How reliable is 12-core prostate biopsy procedure in the detection of prostate cancer?

High-throughput lipidomic profiles sampled with electroporation-based biopsy differentiate healthy skin, cutaneous squamous cell carcinoma, and basal cell carcinoma

BACKGROUND

The incidence rates of cutaneous squamous cell carcinoma (cSCC) and basal cell carcinoma (BCC) skin cancers are rising, while the current diagnostic process is time-consuming. We describe the development of a novel approach to high-throughput sampling of tissue lipids using electroporation-based biopsy, termed e-biopsy. We report on the ability of the e-biopsy technique to harvest large amounts of lipids from human skin samples.

MATERIALS AND METHODS

Here, 168 lipids were reliably identified from 12 patients providing a total of 13 samples. The extracted lipids were profiled with ultra-performance liquid chromatography and tandem mass spectrometry (UPLC-MS-MS) providing cSCC, BCC, and healthy skin lipidomic profiles.

RESULTS

Comparative analysis identified 27 differentially expressed lipids (p < 0.05). The general profile trend is low diglycerides in both cSCC and BCC, high phospholipids in BCC, and high lyso-phospholipids in cSCC compared to healthy skin tissue samples.

CONCLUSION

The results contribute to the growing body of knowledge that can potentially lead to novel insights into these skin cancers and demonstrate the potential of the e-biopsy technique for the analysis of lipidomic profiles of human skin tissues.

Shifting to transperineal prostate biopsy: A narrative review

To address the limitations and challenges associated with transrectal (TR) biopsy and to present transperineal (TP) biopsy as a viable and potentially safer alternative to TR biopsy. Prostate cancer (PCa) is a significant global health concern. The prevalence of advanced-stage prostate cancer in Asia is higher than that in the United States, emphasizing the need for effective screening and diagnosis methods. The gold standard of diagnosis is a TR biopsy. However, it has limitations due to the risk of infection and potential complications, such as injury to the rectal artery. Efforts have been made to address issues such as false-negative biopsies, under-sampling, and over-sampling through MRI-guided biopsies. However, the TR approach makes it difficult to access the apical and anterior regions of the prostate. TP biopsy has emerged as an alternative to address the limitations of TR biopsy. Nevertheless, a TP biopsy is a painful procedure, requiring the use of general anesthesia and expensive equipment. As a result, it has been perceived as costly and time-consuming. In addition, it requires a steep learning curve. The introduction of local anesthesia such as pudendal nerve block and the adoption of freehand techniques have contributed to the feasibility of performing TP biopsy. Recent research indicates that freehand TP biopsy can yield comparable diagnostic results to template-guided approaches. The diagnostic performance, cancer detection rates, and complication rates of TP biopsy have demonstrated its potential as a safe and effective diagnostic method.

Deep learning based on 68Ga-PSMA-11 PET/CT for predicting pathological upgrading in patients with prostate cancer

Objectives

To explore the feasibility and importance of deep learning (DL) based on 68Ga-prostate-specific membrane antigen (PSMA)-11 PET/CT in predicting pathological upgrading from biopsy to radical prostatectomy (RP) in patients with prostate cancer (PCa).

Methods

In this retrospective study, all patients underwent 68Ga-PSMA-11 PET/CT, transrectal ultrasound (TRUS)-guided systematic biopsy, and RP for PCa sequentially between January 2017 and December 2022. Two DL models (three-dimensional [3D] ResNet-18 and 3D DenseNet-121) based on 68Ga-PSMA-11 PET and support vector machine (SVM) models integrating clinical data with DL signature were constructed. The model performance was evaluated using area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity.

Results

Of 109 patients, 87 (44 upgrading, 43 non-upgrading) were included in the training set and 22 (11 upgrading, 11 non-upgrading) in the test set. The combined SVM model, incorporating clinical features and signature of 3D ResNet-18 model, demonstrated satisfactory prediction in the test set with an AUC value of 0.628 (95% confidence interval [CI]: 0.365, 0.891) and accuracy of 0.727 (95% CI: 0.498, 0.893).

Conclusion

A DL method based on 68Ga-PSMA-11 PET may have a role in predicting pathological upgrading from biopsy to RP in patients with PCa.

Role of radiomic analysis of [18F]fluoromethylcholine PET/CT in predicting biochemical recurrence in a cohort of intermediate and high risk prostate cancer patients at initial staging

AIM

To study the feasibility of radiomic analysis of baseline [18F]fluoromethylcholine positron emission tomography/computed tomography (PET/CT) for the prediction of biochemical recurrence (BCR) in a cohort of intermediate and high-risk prostate cancer (PCa) patients.

MATERIAL AND METHODS

Seventy-four patients were prospectively collected. We analyzed three prostate gland (PG) segmentations (i.e., PGwhole: whole PG; PG41%: prostate having standardized uptake value - SUV > 0.41*SUVmax; PG2.5: prostate having SUV > 2.5) together with three SUV discretization steps (i.e., 0.2, 0.4, and 0.6). For each segmentation/discretization step, we trained a logistic regression model to predict BCR using radiomic and/or clinical features.

RESULTS

The median baseline prostate-specific antigen was 11 ng/mL, the Gleason score was > 7 for 54% of patients, and the clinical stage was T1/T2 for 89% and T3 for 9% of patients. The baseline clinical model achieved an area under the receiver operating characteristic curve (AUC) of 0.73. Performances improved when clinical data were combined with radiomic features, in particular for PG2.5 and 0.4 discretization, for which the median test AUC was 0.78.

CONCLUSION

Radiomics reinforces clinical parameters in predicting BCR in intermediate and high-risk PCa patients. These first data strongly encourage further investigations on the use of radiomic analysis to identify patients at risk of BCR.

CLINICAL RELEVANCE STATEMENT

The application of AI combined with radiomic analysis of [18F]fluoromethylcholine PET/CT images has proven to be a promising tool to stratify patients with intermediate or high-risk PCa in order to predict biochemical recurrence and tailor the best treatment options.

KEY POINTS

• Stratification of patients with intermediate and high-risk prostate cancer at risk of biochemical recurrence before initial treatment would help determine the optimal curative strategy. • Artificial intelligence combined with radiomic analysis of [18F]fluorocholine PET/CT images allows prediction of biochemical recurrence, especially when radiomic features are complemented with patients' clinical information (highest median AUC of 0.78). • Radiomics reinforces the information of conventional clinical parameters (i.e., Gleason score and initial prostate-specific antigen level) in predicting biochemical recurrence.

Comparing 12-core and 20-core biopsy for prostate cancer diagnosis with transperineal MR/US fusion biopsy: assessing the effective number of systemic cores using propensity score matching

PURPOSE

For transperineal (TP) prostate biopsy, target biopsy for visible lesions on MRI is important, but there is no consensus of the number of systemic biopsy cores. Our study aimed to confirm the diagnostic efficiency of 20-core systemic biopsy by comparison with 12-core using propensity score matching (PSM).

METHODS

The 494 patients conducted the naive TP biopsy were retrospectively analyzed. There were 293 patients with 12-core biopsy and 201 patients with 20-core biopsy. PSM was performed for minimizing confounding variables, and the established effects' value was analyzed for 'index-positive or negative' clinically significant prostate cancer (csPCa) (Index means PIRADS Score ≥ 3 on multiparametric prostate MRI).

RESULTS

At 12-core biopsy, there were 126 cases of prostate cancer (43.0%), and 97 cases of csPCa (33.1%). At 20-core biopsy, there were 91 cases (45.3%) and 63 cases (31.3%). After propensity score matching, for index-negative csPCa, the estimated odds ratio was 4.03 (95% CI 1.35-12.09, p value 0.0128), and for index-positive csPCa, the estimated odds ratio was 0.98 (95% CI 0.63-1.52, p value 0.9308).

CONCLUSIONS

The 20-core biopsy did not show a higher detection rate for csPCa in comparison with the 12-core biopsy. However, when MRI did not show a suspicious lesion, 20-core biopsy showed higher odd ratio in comparison with 12-core biopsy. Therefore, if there is a suspicious lesion in MRI, 20-core biopsy is excessive and 12-core biopsy is sufficient. Whereas if there is no suspicious lesion in MRI, it is better to proceed with 20-core biopsy.

MRI-targeted biopsy cores from prostate index lesions: assessment and prediction of the number needed

BACKGROUND

Magnetic resonance imaging (MRI) is used to detect the prostate index lesion before targeted biopsy. However, the number of biopsy cores that should be obtained from the index lesion is unclear. The aim of this study is to analyze how many MRI-targeted biopsy cores are needed to establish the most relevant histopathologic diagnosis of the index lesion and to build a prediction model.

METHODS

We retrospectively included 451 patients who underwent 10-core systematic prostate biopsy and MRI-targeted biopsy with sampling of at least three cores from the index lesion. A total of 1587 biopsy cores were analyzed. The core sampling sequence was recorded, and the first biopsy core detecting the most relevant histopathologic diagnosis was identified. In a subgroup of 261 patients in whom exactly three MRI-targeted biopsy cores were obtained from the index lesion, we generated a prediction model. A nonparametric Bayes classifier was trained using the PI-RADS score, prostate-specific antigen (PSA) density, lesion size, zone, and location as covariates.

RESULTS

The most relevant histopathologic diagnosis of the index lesion was detected by the first biopsy core in 331 cases (73%), by the second in 66 cases (15%), and by the third in 39 cases (9%), by the fourth in 13 cases (3%), and by the fifth in two cases (<1%). The Bayes classifier correctly predicted which biopsy core yielded the most relevant histopathologic diagnosis in 79% of the subjects. PI-RADS score, PSA density, lesion size, zone, and location did not independently influence the prediction model.

CONCLUSION

The most relevant histopathologic diagnosis of the index lesion was made on the basis of three MRI-targeted biopsy cores in 97% of patients. Our classifier can help in predicting the first MRI-targeted biopsy core revealing the most relevant histopathologic diagnosis; however, at least three MRI-targeted biopsy cores should be obtained regardless of the preinterventionally assessed covariates.

Ultrasound/MRI-targeted biopsy versus saturated trans-rectal ultrasound guided biopsy of prostate in patients with primary negative conventional biopsy and still elevated PSA: a prospective randomized clinical trial

INTRODUCTION

To evaluate and compare the rate of cancer detection by two methods Saturated TRUS guided biopsy and ultrasound/magnetic resonance imaging (US/MRI)-targeted biopsy in patients with primary negative prostate cancer in standard 12 cores biopsy evaluation but still have elevated prostate specific antigen (PSA).

MATERIALS AND METHODS

From 105 patients who met our inclusion criteria, 53 patients underwent US/MRI-targeted biopsy and 52 remaining patients underwent Saturated 20 core TRUS guided biopsy in a prospective randomized clinical trial.

RESULTS

The mean age (±SD) was 62.2 (±8.2) year. The mean PSA (±SD) was 11.8 (±7.5) ng/ml. The mean prostate volume was 56.1 (±24.8) ml. Adenocarcinoma of prostate was detected in 9/52 (17.3%) patients in groups saturated biopsy and 14/53 (26.4%) patients in US/MRI-targeted biopsy group and there was no difference in cancer detection rate between 2 groups (P=0.252). except four patients with fever (two in each group), there was no other serious complication (Clavien grade 3 or higher) occurred in the patients. In the multivariate analysis, higher pre-procedure PSA, lower size of the prostate, pathology of ASAP and presence of nodule in DRE were independent predictors for cancer detection in second biopsy (P=0.036, P<0.001, P=0.013 and P=0.031, respectively).

CONCLUSION

We didn't find any superiority in cancer detection rate and any different in complication rate between these two methods saturated TRUS guided biopsy and US/MRI-targeted biopsy.

[Multiparametric MRI of the prostate: requirements and principles regarding diagnostic reporting]

Multiparametric MRI (mpMRI) is one of the primary diagnostic tools for detecting clinically relevant prostate cancer. It should be routinely used in addition to urological investigations owing to its higher diagnostic yield than systematic biopsies. However, combining targeted and systematic biopsies achieves the highest diagnostic rate. The Prostate Imaging Reporting and Data System (PI-RADS Version 2.1) standardizes the acquisition and interpretation of mpMRI of the prostate. It consists of high-resolution T2- and diffusion-weighted images, the corresponding apparent diffusion coefficient (ADC) maps, and a dynamic contrast-enhanced sequence. Reports describe the increasing likelihood of clinically significant prostate cancer with PI-RADS categories 1-5. The MRI sequence determining the PI-RADS category of a lesion depends on its location within the prostate: in the transitional zone, the T2-weighted sequence and, in the peripheral zone, the diffusion-weighted sequence are the primary determinants. The diffusion-weighted and contrast-enhanced sequences provide secondary classification for the transitional and peripheral zones, respectively. This review summarizes and illustrates the diagnostic criteria defined in PI-RADS 2.1. In addition, evidence for mpMRI of the prostate, its indication and implementation are described.

PSA change after antibiotic treatment should not affect decisionmaking on performing a prostate biopsy

BACKGROUND

To investigate the effect of antibiotic treatment on PSA when deciding on prostate biopsy.

METHODS

A total of 206 patients with an elevated PSA level (2.5-30) were included. Mp-MRI could be done on 129 patients. Patients were given ciprofloxacin (500 mg, b.i.d. p.o.) for 4 weeks and PSA measurements were repeated. Systematic prostate biopsy was performed regardless of PSA changes on all patients. Additionally, cognitive biopsies were performed from PI-RADs III, IV, and V lesions.

RESULTS

: Prostate cancer was detected in 36.4% of patients. 53.3% had Gleason score of 3+3, 46.7% had Gleason score ≥ 3+4. PSA values decreased in 56.3% and in 43.7% and remained the same or increased but cancer detection rates were not different: 34.5% vs. 38.9%, respectively (p = 0.514). PSA change in whole group was significant (6.38 ng/mL vs. 5.95 ng/mL, respectively (p = 0.01). No significant PSA decrease was observed in cancer patients (7.1 ng/mL vs. 7.05 ng/mL, p = 0.09), whereas PSA decrease was significant in patients with benign pathology (6.1 ng/mL vs. 5.5 ng/mL, p = 0.01). In patients with PI-RADs IV-V lesions, adenocarcinoma was present in 33.9% and 30.4% with or without PSA decrease, respectively (p = 0.209). Clinically significant cancer was higher in patients with after antibiotherapy PSA values >4 ng/mL regardless of PI-RADs grouping (p = 0.08). Addition of any PSA value to PI-RADs grouping did not have any significant effect on the detection of cancer.

DISCUSSION

PSA change after antibiotic treatment has no effect in detecting cancer and should not delay performing a biopsy.

Development and validation of 68Ga-PSMA-11 PET/CT-based radiomics model to detect primary prostate cancer

Background

This study aimed to develop a novel analytic approach based on a radiomics model derived from ⁶⁸Ga-prostate-specific membrane antigen (PSMA)-11 PET/CT for predicting intraprostatic lesions in patients with prostate cancer (PCa).

Methods

This retrospective study included consecutive patients with or without PCa who underwent surgery or biopsy after ⁶⁸Ga-PSMA-11 PET/CT. A total of 944 radiomics features were extracted from the images. A radiomics model was constructed using the least absolute shrinkage and selection operator (LASSO) algorithm with tenfold cross-validation in the training set. PET/CT images for the test set were reviewed by experienced nuclear medicine radiologists. The sensitivity, specificity, positive predictive value, negative predictive value, and area under the receiver operating characteristic curve (AUC) were calculated for the model and radiologists’ results. The AUCs were compared.

Results

The total of 125 patients (86 PCa, 39 benign prostate disease [BPD]) included 87 (61 PCa, 26 BPD) in the training set and 38 (61 PCa, 26 BPD) in the test set. Nine features were selected to construct the radiomics model. The model score differed between PCa and BPD in the training and test sets (both P < 0.001). In the test set, the radiomics model performed better than the radiologists’ assessment (AUC, 0.85 [95% confidence interval 0.73, 0.97] vs. 0.63 [0.47, 0.79]; P = 0.036) and showed higher sensitivity (model vs radiologists, 0.84 [0.63, 0.95] vs. 0.74 [0.53, 0.88]; P = 0.002).

Conclusion

Radiomics analysis based on ⁶⁸Ga-PSMA-11 PET may non-invasively predict intraprostatic lesions in patients with PCa.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13550-022-00936-5.

Diffusion-Weighted MRI in the Genitourinary System

Diffusion weighted imaging (DWI) constitutes a major functional parameter performed in Magnetic Resonance Imaging (MRI). The DW sequence is performed by acquiring a set of native images described by their b-values, each b-value representing the strength of the diffusion MR gradients specific to that sequence. By fitting the data with models describing the motion of water in tissue, an apparent diffusion coefficient (ADC) map is built and allows the assessment of water mobility inside the tissue. The high cellularity of tumors restricts the water diffusion and decreases the value of ADC within tumors, which makes them appear hypointense on ADC maps. The role of this sequence now largely exceeds its first clinical apparitions in neuroimaging, whereby the method helped diagnose the early phases of cerebral ischemic stroke. The applications extend to whole-body imaging for both neoplastic and non-neoplastic diseases. This review emphasizes the integration of DWI in the genitourinary system imaging by outlining the sequence's usage in female pelvis, prostate, bladder, penis, testis and kidney MRI. In gynecologic imaging, DWI is an essential sequence for the characterization of cervix tumors and endometrial carcinomas, as well as to differentiate between leiomyosarcoma and benign leiomyoma of the uterus. In ovarian epithelial neoplasms, DWI provides key information for the characterization of solid components in heterogeneous complex ovarian masses. In prostate imaging, DWI became an essential part of multi-parametric Magnetic Resonance Imaging (mpMRI) to detect prostate cancer. The Prostate Imaging-Reporting and Data System (PI-RADS) scoring the probability of significant prostate tumors has significantly contributed to this success. Its contribution has established mpMRI as a mandatory examination for the planning of prostate biopsies and radical prostatectomy. Following a similar approach, DWI was included in multiparametric protocols for the bladder and the testis. In renal imaging, DWI is not able to robustly differentiate between malignant and benign renal tumors but may be helpful to characterize tumor subtypes, including clear-cell and non-clear-cell renal carcinomas or low-fat angiomyolipomas. One of the most promising developments of renal DWI is the estimation of renal fibrosis in chronic kidney disease (CKD) patients. In conclusion, DWI constitutes a major advancement in genitourinary imaging with a central role in decision algorithms in the female pelvis and prostate cancer, now allowing promising applications in renal imaging or in the bladder and testicular mpMRI.

Image-guided in-Vivo Needle-Based Confocal Laser Endomicroscopy in the Prostate: Safety and Feasibility Study in 2 Patients

Purpose: To assess the safety and technical feasibility of in-vivo needle-based forward-looking confocal laser endomicroscopy in prostate tissue. Methods: For this feasibility study, 2 patients with a suspicion of prostate cancer underwent transperineal needle-based confocal laser endomicroscopy during ultrasound-guided transperineal template mapping biopsies. After intravenous administration of fluorescein, needle-based confocal laser endomicroscopy imaging was performed with a forward-looking probe (outer diameter 0.9 mm) in 2 trajectories during a manual push-forward and pullback motion. A biopsy was taken in a coregistered parallel adjacent trajectory to the confocal laser endomicroscopy trajectory for histopathologic comparison. Peri- and postprocedural adverse events, confocal laser endomicroscopy device malfunction and procedural failures were recorded. Needle-based confocal laser endomicroscopy image quality assessment, image interpretation, and histology were performed by an experienced confocal laser endomicroscopy rater and uro-pathologist, blinded to any additional information. Results: In both patients, no peri- and post-procedural adverse events were reported following needle-based confocal laser endomicroscopy. No confocal laser endomicroscopy device malfunction nor procedural failures were reported. Within 1.5 min after intravenous administration of fluorescein, needle-based confocal laser endomicroscopy image quality was sufficient for interpretation for at least 14 min, yielding more than 5000 confocal laser endomicroscopy frames per patient. The pullback confocal laser endomicroscopy recordings and most of the push-forward recordings almost only visualized erythrocytes, being classified as non-representative. During the push-forward recordings, prostate tissue was occasionally visualized in single frames, insufficient for histopathologic comparison. Prostate carcinoma was identified by biopsy in one patient (Gleason score 4 + 3 = 7, >50%), while the biopsy from the other patient showed no malignancy. Conclusion: Needle-based confocal laser endomicroscopy imaging of in-vivo prostate tissue with a forward-looking confocal laser endomicroscopy probe is safe without device malfunctions or procedural failures. Needle-based confocal laser endomicroscopy is technically feasible, but the acquired confocal laser endomicroscopy datasets are non-representative. The confocal laser endomicroscopy images’ non-representative nature is possibly caused by bleeding artifacts, movement artifacts and a lack of contact time with the tissue of interest. A different confocal laser endomicroscopy probe or procedure might yield representative images of prostatic tissue.

Additional Value of PET Radiomic Features for the Initial Staging of Prostate Cancer: A Systematic Review from the Literature

Simple Summary

Prostate cancer (PCa) is one of the most frequent malignancies diagnosed in men and its prognosis depends on the stage at diagnosis. Molecular imaging, namely PET/CT or PET/MRI using prostate-specific radiotracers, has gained increasing application in accurately evaluating PCa at staging, especially in cases of high-risk disease, and it is now also recommended by international guidelines. Radiomic analysis is an emerging research field with a high potential to offer non-invasive and longitudinal biomarkers for personalized medicine, and several applications have been described in oncology patients. In this review, we discuss the available evidence on the role of radiomic analysis in PCa imaging at staging, exploring two different hybrid imaging modalities, such as PET/CT and PET/MRI, and the whole spectrum of radiotracers involved.

Abstract

We performed a systematic review of the literature to provide an overview of the application of PET radiomics for the prediction of the initial staging of prostate cancer (PCa), and to discuss the additional value of radiomic features over clinical data. The most relevant databases and web sources were interrogated by using the query “prostate AND radiomic* AND PET”. English-language original articles published before July 2021 were considered. A total of 28 studies were screened for eligibility and 6 of them met the inclusion criteria and were, therefore, included for further analysis. All studies were based on human patients. The average number of patients included in the studies was 72 (range 52–101), and the average number of high-order features calculated per study was 167 (range 50–480). The radiotracers used were [68Ga]Ga-PSMA-11 (in four out of six studies), [18F]DCFPyL (one out of six studies), and [11C]Choline (one out of six studies). Considering the imaging modality, three out of six studies used a PET/CT scanner and the other half a PET/MRI tomograph. Heterogeneous results were reported regarding radiomic methods (e.g., segmentation modality) and considered features. The studies reported several predictive markers including first-, second-, and high-order features, such as “kurtosis”, “grey-level uniformity”, and “HLL wavelet mean”, respectively, as well as PET-based metabolic parameters. The strengths and weaknesses of PET radiomics in this setting of disease will be largely discussed and a critical analysis of the available data will be reported. In our review, radiomic analysis proved to add useful information for lesion detection and the prediction of tumor grading of prostatic lesions, even when they were missed at visual qualitative assessment due to their small size; furthermore, PET radiomics could play a synergistic role with the mpMRI radiomic features in lesion evaluation. The most common limitations of the studies were the small sample size, retrospective design, lack of validation on external datasets, and unavailability of univocal cut-off values for the selected radiomic features.

Effectiveness of magnetic resonance imaging-targeted biopsy for detection of prostate cancer in comparison with systematic biopsy in our countries with low prevalence of prostate cancer: our first experience after 3 years

Background

Some men are subjected to multiple repeated biopsies because of ongoing suspicion of prostate cancer, which might subject them to complications. The aim of the study was to determine the diagnostic accuracy of magnetic resonance imaging (MRI)/target fusion-guided biopsy in comparison with systematic biopsy in our low prevalence prostate cancer population, in terms of validity measure, case detection rate, and detection of clinically significant cancer.

Methods

This is a retrospective cohort study. All consecutive patients who met the inclusion criteria (all men with persistent high prostate-specific antigen levels >4 ng/ml and/or subnormal finding in direct rectal examination, with suspicious regions identified on prebiopsy MRI) were subjected to transrectal MRI/ultrasound fusion-guided biopsy.

Results

A total of 165 cases met the inclusion criteria and were included in the study. The cancer detection rate (CDR) of target biopsy was significantly higher than that of standard biopsy (27.9% vs 14%, respectively), and 25 cases (52%) were missed by standard strategy and correctly classified by multiparametric MRI with targeted biopsy (MRI-TB). On the other hand, only 2 cases (4.3%) were misclassified by MRI-TB, and one of them was clinically significant. There was an exact agreement between the 2 strategies in 15 (31%) cases. Targeted biopsy diagnosed 41.5% more high-risk cancers vs systematic biopsy (41.6% vs 6.2%, P < .001). The difference between sensitivity, specificity, and negative predictive value of MRI-TG varies between 80% and 98%.

Conclusion

The CDR of prostate cancer in general and clinically significant cancer, in specific, is significantly higher with MRI-TG modality than with systematic modality. Yet, MRI-TG biopsy still misses some men with clinically significant prostate cancer. Hence, the addition of a 12-core biopsy is required to evade missing cases of clinically significant and insignificant cancer.

Initial experience with a novel method for cognitive transperineal magnetic resonance imaging-targeted prostate biopsy

A cognitive magnetic resonance imaging (MRI)-targeted prostate biopsy conducted by an experienced clinician enhances the detection rate of (high-grade) prostate cancer; however, this method is less successful in the hands of inexperienced surgeons. Therefore, an alternative method of conducting a cognitive MRI-targeted biopsy that can be successfully performed by the inexperienced clinicians should be developed. Ninety-six males suspected of prostate cancer were analyzed using systematic biopsy and cognitive MRI-targeted biopsy based on our novel three-dimensional matrix positioning method. Typically, the core principle of the latter procedure was to put the MRI and ultrasound images into the same virtual coordinate system. Afterward, the targeted biopsy was transformed to target a coordinate for the suspected lesion in the MRI. Subsequently, patients were assessed for the presence/absence of prostate cancer or high-grade prostate cancer. According to our results, the overall detection rate of prostate cancer was 70.8% (68/96), and the detection rate of high-grade prostate cancer was 56.3% (54/96). Specifically, the detection rate of prostate cancer by systematic biopsy was 54.2% (52/96) and that by targeted biopsy was 59.4% (57/96; P = 0.560). Clearly, the combined application of targeted biopsy could remarkably increase the detection rates of prostate cancer (P = 0.025) and high-grade prostate cancer (P = 0.009). Taken together, the findings of this study suggest that the combination of systematic biopsy with our three-dimensional matrix positioning-driven cognitive-targeted biopsy is superior to systematic biopsy in detecting prostate cancer and high-grade prostate cancer.

Systematic and MRI-Cognitive Targeted Transperineal Prostate Biopsy Accuracy in Detecting Clinically Significant Prostate Cancer after Previous Negative Biopsy and Persisting Suspicion of Malignancy

Background and objectives: Overdiagnosis, overtreatment, and the need for repeated procedures caused by transrectal ultrasound guided prostate biopsies and their related complications places a heavy burden on healthcare systems. This was a prospective cohort validating study to access the clinical accuracy of systematic and MRI-cognitive targeted transperineal prostate biopsies in detecting clinically significant prostate cancer after a previous negative biopsy and persistent suspicion of malignancy. The primary goal was to assess the ability of multiparametric magnetic resonance imaging (mpMRI) to detect clinically significant prostate cancer with an additional goal to assess the diagnostic value of systematic and MRI-cognitive transperineal biopsies. Materials and Methods: In total, 200 patients were enrolled who had rising serum prostate specific antigen (PSA) levels for at least 4 months after a previous negative transrectal ultrasound (TRUS) biopsy. All eligible men underwent 1.5T prostate mpMRI, reported using the Prostate Imaging Reporting and Data System version 2 (PI-RADS v2), followed by a 20-region transperineal prostate systematic biopsy and additional targeted biopsies. Results: Systematic 20-core transperineal prostate biopsies (TPBs) were performed for 38 (19%) patients. Systemic 20-core TPB with additional cognitive targeted biopsies were performed for 162 (81%) patients. Clinically significant prostate cancer (csPC) was detected for 31 (15.5%) patients, of which 20 (64.5%) cases of csPC were detected by systematic biopsy, eight (25.8%) cases were detected by targeted biopsy, and three (9.7%) both by systematic and targeted biopsies. Conclusions: Cognitive mpMRI guided transperineal target biopsies increase the detection rate of clinically significant prostate cancer after a previously negative biopsy. However, in a repeat prostate biopsy setting, we recommend applying a cognitive targeted biopsy with the addition of a systematic biopsy.

Characterisation of Prostate Lesions Using Transrectal Shear Wave Elastography (SWE) Ultrasound Imaging: A Systematic Review

BACKGROUND

ultrasound-based shear wave elastography (SWE) can non-invasively assess prostate tissue stiffness. This systematic review aims to evaluate SWE for the detection of prostate cancer (PCa) and compare diagnostic estimates between studies reporting the detection of all PCa and clinically significant PCa (csPCa).

METHODS

a literature search was performed using the MEDLINE, EMBASE, Cochrane Library, ClinicalTrials.gov, and CINAHL databases. Studies evaluating SWE for the detection of PCa using histopathology as reference standard were included.

RESULTS

16 studies including 2277 patients were included for review. Nine studies evaluated SWE for the detection of PCa using systematic biopsy as a reference standard at the per-sample level, with a pooled sensitivity and specificity of 0.85 (95% CI = 0.74-0.92) and 0.85 (95% CI = 0.75-0.91), respectively. Five studies evaluated SWE for the detection of PCa using histopathology of radical prostatectomy (RP) specimens as the reference standard, with a pooled sensitivity and specificity of 0.71 (95% CI = 0.55-0.83) and 0.74 (95% CI = 0.42-0.92), respectively. Sub-group analysis revealed a higher pooled sensitivity (0.77 vs. 0.62) and specificity (0.84 vs. 0.53) for detection of csPCa compared to all PCa among studies using RP specimens as the reference standard.

CONCLUSION

SWE is an attractive imaging modality for the detection of PCa.

Low reduction of prostate volume is a significant predictor of prostate cancer at subsequent biopsy in patients with dutasteride: A retrospective study

Appropriate decision of prostate biopsy in men with 5α‐reductase inhibitor (5AR inhibitor) is still unclear to avoid unnecessary biopsy. We retrospectively investigated patients with initial PSA 4.0 ng/ml or more and underwent subsequent prostate biopsy following dutasteride treatment. From September 2009 to August 2018, 399 cases of benign prostate hyperplasia (BPH) were treated with dutasteride in our department. Of the total, 36 cases with elevated pre‐treatment PSA (4.0 ng/ml or more) and underwent subsequent prostate biopsy were included into this study. We evaluated PSA kinetics and changing prostate volumes (PV), and detection of prostate cancer. Overall, average PSA reduced by half at 6 months from dosing. Pre‐treatment biopsy was performed in 17 of 36 cases, and all were diagnosed as having no malignancy. After treatment, prostate cancer was detected in 15 cases by subsequent biopsy. Fourteen of 15 cases were clinically significant cancer (Gleason score 7 or more). Logistic regression analysis detected a nominal association between prostate cancer detection and three variants, PSAD, PV reduction (1–Before/After PV) and abnormal MRI findings. In addition to abnormal MRI findings and pre‐treatment of high PSAD, the case with low reduction of PV after treatment should consider performing prostate biopsy.

A novel tetrapeptide fluorescence sensor for early diagnosis of prostate cancer based on imaging Zn2+ in healthy versus cancerous cells

Zinc as a biomarker can be used to diagnose the early stage prostate cancer, while ZIP1 protein, a zinc transporter is significantly down-regulated in prostate cancer cells. This behavior leads to the apparent alteration of the enrichment ability for zinc between early prostate cancer tissues and healthy tissues. This difference inspires us to develop a novel Zn²⁺ sensor that applies to the clinic diagnosis of early prostate cancer. We designed a tetrapeptide sensor H₂L (Dansyl-Gly-Pro-Trp-Gly-NH₂) according to the photo-induced electron transfer principle (PET), and it performed adequately in Zn²⁺ imaging of prostate cell lines. Based on the assessment of Zn²⁺ enrichment ability, there was distinctly lower Zn²⁺ concentrate in prostate cancer cell lines than healthy prostate epithelial cells. Furthermore, H₂L displayed high sensitivity with a detection limit as low as 49.5 nM, and high specificity for Zn²⁺ detection. Also the low toxicity and the superior cell permeability of H₂L made the imaging of Zn²⁺ ions detection safe and rapid. We expect that H₂L to be a powerful tool for early diagnosis of prostate cancer and a good indicator for the precise resection of cancer tissue during surgery.

Active Surveillance of Prostate Cancer Using Multiparametric Magnetic Resonance Imaging: A Review of the Current Role and Future Perspectives

Clinically, active surveillance involves continuous monitoring of patients who may be at risk for disease. Patients with low-grade and early-stage prostate cancer may benefit from active surveillance, rather than undergoing surgical and medical treatments that are associated with side effects. In these cases, the role of active surveillance is to ensure that there is no progression of the disease. However, active surveillance may be associated with a risk of under-diagnosis. Previously, the assignment of risk categories and patient monitoring were based on digital rectal examination, transrectal prostate biopsy, and monitoring of serum levels of prostate-specific antigen (PSA). Multiparametric magnetic resonance imaging (MRI) of the prostate gland has an estimated negative predictive value of 95% for the detection of prostate cancer, which makes this an effective imaging method for targeting biopsies and for monitoring patients over time. Also, multiparametric MRI-guided biopsy at the initial stage of the risk stratification for patients who are newly diagnosed with prostate cancer may reduce the number of underdiagnosed patients, improve long-term patient prognosis, and reduce the number of patients who are overtreated, which may reduce healthcare costs and reduce treatment morbidity. For these reasons, multiparametric MRI has become an accepted monitoring tool in patients who are enrolled in active surveillance programs. This review aims to present the current status of the use of multiparametric MRI in active surveillance of prostate cancer and to discuss future perspectives, supported by recent literature.

Quantifying the effect of biopsy lateral decubitus patient positioning compared to supine prostate magnetic resonance image scanning on prostate translocation and distortion

INTRODUCTION

More than a quarter of tumors are missed by magnetic resonance imaging/ultrasound (MRI/US) fusion-guided biopsy, the majority due to software-based misregistration. Transrectal approaches to biopsy are typically performed in the lateral decubitus position; conversely, diagnostic MRI is performed with the patient lying supine. Any position-related difference in prostate location or gland deformation could potentially exacerbate misregistration at subsequent biopsy.

METHODS

Fifteen healthy male volunteers (mean age 35.9 years, range 27-53) were included in this prospective, institutional review board-approved study. Each volunteer had an MRI performed in the supine position, followed by the second in the lateral decubitus position (mimicking a typical biopsy position). MRI images were co-registered and analyzed in order to assess prostate translocation and distortion.

RESULTS

Whole prostate translocation of ≥5 mm was observed in 20% of patients and of ≥3 mm in 60% of patients. When dividing the prostate into prostatic sectors, the prostatic base demonstrated the largest positional difference. When plotting the translocation directions with relative volume difference, there was a moderate negative correlation trend in the latero-lateral direction. Only minimal distortion was observed, with similar distortion among all prostatic sectors.

CONCLUSIONS

Positional change affects the prostate translocation, however, the effect on prostate distortion appears to be negligible. Prostate translocation in latero-lateral direction can be minimized with larger bladder volumes. Prostate translocation needs to be considered alongside software misregistration error; however, positional change should not affect software registration of MRI/US fusion-guided prostate biopsy.

Is Holmium Laser Enucleation of the Prostate a Good Surgical Alternative in Benign Prostatic Hyperplasia Management? A Review Article

Several therapeutic approaches such as holmium laser enucleation of the prostate (HoLEP) have been introduced to relieve bladder outlet obstruction caused by benign prostatic hyperplasia (BPH). Compared with other techniques including the transurethral resection of the prostate (TURP) and simple open prostatectomy, HoLEP results in a shorter hospital stay and catheterization time and fewer blood loss and transfusions. HoLEP is a size-independent treatment option for BPH with average gland size from 36 g to 170 g. HoLEP is a safe procedure in patients receiving an anticoagulant and has no significant influence on the hemoglobin level. Also, HoLEP is an easy and safe technique in patients with a prior history of prostate surgery and a need for retreatment because of adenoma regrowth. The postoperative erectile dysfunction rate of patients treated with HoLEP is similar to TURP or open prostatectomy and about 77% of these patients experience loss of ejaculation. Patients with transitional zone volume less than 30 mL may suffer from persistent stress urinary incontinence following HoLEP so other surgical techniques like bipolar TURP are a good choice for these patients. In young patients, considering HoLEP with high prostate-specific antigen density and a negative standard template prostate biopsy, multiparametric MRI needs to be considered to exclude prostate cancer.

Gleason Probability Maps: A Radiomics Tool for Mapping Prostate Cancer Likelihood in MRI Space

Prostate cancer is the most common noncutaneous cancer in men in the United States. The current paradigm for screening and diagnosis is imperfect, with relatively low specificity, high cost, and high morbidity. This study aims to generate new image contrasts by learning a distribution of unique image signatures associated with prostate cancer. In total, 48 patients were prospectively recruited for this institutional review board–approved study. Patients underwent multiparametric magnetic resonance imaging 2 weeks before surgery. Postsurgical tissues were annotated by a pathologist and aligned to the in vivo imaging. Radiomic profiles were generated by linearly combining 4 image contrasts (T2, apparent diffusion coefficient [ADC] 0-1000, ADC 50-2000, and dynamic contrast-enhanced) segmented using global thresholds. The distribution of radiomic profiles in high-grade cancer, low-grade cancer, and normal tissues was recorded, and the generated probability values were applied to a naive test set. The resulting Gleason probability maps were stable regardless of training cohort, functioned independent of prostate zone, and outperformed conventional clinical imaging (area under the curve [AUC] = 0.79). Extensive overlap was seen in the most common image signatures associated with high- and low-grade cancer, indicating that low- and high-grade tumors present similarly on conventional imaging.

Differentiating Cancerous and Non-cancerous Prostate Tissue Using Multi-scale Texture Analysis on MRI

Prostate cancer (PCa) diagnosis is established by pathological examination via biopsies, which are associated with significant complications and false negatives. Using MRIs to identify locations with high probability of containing cancer could instead be used to guide the biopsy procedure. The present investigation aims to identify target regions within different prostatic zones on MRI with high probability of being cancerous for assisting in the decision of where and how to perform biopsy. Our approach involved extracting multi-scale texture features for capturing local patterns to distinguish cancer and healthy tissue in different T2W-MRI prostate zones. Three different classification models were fed by the proposed strategy, namely support vector machine (SVM), Adaboost, and Random Forest. SVM with a linear kernel showed the best classification performance, with AUC scores of 0.91 in the anterior fibromuscular stroma area, 0.85 in the peripheral zone, and 0.87 when classification is performed independently of the prostate zone. The proposed method demonstrated that discriminant multi-scale texture features can accurately identify regions of prostate cancer in a zone-specific fashion, via MRI.

Multiparametric MRI for prostate cancer diagnosis: current status and future directions

The current diagnostic pathway for prostate cancer has resulted in overdiagnosis and consequent overtreatment as well as underdiagnosis and missed diagnoses in many men. Multiparametric MRI (mpMRI) of the prostate has been identified as a test that could mitigate these diagnostic errors. The performance of mpMRI can vary depending on the population being studied, the execution of the MRI itself, the experience of the radiologist, whether additional biomarkers are considered and whether mpMRI-targeted biopsy is carried out alone or in addition to systematic biopsy. A number of challenges to implementation remain, such as ensuring high-quality execution and reporting of mpMRI and ensuring that this diagnostic pathway is cost-effective. Nevertheless, emerging clinical trial data support the adoption of this technology as part of the standard of care for the diagnosis of prostate cancer.

Personalized Risks of Over Diagnosis for Screen Detected Prostate Cancer Incorporating Patient Comorbidities: Estimation and Communication

PURPOSE

Shared patient-physician decision making regarding the treatment of prostate cancer detected by prostate specific antigen screening involves a complex calculus weighing cancer risk and patient life expectancy. We sought to quantify these competing risks using the probability that the cancer was over diagnosed, ie would not have been clinically diagnosed (diagnosed without screening) during the remaining lifetime of the patient.

MATERIALS AND METHODS

Using an established model of prostate cancer screening and clinical diagnosis we simulated screen detected cases and determined whether a modeled clinical diagnosis would occur before noncancer death. Time of noncancer death was based on comorbidity adjusted population lifetables. Logistic regression models were fitted to the simulated data and used to estimate over diagnosis probabilities given patient age, prostate specific antigen level, Gleason sum and comorbidity category. An online calculator was developed to communicate over diagnosis estimates. Face validity and ease of use were assessed by surveying 32 clinical experts.

RESULTS

Estimated probabilities of over diagnosis ranged from 4% to 78% across clinicopathological variables and comorbidity status. When ignoring comorbidity, the estimated probability of over diagnosis in a 70-year-old man with prostate specific antigen 9.4 ng/ml and Gleason 6 was 34%. With severe comorbidities the estimate increased to 51%. Such a personalization may help inform the choice between active surveillance and definitive treatment. Based on responses from 20 of 32 experts we modified the explanation of over diagnosis for the online calculator and the input method for comorbid conditions.

CONCLUSIONS

The probability of over diagnosis is strongly influenced by comorbidity status in addition to age. Personalized estimates incorporating comorbidity may contribute to shared decision making between patients and providers regarding personalized treatment selection.

Photoacoustic imaging of clofazimine hydrochloride nanoparticle accumulation in cancerous vs normal prostates

Prostate cancer was the most common form and had the second highest death rate of male cancer in the United States in 2015. Current diagnosis techniques, such as prostate-specific antigen tests, transrectal ultrasound scans, and biopsies, are often inconclusive, and in the latter case, invasive. Here, we explore the use of clofazimine hydrochloride nanoparticles (CFZ-HCl NPs), a repurposed formulation from an FDA-approved antimycobacterial agent, as a photoacoustic contrast agent for the evaluation of prostate cancer due to its macrophage-targeting capabilities and high optical absorbance at 495 nm. Using a transgenic adenocarcinoma of the mouse prostate (TRAMP) mouse model, our results indicate a preferential accumulation of intravenously injected CFZ-HCl NPs in cancerous prostates over normal prostates. Differences in accumulation of CFZ-HCl NPs between cancerous and normal prostates were determined using a two-wavelength unmixing technique via ex vivo photoacoustic imaging. Thus, intravenous injection of CFZ-HCl NPs leads to differences in the interactions of the particles with cancerous vs normal prostates, while allowing for photoacoustic detection and analysis of prostate cancer. These findings could lead to the development of a new noninvasive technique for the detection and monitoring of prostate cancer progression in an animal model that can potentially be translated to human patients.

The First In Vivo Needle-Based Optical Coherence Tomography in Human Prostate: A Safety and Feasibility Study

OBJECTIVE

To demonstrate the safety and feasibility of clinical in vivo needle-based optical coherence tomography (OCT) imaging of the prostate.

MATERIALS AND METHODS

Two patients with prostate cancer underwent each two percutaneous in vivo needle-based OCT measurements before transperineal template mapping biopsy. The OCT probe was introduced via a needle and positioned under ultrasound guidance. To test the safety, adverse events were recorded during and after the procedure. To test the feasibility, OCT and US images were studied during and after the procedure. Corresponding regions for OCT and biopsy were determined. A uropathologist evaluated and annotated the histopathology. Three experts assessed all the corresponding OCT images. The OCT and biopsy conclusions for the corresponding regions were compared.

RESULTS

No adverse events during and following the, in total four, in vivo needle-based OCT measurements were reported. The OCT measurements showed images of prostatic tissue with a penetration depth of ~1.5 mm. The histological-proven tissue types, which were also found in the overlapping OCT images, were benign glands, stroma, glandular atrophy, and adenocarcinoma (Gleason pattern 3).

CONCLUSIONS

Clinical in vivo needle-based OCT of the prostate is feasible with no adverse events during measurements. OCT images displayed detailed prostatic tissue with a imaging depth up to ~1.5 mm. We could co-register four histological-proven tissue types with OCT images. The feasibility of in vivo OCT in the prostate opens the pathway to the next phase of needle-based OCT studies in the prostate. Lasers Surg. Med. 51:390-398, 2019. © 2019 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc.

Preoperative multiparametric prostate magnetic resonance imaging: a safe clinical practice to reduce incidental prostate cancer in Holmium laser enucleation of the prostate

Introduction

Purpose of the study was to investigate the correlation of a preoperative multiparametric magnetic resonance imaging of the prostate (mpMRI) in patients with a suspicion of prostate cancer and eligible for Holmium Laser Enucleation of the Prostate (HoLEP).

Material and methods

Data of 228 patients who had undergone HoLEP was selected and retrospectively analyzed from a multicentric database. All patients presented with a raised serum PSA and/or an abnormal digital rectal examination (DRE). Prostate cancer (PCa) was excluded either with a negative mpMRI (group ‘NEGATIVE MRI’ n = 113) or a standard biopsy (group ‘NO MRI’ n = 115). Preoperative characteristic surgical and histological outcomes were confronted. A univariate and multivariate logistic regression model was performed to investigate independent predictors of incidental Prostate Cancer (iPCa).

Results

Both groups presented with no statistical differences in preoperative characteristics besides previous acute urinary retention rates and post-voided residual volume, found to be higher (27.8% vs. 14.2% and median 120cc vs. 80cc) in NO MRI and NEGATIVE MRI respectively.

No differences were registered in surgical time, removed tissue, catheterization time, hospital stay and complications rate.

Statistically lower rate of iPCa (p = 0.03) was detected in the NEGATIVE MRI group (6.2%) in comparison with NO MRI group (14.8%). In multivariate logistic regression only presence of a preoperative negative mpMRI correlated (p = 0.04) as an independent predictive factor (OR 2.63; 95% CI: 1.02–6.75).

Conclusions

A negative mpMRI might be a useful tool to be included in a novel preoperative assessment to patients eligible for HoLEP with a suspicion of PCa in order to avoid an incidental PCa.

Molecular Pathology of High-Grade Prostatic Intraepithelial Neoplasia: Challenges and Opportunities

A better understanding of the early stages of prostate cancer initiation, potentially arising from precursor lesions, may fuel development of powerful approaches for prostate cancer prevention or interception. The best-known candidate for such a precursor lesion has been referred to as high-grade prostatic intraepithelial neoplasia (HGPIN). Although there is significant evidence supporting the notion that such HGPIN lesions can give rise to invasive adenocarcinomas of the prostate, there are also numerous complicating considerations and evidence that cloud the picture in many instances. Notably, recent evidence has suggested that some fraction of such lesions that are morphologically consistent with HGPIN may actually be invasive carcinomas masquerading as HGPIN-a state that we term "postinvasive intraepithelial carcinoma" (PIC). Although the prevalence of such PIC lesions is not fully understood, this and other factors can confound the potential of identifying prostate precursors that can be targeted for disease prevention, interception, or treatment. Here, we review our current understanding of the morphological and molecular pathological features of prostate cancer precursor lesions.

Literature review of the burden of prostate cancer in Germany, France, the United Kingdom and Canada

BACKGROUND

Prostate cancer is the most frequently reported cancer in males in Europe, and is associated with substantial morbidity and mortality. The aim of the current review was to characterize the clinical, economic and humanistic burden of disease associated with prostate cancer in France, Germany, the UK and Canada.

METHODS

Literature searches were conducted using the PubMed, EMBASE and Cochrane Library databases to identify studies reporting incidence and/or mortality rates, costs and health state utilities associated with prostate cancer in the settings of interest. For inclusion, studies were required to be published in English in full-text form from 2006 onwards.

RESULTS

Incidence studies showed that in all settings the incidence of prostate cancer has increased substantially over the past two decades, driven in part by increased uptake of prostate specific antigen (PSA) screening leading to earlier identification of tumors, but which has also led to over-treatment, compounding the economic burden of disease. Mortality rates have declined over the same time frame, driven by earlier detection and improvements in treatment. Both prostate cancer itself, as well as treatment and treatment-related complications, are associated with reduced quality of life.

CONCLUSIONS

Prostate cancer is associated with a significant clinical and economic burden, whilst earlier detection and aggressive treatment is associated with improved survival, over-treatment of men with indolent tumors compounds the already significant burden of disease and treatment can lead to long-term side effects including impotence and impaired urinary and/or bowel function. There is currently an unmet clinical need for diagnostic and/or prognostic tools that facilitate personalized prostate cancer treatment, and potentially reduce the clinical, economic and humanistic burden of invasive cancer treatment.

Does the prostate volume always effect cancer detection rate in prostate biopsy? Additional role of prostate-specific antigen levels: A retrospective analysis of 2079 patients

OBJECTIVE

We aimed to determine whether the effect of prostate volume on cancer detection rates is influenced by serum prostate-specific antigen (PSA).

MATERIAL AND METHODS

A total of 2465 men who underwent transrectal ultrasound-guided biopsy were retrospectively evaluated. Standard 10-core prostate biopsy was performed in all cases. Patients were divided into three groups according to the serum PSA levels: ≤10 ng/mL (Group 1), 10-20 ng/mL (Group 2) and >20 ng/mL (Group 3). In each group age, serum PSA levels and prostate volumes were compared in patients with and without prostate cancer.

RESULTS

A total of 2079 patients were included in the study group. Cancer detection rates were 16%, 25%, 53% in Groups 1, 2 and 3, respectively (p=0.001). In Group 1, there was a significant difference in mean prostate volume of patients with and without prostate cancer (p=0.01). However, this difference was not seen in Group 2 or 3 (p=0.06 and p=0.08, respectively). The mean age and PSA level which are the other determinants of prostate cancer diagnosis were similar between patients with and without cancer in the Group 1, thus prostate volume was the only determinant of the diagnosis.

CONCLUSION

According to our findings, prostate volume is an important factor for prostate cancer diagnosed with prostate biopsy only in patients with a PSA level of ≤10 ng/mL.

Genomic Evaluation of Multiparametric Magnetic Resonance Imaging-visible and -nonvisible Lesions in Clinically Localised Prostate Cancer

BACKGROUND

The prostate cancer (PCa) diagnostic pathway is undergoing a radical change with the introduction of multiparametric magnetic resonance imaging (mpMRI), genomic testing, and different prostate biopsy techniques. It has been proposed that these tests should be used in a sequential manner to optimise risk stratification.

OBJECTIVE

To characterise the genomic, epigenomic, and transcriptomic features of mpMRI-visible and -nonvisible PCa in clinically localised disease.

DESIGN, SETTING, AND PARTICIPANTS

Multicore analysis of fresh prostate tissue sampled immediately after radical prostatectomy was performed for intermediate- to high-risk PCa.

INTERVENTION

Low-pass whole-genome, exome, methylation, and transcriptome profiling of patient tissue cores taken from microscopically benign and cancerous areas in the same prostate. Circulating free and germline DNA was assessed from the blood of five patients.

OUTCOME MEASUREMENT AND STATISTICAL ANALYSIS

Correlations between preoperative mpMRI and genomic characteristics of tumour and benign prostate samples were assessed. Gene profiles for individual tumour cores were correlated with existing genomic classifiers currently used for prognostication.

RESULTS AND LIMITATIONS

A total of 43 prostate cores (22 tumour and 21 benign) were profiled from six whole prostate glands. Of the 22 tumour cores, 16 were tumours visible and six were tumours nonvisible on mpMRI. Intratumour genomic, epigenomic, and transcriptomic heterogeneity was found within mpMRI-visible lesions. This could potentially lead to misclassification of patients using signatures based on copy number or RNA expression. Moreover, three of the six cores obtained from mpMRI-nonvisible tumours harboured one or more genetic alterations commonly observed in metastatic castration-resistant PCa. No circulating free DNA alterations were found. Limitations include the small cohort size and lack of follow-up.

CONCLUSIONS

Our study supports the continued use of systematic prostate sampling in addition to mpMRI, as avoidance of systematic biopsies in patients with negative mpMRI may mean that clinically significant tumours harbouring genetic alterations commonly seen in metastatic PCa are missed. Furthermore, there is inconsistency in individual genomics when genomic classifiers are applied.

PATIENT SUMMARY

Our study shows that tumour heterogeneity within prostate tumours visible on multiparametric magnetic resonance imaging (mpMRI) can lead to misclassification of patients if only one core is used for genomic analysis. In addition, some cancers that were missed by mpMRI had genomic aberrations that are commonly seen in advanced metastatic prostate cancer. Avoiding biopsies in mpMRI-negative cases may mean that such potentially lethal cancers are missed.

Multiparametric MRI Features and Pathologic Outcome of Wedge-Shaped Lesions in the Peripheral Zone on T2-Weighted Images of the Prostate

OBJECTIVE

This study investigates the multiparametric MRI (mpMRI) characteristics and pathologic outcome of wedge-shaped lesions observed on T2-weighted images.

MATERIALS AND METHODS

Seventy-six patients with histologically confirmed prostate cancer underwent preoperative 3-T MRI before undergoing radical prostatectomy. Two radiologists worked in consensus to mark wedge-shaped regions of hypointensity on T2-weighted images and assess their appearance on apparent diffusion coefficient (ADC) maps (to determine the degree of hypointensity) and dynamic contrast-enhanced (DCE) MRI (DCE-MRI) (to assess whether they showed early enhancement). The pathologic outcome of wedge-shaped lesions was assessed by matching MR images with whole-mount histologic specimens retrospectively. The difference in quantitative ADC values between malignant and benign wedge-shaped lesions was assessed using a t test.

RESULTS

Thirty-five wedge-shaped regions were identified, 12 (34%) of which were found be malignant. Most malignant wedge-shaped regions were highly hypointense (10/12; 83%) on ADC maps and showed early enhancement on DCE-MRI (7/12; 58%). However, benign wedge-shaped lesions were predominantly mildly hypointense (13/23; 57%) on ADC maps and showed no early enhancement (15/23; 65%). Histologic correlates of the benign wedge-shaped regions showed prostatitis (acute inflammation [7/23; 30%] or chronic inflammation [9/23; 39%]), hemosiderin-laden macrophages (6/23; 26%), prominent blood vessels (7/23; 30%), intraluminal blood (6/23; 26%), and nonspecific atrophy (6/23; 26%). The mean (± SD) quantitative ADC value of malignant wedge-shaped regions (1.13 ± 0.11 μm²/ms) was significantly lower (p = 0.0001) than that of benign wedge-shaped regions (1.52 ± 0.27 μm²/ms).

CONCLUSION

This study shows that a greater percentage of wedge-shaped features are malignant than was previously thought. Of importance, mpMRI (specifically, ADC maps) can distinguish between malignant and benign wedge-shaped features.

Prostate-Specific Membrane Antigen PET Imaging in Prostate Cancer: Opportunities and Challenges

The aim of this systematic review was to describe the characteristics of prostate-specific membrane antigen (PSMA)-targeting PET and their clinical applications in prostate cancer patients. There have been major strides in the design, synthesis of PSMA-targeting PET tracers over the past several years. PSMA-targeting PET tracers can be categorized, according to positron emitters and targeting strategies for the PSMA. The majority of PSMA PET studies has been focused on patients with biochemical recurrence, but additional values of PSMA PET have also been investigated for use in primary staging, treatment planning, response evaluation, and PSMA radioligand therapy. PSMA PET is expected to bring improvements in the management of patients, but the impact of improved diagnosis by PSMA on overall survival remains unanswered. Many challenges still await PSMA PET to expedite the use in the clinical practice. At this early stage, prospective multicenter trials are needed to validate the effectiveness and usefulness of PSMA PET.

The emerging role of imaging in prostate cancer secondary screening: multiparametric magnetic resonance imaging and the incipient incorporation of molecular imaging

An increasingly robust body of evidence indicates that multiparametric MRI (mpMRI) prior to prostate biopsy can improve the detection of clinically significant prostate cancer while avoiding unnecessary biopsies. As a result, the use of mpMRI and biopsy platforms that allow for the real-time fusion of mpMRI and transrectal ultrasound images is now routinely used in clinical practice. On the horizon, molecular imaging offers the promise of improved sensitivity relative to mpMRI and early data would suggest that the combination of mpMRI and positron emission tomography using radiotracers targeting prostate-specific membrane antigen provide a more accurate assessment than either modality alone. In this review, we examine the current role of imaging to aid in the initial diagnosis of prostate cancer.

A Supervised Learning Tool for Prostate Cancer Foci Detection and Aggressiveness Identification using Multiparametric magnetic resonance imaging/magnetic resonance spectroscopy imaging

Prostate cancer is the most frequently diagnosed cancer in men in the United States. The current main methods for diagnosing prostate cancer include prostate-specific antigen test and transrectal biopsy. Prostate-specific antigen screening has been criticized for overdiagnosis and unnecessary treatment, and transrectal biopsy is an invasive procedure with low sensitivity for diagnosis. We provided a quantitative tool using supervised learning with multiparametric imaging to be able to accurately detect cancer foci and its aggressiveness. A total of 223 specimens from patients who received magnetic resonance imaging (MRI) and magnetic resonance spectroscopy imaging prior to the surgery were studied. Multiparametric imaging included extracting T2-map, apparent diffusion coefficient (ADC) using diffusion-weighted MRI, Ktrans using dynamic contrast-enhanced MRI, and 3-dimensional-MR spectroscopy. A pathologist reviewed all 223 specimens and marked cancerous regions on each and graded them with Gleason scores, which served as the ground truth to validate our prediction model. In cancer aggressiveness prediction, the average area under the receiver operating characteristic curve (AUC) value was 0.73 with 95% confidence interval (0.72-0.74) and the average sensitivity and specificity were 0.72 (0.71-0.73) and 0.73 (0.71-0.75), respectively. For the cancer detection model, the average AUC value was 0.68 (0.66-0.70) and the average sensitivity and specificity were 0.73 (0.70-0.77) and 0.62 (0.60-0.68), respectively. Our method included capability to handle class imbalance using adaptive boosting with random undersampling. In addition, our method was noninvasive and allowed for nonsubjective disease characterization, which provided physician information to make personalized treatment decision.

Factors influencing urinary retention after transperineal template biopsy of the prostate: outcomes from a regional cancer centre

INTRODUCTION

Multi-parametric MRI (MP-MRI) prior to prostate biopsy is the investigation of choice for an elevated age-related PSA and abnormal digital rectal examination. MP-MRI in combination with transperineal template mapping biopsy has facilitated the development of the concept of targeted biopsies, either cognitively or with software fusion. Urinary retention is a recognised complication of transperineal prostate biopsy, with reported incidence being 1.6-11.4%. We present patient and procedure-related factors, which influence occurrence of urinary retention after transperineal template biopsy.

PATIENTS AND METHODS

Retrospective data collection of 243 consecutive cases of transperineal template biopsies performed at a single institution were recorded and analysed. Biopsies were taken using a standard 5-mm template in 4-6 sectors, depending on the prostate volume.

RESULTS

31/243 (12.8%) patients developed urinary retention, defined as patient discomfort and inability to micturate and bladder scan of ≥ 600 ml. Patients in the retention group were significantly older (mean 68.7 vs. 65.8 years, P = 0.034). Prostate volume was significantly greater in comparison with the non-retention group (mean 75.4 vs. 57.2 cc, P = 0.0016). The number of biopsies taken was positively correlated with urinary retention (median 35 vs. 32 biopsies, P = 0.045), and this was independent of prostate size (R² = 0.2). Presenting PSA, pre-operative flow and histopathological outcome were independent of urinary retention.

CONCLUSIONS

Factors resulting in an increased risk of urinary retention are advancing age (> 68.7 years); a larger prostate volume (> 75 cc); greater number of biopsies (> 35); greater severity of lower urinary tract symptoms prior to biopsy and diabetes. Targeted biopsies alone, instead of a full template, may avoid urinary retention in the high-risk groups identified.

Fast 3-T MR-guided transrectal prostate biopsy using an in-room tablet device for needle guide alignment: a feasibility study

OBJECTIVES

To assess the feasibility of adding a tablet device inside the scanner room to assist needle-guide alignment during magnetic resonance (MR)-guided transrectal prostate biopsy.

METHODS

Twenty patients with one cancer-suspicious region (CSR) with PI-RADS score ≥ 4 on diagnostic multiparametric MRI were prospectively enrolled. Two orthogonal scan planes of an MR fluoroscopy sequence (~3 images/s) were aligned to the CSR and needle-guide pivoting point. Targeting was achieved by manipulating the needle-guide under MR fluoroscopy feedback on the in-room tablet device. Technical feasibility and targeting success were assessed. Complications and biopsy procedure times were also recorded.

RESULTS

Needle-guide alignment with the in-room tablet device was technically successful in all patients and allowed sampling after a single alignment step in 19/20 (95%) CSRs (median size 14 mm, range: 4-45). Biopsy cores contained cancer in 18/20 patients. There were no per-procedural or post-biopsy complications. Using the tablet device, the mean time to first biopsy was 5.8 ± 1.0 min and the mean total procedure time was 23.7 ± 4.1 min.

CONCLUSIONS

Use of an in-room tablet device to assist needle-guide alignment was feasible and safe during MR-guided transrectal prostate biopsy. Initial experience indicates potential for procedure time reduction.

KEY POINTS

• Performing MR-guided prostate biopsy using an in-room tablet device is feasible. • CSRs could be sampled after a single alignment step in 19/20 patients. • The mean procedure time for biopsy with the tablet device was 23.7 min.

Genomic DNA Methylation-Derived Algorithm Enables Accurate Detection of Malignant Prostate Tissues

Introduction

The current methodology involving diagnosis of prostate cancer (PCa) relies on the pathology examination of prostate needle biopsies, a method with high false negative rates partly due to temporospatial, molecular, and morphological heterogeneity of prostate adenocarcinoma. It is postulated that molecular markers have a potential to assign diagnosis to a considerable portion of undetected prostate tumors. This study examines the genome-wide DNA methylation changes in PCa in search of genomic markers for the development of a diagnostic algorithm for PCa screening.

Methods

Archival PCa and normal tissues were assessed using genomic DNA methylation arrays. Differentially methylated sites and regions (DMRs) were used for functional assessment, gene-set enrichment and protein interaction analyses, and examination of transcription factor-binding patterns. Raw signal intensity data were used for identification of recurrent copy number variations (CNVs). Non-redundant fully differentiating cytosine-phosphate-guanine sites (CpGs), which did not overlap CNV segments, were used in an L1 regularized logistic regression model (LASSO) to train a classification algorithm. Validation of this algorithm was performed using a large external cohort of benign and tumor prostate arrays.

Results

Approximately 6,000 probes and 600 genomic regions showed significant DNA methylation changes, primarily involving hypermethylation. Gene-set enrichment and protein interaction analyses found an overrepresentation of genes related to cell communications, neurogenesis, and proliferation. Motif enrichment analysis demonstrated enrichment of tumor suppressor-binding sites nearby DMRs. Several of these regions were also found to contain copy number amplifications. Using four non-redundant fully differentiating CpGs, we trained a classification model with 100% accuracy in discriminating tumors from benign samples. Validation of this algorithm using an external cohort of 234 tumors and 92 benign samples yielded 96% sensitivity and 98% specificity. The model was found to be highly sensitive to detect metastatic lesions in bone, lymph node, and soft tissue, while being specific enough to differentiate the benign hyperplasia of prostate from tumor.

Conclusion

A considerable component of PCa DNA methylation profile represent driver events potentially established/maintained by disruption of tumor suppressor activity. As few as four CpGs from this profile can be used for screening of PCa.

Cognitive-Targeted versus Magnetic Resonance Imaging-Guided Prostate Biopsy in Prostate Cancer Detection

Introduction

Purpose of this study is to evaluate the detection rates of prostate cancer (PCa) for cognitive-targeted biopsy (CTB) in comparison with magnetic resonance imaging (MRI)-guided biopsy (MRGB) related to prostate imaging reporting and data system (PI-RADS) score, lesion location and lesion volume. Furthermore, the addition of systematic transrectal ultrasound-guided biopsy (TRUS-GB) to CTB is evaluated.

Materials and Methods

We included all patients with cancer-suspicious lesions on 3-Tesla multiparametric MRI who underwent either CTB and additional TRUS-GB or only MRGB (in-bore) in Haga Teaching Hospital between January 2013 and January 2015.

Results

In total 219 patients were included: 64 CTB + TRUS-GB and 155 MRGB. In 32 (50%) men with CTB was positive for PCa. PI-RADS 3-, 4- and 5-lesions were in 17, 69 and 95% positive, respectively. In 100 men (65%) with MRGB was positive for PCa. Detection rates for PI-RADS 3-, 4- and 5-lesions were 10, 77 and 89%, respectively. CTB missed 4 (11%) low-grade tumors detected by TRUS-GB. In lesions between 0-1.5 ml PCa were significantly more often detected with MRGB than with CTB (69 vs. 39%).

Conclusion

CTB has a high detection rate of PCa in men with cancer-suspicious lesions on MRI. Correction for lesion volume shows that in lesions < 1.5 ml MRGB is more accurate than CTB. The addition of TRUS-GB to CTB can safely be avoided without missing any high grade PCa.

Microscale characterization of prostate biopsies tissues using optical coherence elastography and second harmonic generation imaging

Photonics, especially optical coherence elastography (OCE) and second harmonic generation (SHG) imaging are novel high-resolution imaging modalities for characterization of biological tissues. Following our preliminary experience, we hypothesized that OCE and SHG imaging would delineate the microstructure of prostate tissue and aid in distinguishing cancer from the normal benign prostatic tissue. Furthermore, these approaches may assist in characterization of the grade of cancer, as well. In this study, we confirmed a high diagnostic accuracy of OCE and SHG imaging in the detection and characterization of prostate cancer for a large set of biopsy tissues obtained from men suspected to have prostate cancer using transrectal ultrasound (TRUS). The two techniques and methods described here are complementary, one depicts the stiffness of tissues and the other illustrates the orientation of collagen structure around the cancerous lesions. The results showed that stiffness of cancer tissue was ~57.63% higher than that of benign tissue (Young's modulus of 698.43±125.29 kPa for cancerous tissue vs 443.07±88.95 kPa for benign tissue with OCE. Using histology as a reference standard and 600 kPa as a cut-off threshold, the data analysis showed sensitivity and specificity of 89.6 and 99.8%, respectively. Corresponding positive and negative predictive values were 99.5 and 94.6%, respectively. There was a significant difference noticed in terms of Young's modulus for different Gleason scores estimated by OCE (P-value<0.05). For SHG, distinct patterns of collagen distribution were seen for different Gleason grade disease with computed quantification employing a ratio of anisotropic to isotropic (A:I ratio) and this correlated with disease aggressiveness.

In-bore MRI-guided biopsy: can it optimize the need for periodic biopsies in prostate cancer patients undergoing active surveillance? A pilot test-retest reliability study

OBJECTIVE

To evaluate the test-retest reliability of repeated in-bore MRI-guided prostate biopsy (MRGB).

METHODS

19 lesions in 7 patients who had consecutive MRGBs were retrospectively analysed. Five patients had 2 consecutive MRGBs and two patients had 3 consecutive MRGBs. Both multiparametric MRI and MRGBs were performed using a 3T MRI scanner. Pathology results were categorized into benign, suspicious and malignant. Consistency between first and subsequent biopsy results were analysed as well as the negative predictive value (NPV) for prostate cancer.

RESULTS

15 lesions (≈79%) had matching second biopsy and 4 (21%) had non-matching second biopsy. Lesions with both Prostate Imaging - Reporting and Data System(PIRADS) categories 1 and 4 were all benign and had matching pathology results. Lesions with non-matching results had PIRADS categories 2, 3 and 5. NPV for prostate cancer in first biopsy was 87.5%. Overall agreement was 78.9% and overall disagreement was 21.1%.κ = 0.55 denoting moderate agreement (p = 0.002). 10/19 lesions had a third biopsy session. 9/10 (90%) had matching pathology results across the three biopsy sessions and all matching lesions were benign.

CONCLUSION

In-bore MRI-guided prostate biopsy may have a better reliability for repeat biopsies compared to TRUS biopsy. Final conclusion awaits a prospective analysis on a larger cohort of patients. Advances in knowledge: This pilot study showed that repeated prostate in-bore MRI-guided prostate biopsy may have better reliability compared to TRUS biopsy with a suggested high NPV.

Characterization and stratification of prostate lesions based on comprehensive multiparametric MRI using detailed whole-mount histopathology as a reference standard

The purpose of this study was to characterize prostate cancer (PCa) based on multiparametric MR (mpMR) measures derived from MRI, diffusion, spectroscopy, and dynamic contrast-enhanced (DCE) MRI, and to validate mpMRI in detecting PCa and predicting PCa aggressiveness by correlating mpMRI findings with whole-mount histopathology. Seventy-eight men with untreated PCa received 3 T mpMR scans prior to radical prostatectomy. Cancerous regions were outlined, graded, and cancer amount estimated on whole-mount histology. Regions of interest were manually drawn on T₂ -weighted images based on histopathology. Logistic regression was used to identify optimal combinations of parameters for the peripheral zone and transition zone to separate: (i) benign from malignant tissues; (ii) Gleason score (GS) ≤3 + 3 disease from ≥GS3 + 4; and (iii) ≤ GS3 + 4 from ≥GS4 + 3 cancers. The performance of the models was assessed using repeated fourfold cross-validation. Additionally, the performance of the logistic regression models created under the assumption that one or more modality has not been acquired was evaluated. Logistic regression models yielded areas under the curve (AUCs) of 1.0 and 0.99 when separating benign from malignant tissues in the peripheral zone and the transition zone, respectively. Within the peripheral zone, combining choline, maximal enhancement slope, apparent diffusion coefficient (ADC), and citrate measures for separating ≤GS3 + 3 from ≥GS3 + 4 PCa yielded AUC = 0.84. Combining creatine, choline, and washout slope yielded AUC = 0.81 for discriminating ≤GS3 + 4 from ≥GS4 + 3 disease. Within the transition zone, combining washout slope, ADC, and creatine yielded AUC = 0.93 for discriminating ≤GS3 + 3 and ≥GS3 + 4 cancers. When separating ≤GS3 + 4 from ≥GS4 + 3 PCa, combining choline and washout slope yielded AUC = 0.92. MpMRI provides excellent separation between benign tissues and PCa, and across PCa tissues of different aggressiveness. The final models prominently feature spectroscopy and DCE-derived metrics, underlining their value within a comprehensive mpMRI examination.

Validation of Prostate Imaging-Reporting and Data System Version 2: A Retrospective Analysis

PURPOSE

Use of magnetic resonance imaging (MRI)/transrectal ultrasound fusion biopsies to determine the accuracy of multiparametric MRI (mpMRI), using Prostate Imaging-Reporting and Data System version 2 (PI-RADSv2), for detecting clinically significant prostate cancer in the overall gland and specifically the peripheral zone (PZ) and transitional zone (TZ).

METHODS

A retrospective analysis of patients who underwent fusion biopsy identified 137 men with 231 prostate lesions was approved by the Institutional Review Board. Subjects initially classified under PI-RADSv1 criteria were regraded using PI-RADSv2 by a radiologist blinded to PI-RADSv1 score and biopsy results. Spearman correlation, chi-squared, and logistic regression analysis were performed.

RESULTS

There was positive correlation between PI-RADSv2 and Gleason scores (P < 0.001). In the PZ, mpMRI demonstrated 100% sensitivity, 100% negative predictive value, and 35.9% positive predictive value, compared to 100%, 100%, and 27.1%, respectively, for TZ lesions. When predicting clinically significant prostate cancer, the PI-RADSv2 area under the curve for TZ lesions was 0.844 (95% CI: 0.753-0.935, P < 0.001) and 0.769 (95% CI: 0.684-0.854, P < 0.001) for PZ lesions. Combining PI-RADSv2 with additional risk factors (body mass index, prostate-specific antigen density, digital rectal examination) improved the area under curve.

CONCLUSIONS

PI-RADSv2 achieves excellent sensitivity and negative predictive value for both PZ and TZ lesions.

Analysis of histological findings obtained combining US/mp-MRI fusion-guided biopsies with systematic US biopsies: mp-MRI role in prostate cancer detection and false negative

AIMS AND OBJECTIVES

To evaluate the diagnostic accuracy of mp-MRI correlating US/mp-MRI fusion-guided biopsy with systematic random US-guided biopsy in prostate cancer diagnosis.

MATERIALS AND METHODS

137 suspected prostatic abnormalities were identified on mp-MRI (1.5T) in 96 patients and classified according to PI-RADS score v2. All target lesions underwent US/mp-MRI fusion biopsy and prostatic sampling was completed by US-guided systematic random 12-core biopsies. Histological analysis and Gleason score were established for all the samples, both target lesions defined by mp-MRI, and random biopsies. PI-RADS score was correlated with the histological results, divided in three groups (benign tissue, atypia and carcinoma) and with Gleason groups, divided in four categories considering the new Grading system of the ISUP 2014, using t test. Multivariate analysis was used to correlate PI-RADS and Gleason categories to PSA level and abnormalities axial diameter. When the random core biopsies showed carcinoma (mp-MRI false-negatives), PSA value and lesions Gleason median value were compared with those of carcinomas identified by mp-MRI (true-positives), using t test.

RESULTS

There was statistically significant difference between PI-RADS score in carcinoma, atypia and benign lesions groups (4.41, 3.61 and 3.24, respectively) and between PI-RADS score in Gleason < 7 group and Gleason > 7 group (4.14 and 4.79, respectively). mp-MRI performance was more accurate for lesions > 15 mm and in patients with PSA > 6 ng/ml. In systematic sampling, 130 (11.25%) mp-MRI false-negative were identified. There was no statistic difference in Gleason median value (7.0 vs 7.06) between this group and the mp-MRI true-positives, but a significant lower PSA median value was demonstrated (7.08 vs 7.53 ng/ml).

CONCLUSION

mp-MRI remains the imaging modality of choice to identify PCa lesions. Integrating US-guided random sampling with US/mp-MRI fusion target lesions sampling, 3.49% of false-negative were identified.

Zinc as an Imaging Biomarker of Prostate Cancer

Zinc has long been the focus of many biological investigations because of its essential role in biology including a catalytic role in many enzymes, a structural role in the many zinc finger proteins, and a physiological role in many secretory cell processes. Divalent zinc is known to be highly abundant in healthy prostate tissues and lower in prostate cancer (PCa). Given the need for newer diagnostic methods for detection of prostate cancer, zinc-responsive probes of various types have been considered as imaging tools for detecting tissue levels of zinc. Among them, recent zinc-responsive MRI probes show great promise for non-invasive detection of zinc ion secretion from the prostate and other tissues in vivo. In this review, we summarize the need for new diagnostic tools and demonstrate how responsive zinc probes and MRI could satisfy this unmet need.

Current Management Strategy for Active Surveillance in Prostate Cancer

PURPOSE OF REVIEW

Active surveillance has been increasingly utilized as a strategy for the management of favorable-risk, localized prostate cancer. In this review, we describe contemporary management strategies of active surveillance, with a focus on traditional stratification schemes, new prognostic tools, and patient outcomes.

RECENT FINDINGS

Patient selection, follow-up strategy, and indication for delayed intervention for active surveillance remain centered around PSA, digital rectal exam, and biopsy findings. Novel tools which include imaging, biomarkers, and genetic assays have been investigated as potential prognostic adjuncts; however, their role in active surveillance remains institutionally dependent. Although 30-50% of patients on active surveillance ultimately undergo delayed treatment, the vast majority will remain free of metastasis with a low risk of dying from prostate cancer. The optimal method for patient selection into active surveillance is unknown; however, cancer-specific mortality rates remain excellent. New prognostication tools are promising, and long-term prospective, randomized data regarding their use in active surveillance will be beneficial.