Value of systematic sampling in an mp-MRI targeted prostate biopsy strategy

The initial results of MRI-TRUS fusion prostate biopsy in high volume tertiary center

BACKGROUND

Multiparametric magnetic resonance imaging (mpMRI) is a prerequisite for targeted prostate biopsy. The aim of our study was to evaluate the performance and learning curve of the mpMRI-transrectal ultrasound (TRUS) software image fusion (MRI-TRUS fusion) biopsy (BX) process in the first year after its introduction in our urology department.

PATIENTS AND METHODS

MRI-TRUS fusion BX was performed in 293 patients with at least one Prostate Imaging-Reporting and Data System (PIRADS) ≥3 lesion. The proportion of patients and lesions with positive histopathologic result for prostate cancer (PCa) was analyzed. The learning curve for MRI-TRUS fusion BX was assessed at institutional and individual level. Positive BX lesions were further analyzed by PIRADS and Gleason scores.

RESULTS

The proportion of patients with positive histopathologic results for targeted BX, systematic BX, and combined BX was 53.9%, 47.9%, and 63.5%, respectively. The chi-square test for the proportion of PCa positive patients showed no significant difference between the time-based patient groups at the institutional level and no significant difference between individual urologists. PIRADS score (p < 0.001), total PSA concentration (p = 0.05), prostate volume (p < 0.001) and number of cores per lesion (p = 0.034) were significant predictors of a positive histopathologic result in a lesion-based analysis. Clinically significant PCa (csPCa) was confirmed in 34.7% of the 412 BX lesions and 76.4% of the 187 positive PCa lesions.

CONCLUSIONS

MRI-TRUS fusion targeted BX significantly improves the overall rate of PCa detection compared with systematic BX alone. No steep learning curve was observed in our urologists. The proportion of lesions with clinically insignificant PCa was low, limiting overdiagnosis of PCa.

Added value of randomised biopsy to multiparametric magnetic resonance imaging-targeted biopsy of the prostate in a contemporary cohort

OBJECTIVE

To assess the added value of concurrent systematic randomised ultrasonography-guided biopsy (SBx) to multiparametric magnetic resonance imaging (mpMRI)-targeted biopsy and the additional rate of overdiagnosis of clinically insignificant prostate cancer (ciPCa) by SBx in a large contemporary, real-world cohort.

PATIENTS AND METHODS

A total of 1552 patients with positive mpMRI and consecutive mpMRI-targeted biopsy and SBx were enrolled. Added value and the rate of overdiagnosis by SBx was evaluated.

PRIMARY OUTCOME

added value of SBx, defined as detection rate of clinically significant PCa (csPCa; International Society of Urological Pathology [ISUP] Grade ≥2) by SBx, while mpMRI-targeted biopsy was negative or showed ciPCa (ISUP Grade 1).

SECONDARY OUTCOME

rate of overdiagnosis by SBx, defined as detection of ciPCa in patients with negative mpMRI-targeted biopsy and PSA level of <10 ng/mL.

RESULTS

Detection rate of csPCa by mpMRI-targeted biopsy and/or SBx was 753/1552 (49%). Added value of SBx was 145/944 (15%). Rate of overdiagnosis by SBx was 146/656 (22%). Added value of SBx did not change when comparing patients with previous prostate biopsy and biopsy naïve patients. In multivariable analysis, a Prostate Imaging-Reporting and Data System (PI-RADS) 4 index lesion (odds ratio [OR] 3.19, 95% confidence interval [CI] 1.66-6.78; P = 0.001), a PI-RADS 5 index lesion (OR 2.89, 95% CI 1.39-6.46; P = 0.006) and age (OR 1.05, 95% CI 1.03-1.08; P < 0.001) were independently associated with added value of SBx.

CONCLUSIONS

In our real-world analysis, we saw a significant impact on added value and added rate of overdiagnosis by SBx. Subgroup analysis showed no significant decrease of added value in any evaluated risk group. Therefore, we do not endorse omitting concurrent SBx to mpMRI-guided biopsy of the prostate.

An improved version of systematic sampling design for use with linear trend data

In survey sampling, systematic sampling design has attracted survey researchers in recent years due to its simplicity of use. We introduce a modified variant of systematic sampling scheme which improves the efficiency of a recently developed diagonal systematic sampling method. The suggested modification is also found to be more efficient than the other popular sampling designs in circumstances where the units of the population under consideration exhibit an increasing or decreasing perfect or near-perfect linear trend. Moreover, it is observed that the conditions for efficiency are mathematically strong and practically always hold, hence making the suggested sampling design preferable over the available sampling designs.

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.

Landmarks in the evolution of prostate biopsy

Approaches and techniques used for diagnostic prostate biopsy have undergone considerable evolution over the past few decades: from the original finger-guided techniques to the latest MRI-directed strategies, from aspiration cytology to tissue core sampling, and from transrectal to transperineal approaches. In particular, increased adoption of transperineal biopsy approaches have led to reduced infectious complications and improved antibiotic stewardship. Furthermore, as image fusion has become integral, these novel techniques could be incorporated into prostate biopsy methods in the future, enabling 3D-ultrasonography fusion reconstruction, molecular targeting based on PET imaging and autonomous robotic-assisted biopsy.

Clinical and pathologic characteristics to select patients for focal therapy or partial gland ablation of nonmetastatic prostate cancer

PURPOSE OF REVIEW

Focal therapy or partial gland ablation for nonmetastatic prostate cancer is gaining popularity not just as an alternative to active surveillance, but as an acceptable alternative to whole gland therapy in appropriate cases. This review summarizes recent evidence to help select patients for optimal outcomes.

RECENT FINDINGS

Recommendations by expert panels have become less conservative with each meeting. As experience with older modalities for focal therapy grows, newer modalities continue to be introduced. We are now in a position to offer personalized treatment pathway considering nuances of each focal therapy modality.

SUMMARY

The ideal case for focal therapy should be an MRI visible significant lesion (PIRADS score ≥ 3), with a positive biopsy for significant cancer (Gleason grade group 2-3) in the corresponding targeted biopsy area, and insignificant or absent disease in the nontarget random biopsy areas. Multifocal disease can also be selectively treated. Salvage focal ablation is an attractive treatment option for radio-recurrent or index focal therapy failure cases.

Predicting the Performance of Concurrent Systematic Random Biopsies during Image Fusion Targeted Sampling of Multi-Parametric MRI Detected Prostate Cancer. A Prospective Study (PRESET Study)

Simple Summary

The study provides a predictive model by using clinical factors in selecting men who may benefit from the addition of systematic biopsies with an image fusion targeted approach. The approach is likely to improve the detection of csPCa and avoid unnecessary detection of indolent prostate cancers.

Abstract

The study was aimed to develop a predictive model to identify patients who may benefit from performing systematic random biopsies (SB) in addition to targeted biopsies (TB) in men suspected of having prostate cancer. A total of 198 patients with positive pre-biopsy MRI findings and who had undergone both TB and SB were prospectively recruited into this study. The primary outcome was detection rates of clinically significant prostate cancer (csPCa) in SB and TB approaches. The secondary outcome was net clinical benefits of SB in addition to TB. A logistic regression model and nomogram construction were used to perform a multivariate analysis. The detection rate of csPCa using SB was 51.0% (101/198) compared to a rate of 56.1% (111/198) for TB, using a patient-based biopsy approach. The detection rate of csPCa was higher using a combined biopsy (64.6%; 128/198) in comparison to TB (56.1%; 111/198) alone. This was statistically significant (p < 0.001). Age, PSA density and PIRADS score significantly predicted the detection of csPCa by SB in addition to TB. A nomogram based on the model showed good discriminative ability (C-index; 78%). The decision analysis curve confirmed a higher net clinical benefit at an acceptable threshold.

Multiparametric MRI in Active Surveillance of Prostate Cancer: An Overview and a Practical Approach

MRI has become important for the detection of prostate cancer. MRI-guided biopsy is superior to conventional systematic biopsy in patients suspected with prostate cancer. MRI is also increasingly used for monitoring patients with low-risk prostate cancer during active surveillance. It improves patient selection for active surveillance at diagnosis, although its role during follow-up is unclear. We aim to review existing evidence and propose a practical approach for incorporating MRI into active surveillance protocols.

Focal therapy for localized prostate cancer in the era of routine multi-parametric MRI

BACKGROUND

Prostate cancer focal therapy aims to minimize the side-effects of whole gland treatments, such as radical prostatectomy and radiotherapy without compromising oncological efficacy. However, concerns exist regarding the multifocal nature of prostate cancer and the lack of long-term oncological data for this form of treatment. In recent years, the routine adoption of multi-parametric magnetic resonance imaging (mpMRI) of the prostate has improved our ability to select candidates for focal therapy and to accurately deliver this form of prostate cancer treatment.

METHODS

We performed a review of the literature to provide a summary of the oncological and functional outcomes of men receiving primary prostate focal therapy. Furthermore, we discuss the impact of the routine implementation of mpMRI as part of the initial prostate cancer diagnostic pathway on the selection of candidates and delivery of focal therapy. Finally, we summarize knowledge gaps in the field and highlight active clinical trials in this arena.

RESULTS

Primary focal therapy involves the application of one of a number of energies that ablate tissue, such as cryotherapy and high intensity focused ultrasound (HIFU). Success is principally dependent on highly accurate patient selection and disease localization underpinned in large part by the routine integration of pre-biopsy mpMRI. Prospective medium-term follow-up data for primary HIFU and cryotherapy for men with intermediate-risk disease have shown acceptable cancer control with low risk of side effects and complications. Additional research is needed to clearly define an appropriate follow-up approach and to guide the management of in- and out-of-field recurrences. Multiple comparative trials with randomization against standard care are currently underway in men with intermediate- and high-risk prostate cancer.

CONCLUSION

The widespread adoption of prostate mpMRI has led to improved disease localization, enabling the performance of focal therapy as a viable treatment strategy for men with low volume intermediate-risk prostate cancer.