experiments of needle deflection and ex-vivo tissue biopsy were conducted for model validation.

RESULTS

The developed model showed a reasonably good prediction on the correlation of needle tip type vs. the resultant needle deflection and tissue sampling length. A new multi-bevel needle with the tissue separation point below the needle groove face has demonstrated to be an effective design with an 87% reduction in deflection magnitude and equivalently long tissue sampling length compared to the current single-bevel needle.

CONCLUSION

This study has revealed two critical design criteria for biopsy needles: 1) multiple bevel faces at the needle tip can generate forces to balance bending moments during insertion to enable a low needle deflection and 2) the tissue separation point should be below the needle groove face to ensure long tissue sampling length.

SIGNIFICANCE

The developed methodologies and findings in this study serve as proof-of-concept and can be utilized to investigate various biopsy procedures to improve cancer diagnostic accuracy as well as other procedures requiring accurate needle insertion.

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.

Probability of Prostate Cancer Diagnosis following Negative Systematic and Targeted MRI: Transrectal Ultrasound Fusion Biopsy: A Real-Life Observational Study

INTRODUCTION

The risk of occult prostate carcinoma (PCa) after negative multiparametric MRI (mpMRI)-transrectal fusion biopsy (F-Bx) is unknown. To determine the false-negative predictive value, we examined PCa detection after prior negative F-Bx.

METHODS

Between December 2012 and November 2016, 491 patients with suspected PCa and suspicious mpMRI findings underwent transrectal F-Bx. Patients with benign pathology (n = 191) were eligible for our follow-up (FU) survey. Patient characteristics and clinical parameters were correlated to subsequent findings of newly detected PCa.

RESULTS

Complete FU with a median of 31 (interquartile range: 17-39) months was available for 176/191 (92.2%) patients. Of those, 54 men had either surgical interventions on the prostate or re-Bxs. Newly detected PCa was evident in 14/176 (7.95%) patients stratified to ISUP ≤2 in 10 and ≥3 in 4 cases. The comparison of patients with newly detected PCa to those without cancerous findings in FU showed significant differences in prostate-specific antigen (PSA) density (0.16 vs. 0.13 ng/mL2) and prostate volume (45 vs. 67 mL, both p < 0.05). Both factors are significant predictors for newly detected cancer after initial negative F-Bx.

CONCLUSION

Only PSA density (>0.13 ng/mL2) and small prostate volume are significant predictors for newly detected PCa after initial negative F-Bx. Despite negative mpMRI/TRUS F-Bx results, patients should be further monitored due to a risk of developing PCa over time. Notwithstanding the limitation of our study that not all patients underwent another Bx, we assume that the false-negative rate is low but existing. Our data represent a real-world scenario.

Mosquito proboscis-inspired needle insertion to reduce tissue deformation and organ displacement

This study investigates mosquito proboscis-inspired (MPI) insertion applied to the clinically used biopsy needle to reduce tissue deformation and organ displacement. Advanced medical imagining has enabled early-stage identification of cancerous lesions that require needle biopsy for minimally invasive tissue sampling and pathological analysis. Accurate cancer diagnosis depends on the accuracy of needle deployment to the targeted cancerous lesion site. However, currently available needle delivery systems deform and move soft tissue and organs, leading to a non-diagnostic biopsy or undersampling of the target. Two features inspired by the mosquito proboscis were adopted for MPI insertion in prostate biopsy: (1) the harpoon-shape notches at the needle tip and (2) reciprocating needle-cannula motions for incremental insertion. The local tissue deformation and global prostate displacement during the MPI vs. traditional direct insertions were quantified by optically tracking the displacement of particle-embedded tissue-mimicking phantoms. Results show that the MPI needle insertion reduced both local tissue deformation and global prostate displacement because of the opposite needle-cannula motions and notches which stabilized and reduced the tissue deformation during insertion. Findings provide proof of concept for MPI insertion in the clinical biopsy procedures as well as insights of needle–tissue interaction for future biopsy technology development.

A noninferiority within-person study comparing the accuracy of transperineal to transrectal MRI-US fusion biopsy for prostate-cancer detection

BACKGROUND

Magnetic resonance imaging (MRI) and ultrasound (US) fusion prostate-biopsies can be performed in a transrectal (TR-fusion) or transperineal (TP-fusion) approach. Prospective comparative evidence is limited. In this study we compared the detection rate of clinically-significant prostate-cancer (csPCa) within an index lesion between TR and TP-fusion.

PATIENTS AND METHODS

This was a prospective, noninferiority, and within-person trial. Men scheduled for MRI-US-fusion with a discrete MRI PI-RRAD ≥ 3 lesion were included. A dominant index lesion was determined for each subject and sampled by TR and TP-fusion during the same session. The order of biopsies was randomized and equipment was reset to avoid chronological and incorporation bias. For each subject, the index lesion was sampled 4-6 times in each approach. All biopsies were performed using Navigo fusion software (UC-Care, Yokneam, Israel). csPCa was defined as: Grade Group ≥ 2 or cancer-core length ≥ 6 mm. We used a noninferiority margin of 10% and a one-sided alpha level of 5%.

RESULTS

Seventy-seven patients completed the protocol. Median age was 68.2 years (IQR:64.2-72.2), median PSA was 8.9 ng/ml (IQR:6.18-12.2). Ten patients (13%) were biopsy naive, others (87%) had a previous biopsy. csPCa was detected in 32 patients (42%). All of these cases were detected by TP-fusion, while only 20 (26%) by TR-fusion. Absolute difference for csPCa diagnosis was 15.6 (CI 90% 27.9-3.2%) in favor of TP-fusion (p = 0.029). TP-fusion was noninferior to TR-fusion. The lower boundary of the 90% confidence-interval between TP-fusion and TR-fusion was greater than zero, therefore TP-fusion was also found to be superior. Exploratory subgroup analyses showed TP-fusion was consistently associated with higher detection rates of csPCa compared with TR-fusion in patient and index-lesion derived subgroups (size, location, PI-RADS, PSA, and biopsy history).

CONCLUSIONS

In this study, TP-fusion biopsies were found to be noninferior and superior to TR-fusion biopsies in detecting csPCa within MRI-visible index lesion. Centers experienced in both TP and TR-fusion should consider these results when choosing biopsy method.

Needle deflection and tissue sampling length in needle biopsy

This study investigates the effect of needle tip geometry on the needle deflection and tissue sampling length in biopsy. Advances in medical imaging have allowed the identification of suspicious cancerous lesions which then require needle biopsy for tissue sampling and subsequent confirmatory pathological analysis. Precise needle insertion and adequate tissue sampling are essential for accurate cancer diagnosis and individualized treatment decisions. However, the single-bevel needles in current hand-held biopsy devices often deflect significantly during needle insertion, causing variance in the targeted and actual locations of the sampled tissue. This variance can lead to inaccurate sampling and false-negative results. There is also a limited understanding of factors affecting the tissue sampling length which is a critical component of accurate cancer diagnosis. This study compares the needle deflection and tissue sampling length between the existing single-bevel and exploratory multi-bevel needle tip geometries. A coupled Eulerian-Lagrangian finite element analysis was applied to understand the needle-tissue interaction during needle insertion. The needle deflection and tissue sampling length were experimentally studied using tissue-mimicking phantoms and ex-vivo tissue, respectively. This study reveals that the tissue separation location at the needle tip affects both needle deflection and tissue sampling length. By varying the tissue separation location and creating a multi-bevel needle tip geometry, the bending moments induced by the insertion forces can be altered to reduce the needle deflection. However, the tissue separation location also affects the tissue contact inside the needle groove, potentially reducing the tissue sampling length. A multi-bevel needle tip geometry with the tissue separation point below the needle groove face may reduce the needle deflection while maintaining a long tissue sampling length. Results from this study can guide needle tip design to enable the precise needle deployment and adequate tissue sampling for the needle biopsy procedures.

Needle Biopsy Adequacy in the Era of Precision Medicine and Value-Based Health Care

CONTEXT.—

Needle biopsy of diseased tissue is an essential diagnostic tool that is becoming even more important as precision medicine develops. However, the capability of this modality to efficiently provide samples adequate for diagnostic and prognostic analysis remains quite limited relative to current diagnostic needs. For physicians and patients, inadequate biopsy frequently leads to diagnostic delay, procedure duplication, or insufficient information about tumor biology leading to delay in treatment; for health systems, this results in substantial incremental costs and inefficient use of scarce specialized diagnostic resources.

OBJECTIVE.—

To review current needle biopsy technology, devices, and practice with a perspective to identify current limitations and opportunities for improvement in the context of advancing precision medicine.

DATA SOURCES.—

PubMed searches of fine-needle aspiration and core needle biopsy devices and similar technologies were made generally, by tissue site, and by adequacy as well as by health economics of these technologies.

CONCLUSIONS.—

Needle biopsy adequacy can be improved by recognizing the importance of this diagnostic tool by promoting common criteria for needle biopsy adequacy; by optimizing needle biopsy procedural technique, technologies, clinical practice, professional education, and quality assurance; and by bundling biopsy procedure costs with downstream diagnostic modalities to provide better accountability and incentives to improve the diagnostic process.

Follow-up of negative MRI-targeted prostate biopsies: when are we missing cancer?

INTRODUCTION

Multiparametric magnetic resonance imaging (mpMRI) has improved clinicians' ability to detect clinically significant prostate cancer (csPCa). Combining or fusing these images with the real-time imaging of transrectal ultrasound (TRUS) allows urologists to better sample lesions with a targeted biopsy (Tbx) leading to the detection of greater rates of csPCa and decreased rates of low-risk PCa. In this review, we evaluate the technical aspects of the mpMRI-guided Tbx procedure to identify possible sources of error and provide clinical context to a negative Tbx.

METHODS

A literature search was conducted of possible reasons for false-negative TBx. This includes discussion on false-positive mpMRI findings, termed "PCa mimics," that may incorrectly suggest high likelihood of csPCa as well as errors during Tbx resulting in inexact image fusion or biopsy needle placement.

RESULTS

Despite the strong negative predictive value associated with Tbx, concerns of missed disease often remain, especially with MR-visible lesions. This raises questions about what to do next after a negative Tbx result. Potential sources of error can arise from each step in the targeted biopsy process ranging from "PCa mimics" or technical errors during mpMRI acquisition to failure to properly register MRI and TRUS images on a fusion biopsy platform to technical or anatomic limits on needle placement accuracy.

CONCLUSIONS

A better understanding of these potential pitfalls in the mpMRI-guided Tbx procedure will aid interpretation of a negative Tbx, identify areas for improving technical proficiency, and improve both physician understanding of negative Tbx and patient-management options.