Prostate cancer management: long-term beliefs, epidemic developments in the early twenty-first century and 3PM dimensional solutions

In the early twenty-first century, societies around the world are facing the paradoxal epidemic development of PCa as a non-communicable disease. PCa is the most frequently diagnosed cancer for men in several countries such as the USA. Permanently improving diagnostics and treatments in the PCa management causes an impressive divergence between, on one hand, permanently increasing numbers of diagnosed PCa cases and, on the other hand, stable or even slightly decreasing mortality rates. Still, aspects listed below are waiting for innovate solutions in the context of predictive approaches, targeted prevention and personalisation of medical care (PPPM / 3PM).A.PCa belongs to the cancer types with the highest incidence worldwide. Corresponding economic burden is enormous. Moreover, the costs of treating PCa are currently increasing more quickly than those of any other cancer. Implementing individualised patient profiles and adapted treatment algorithms would make currently too heterogeneous landscape of PCa treatment costs more transparent providing clear "road map" for the cost saving.B.PCa is a systemic multi-factorial disease. Consequently, predictive diagnostics by liquid biopsy analysis is instrumental for the disease prediction, targeted prevention and curative treatments at early stages.C.The incidence of metastasising PCa is rapidly increasing particularly in younger populations. Exemplified by trends observed in the USA, prognosis is that the annual burden will increase by over 40% in 2025. To this end, one of the evident deficits is the reactive character of medical services currently provided to populations. Innovative screening programmes might be useful to identify persons in suboptimal health conditions before the clinical onset of metastasising PCa. Strong predisposition to systemic hypoxic conditions and ischemic lesions (e.g. characteristic for individuals with Flammer syndrome phenotype) and low-grade inflammation might be indicative for specific phenotyping and genotyping in metastasising PCa screening and disease management. Predictive liquid biopsy tests for CTC enumeration and their molecular characterisation are considered to be useful for secondary prevention of metastatic disease in PCa patients.D.Particular rapidly increasing PCa incidence rates are characteristic for adolescents and young adults aged 15-40 years. Patients with early onset prostate cancer pose unique challenges; multi-factorial risks for these trends are proposed. Consequently, multi-level diagnostics including phenotyping and multi-omics are considered to be the most appropriate tool for the risk assessment, prediction and prognosis. Accumulating evidence suggests that early onset prostate cancer is a distinct phenotype from both aetiological and clinical perspectives deserving particular attention from view point of 3P medical approaches.

Combining transrectal ultrasound and CT for image-guided adaptive brachytherapy of cervical cancer: Proof of concept

PURPOSE

To investigate the feasibility of a treatment planning workflow for three-dimensional image-guided cervix cancer brachytherapy, combining volumetric transrectal ultrasound (TRUS) for target definition with CT for dose optimization to organs at risk (OARs), for settings with no access to MRI.

METHODS AND MATERIALS

A workflow for TRUS/CT-based volumetric treatment planning was developed, based on a customized system including ultrasound probe, stepper unit, and software for image volume acquisition. A full TRUS/CT-based workflow was simulated in a clinical case and compared with MR- or CT-only delineation. High-risk clinical target volume was delineated on TRUS, and OARs were delineated on CT. Manually defined tandem/ring applicator positions on TRUS and CT were used as a reference for rigid registration of the image volumes. Treatment plan optimization for TRUS target and CT organ volumes was performed and compared to MRI and CT target contours.

RESULTS

TRUS/CT-based contouring, applicator reconstruction, image fusion, and treatment planning were feasible, and the full workflow could be successfully demonstrated. The TRUS/CT plan fulfilled all clinical planning aims. Dose-volume histogram evaluation of the TRUS/CT-optimized plan (high-risk clinical target volume D₉₀, OARs D_2cm³ for) on different image modalities showed good agreement between dose values reported for TRUS/CT and MRI-only reference contours and large deviations for CT-only target parameters.

CONCLUSIONS

A TRUS/CT-based workflow for full three-dimensional image-guided cervix brachytherapy treatment planning seems feasible and may be clinically comparable to MRI-based treatment planning. Further development to solve challenges with applicator definition in the TRUS volume is required before systematic applicability of this workflow.

A deep learning approach for real time prostate segmentation in freehand ultrasound guided biopsy

Targeted prostate biopsy, incorporating multi-parametric magnetic resonance imaging (mp-MRI) and its registration with ultrasound, is currently the state-of-the-art in prostate cancer diagnosis. The registration process in most targeted biopsy systems today relies heavily on accurate segmentation of ultrasound images. Automatic or semi-automatic segmentation is typically performed offline prior to the start of the biopsy procedure. In this paper, we present a deep neural network based real-time prostate segmentation technique during the biopsy procedure, hence paving the way for dynamic registration of mp-MRI and ultrasound data. In addition to using convolutional networks for extracting spatial features, the proposed approach employs recurrent networks to exploit the temporal information among a series of ultrasound images. One of the key contributions in the architecture is to use residual convolution in the recurrent networks to improve optimization. We also exploit recurrent connections within and across different layers of the deep networks to maximize the utilization of the temporal information. Furthermore, we perform dense and sparse sampling of the input ultrasound sequence to make the network robust to ultrasound artifacts. Our architecture is trained on 2,238 labeled transrectal ultrasound images, with an additional 637 and 1,017 unseen images used for validation and testing, respectively. We obtain a mean Dice similarity coefficient of 93%, a mean surface distance error of 1.10 mm and a mean Hausdorff distance error of 3.0 mm. A comparison of the reported results with those of a state-of-the-art technique indicates statistically significant improvement achieved by the proposed approach.

Magnetic Resonance Imaging-Ultrasound Fusion-Guided Prostate Biopsy: Review of Technology, Techniques, and Outcomes

Transrectal ultrasound (TRUS)-guided (12-14 core) systematic biopsy of the prostate is the recommended standard for patients with suspicion of prostate cancer (PCa). Advances in imaging have led to the application of magnetic resonance imaging (MRI) for the detection of PCa with subsequent development of software-based co-registration allowing for the integration of MRI with real-time TRUS during prostate biopsy. A number of fusion-guided methods and platforms are now commercially available with common elements in image and analysis and planning. Implementation of fusion-guided prostate biopsy has now been proven to improve the detection of clinically significant PCa in appropriately selected patients.

Use of transrectal ultrasound for high dose rate interstitial brachytherapy for patients of carcinoma of uterine cervix

OBJECTIVE

Transrectal ultrasound (TRUS) has been widely used for guiding prostate implants, but not much for interstitial brachytherapy (IBT) of cervix cancer. The aim of our study is to report our experience with TRUS guided high dose rate (HDR) IBT in patients with carcinoma of uterine cervix.

METHODS

During the year 2005-2006, 25 patients of cervical cancer not suitable for intracavitary radiotherapy (ICRT), were enrolled in this prospective study. We used B-K Medical USG machine (Falcon 2101) equipped with a TRUS probe (8658) having a transducer of 7.5 MHz for IBT. Post procedure, a CT scan was done for verification of needle position and treatment planning. Two weekly sessions of HDR IBT of 8-10 Gy each were given after pelvic external beam radiation therapy.

RESULTS

A total of 40 IBT procedures were performed in 25 patients. Average duration of implant procedure was 50 minutes. There was no uterine perforation in any of 11 patients in whom central tandem was used. CT scan did not show needle perforation of bladder/rectum in any of the patients. During perioperative period, only 1 procedure (2.5%) was associated with hematuria which stopped within 6 hours. Severe late toxicity was observed in 3 (12%) patients. Overall pelvic control rate was 64%.

CONCLUSION

Our experience suggests that TRUS is a practical and effective imaging device for guiding the IBT procedure of cervical cancer patients. It helps in accurate placements of needles thus avoiding the injury to normal pelvic structures.

Recent Advances and Current Role of Transperineal Prostate Biopsy

"Approximately 1 million prostate biopsies are performed each year in the United States. This procedure has traditionally been performed using a transrectal approach, which is associated with a significant risk of infectious complications including sepsis. In recent years, transperineal prostate biopsy has been increasingly adopted due to its lower associated infectious risk. In this review, we explore the benefits of the transperineal approach for performing prostate biopsy and detail technical advancements that have allowed for this procedure to now be routinely performed in the outpatient settings under local anesthesia."

The Comparison of Imaging and Clinical Methods to Estimate Prostate Volume: A Single-Centre Retrospective Study

BACKGROUND

Prostate volume (PV) is a useful tool in risk stratification, diagnosis, and follow-up of numerous prostatic diseases including prostate cancer and benign prostatic hypertrophy. There is currently no accepted ideal PV measurement method.

OBJECTIVE

This study compares multiple means of PV estimation, including digital rectal examination (DRE), transrectal ultrasound (TRUS), and magnetic resonance imaging (MRI), and radical prostatectomy specimens to determine the best volume measurement style.

METHODS

A retrospective, observational, single-site study with patients identified using an institutional database was performed. A total of 197 patients who underwent robot-assisted radical prostatectomy were considered. Data collected included age, serum PSA at the time of the prostate biopsy, clinical T stage, Gleason score, and PVs for each of the following methods: DRE, TRUS, MRI, and surgical specimen weight (SPW) and volume.

RESULTS

A paired t test was performed, which reported a statistically significant difference between PV measures (DRE, TRUS, MRI ellipsoid, MRI bullet, SP ellipsoid, and SP bullet) and the actual prostate weight. Lowest differences were reported for SP ellipsoid volume (M = -2.37; standard deviation [SD] = 10.227; t[167] = -3.011; and p = 0.003), MRI ellipsoid volume (M = -4.318; SD = 9.53; t[167] = -5.87; and p = 0.000), and MRI bullet volume (M = 5.31; SD = 10.77; t[167] = 6.387; and p = 0.000).

CONCLUSION

The PV obtained by MRI has proven to correlate with the PV obtained via auto-segmentation software as well as actual SPW, while also being more cost-effective and time-efficient. Therefore, demonstrating that MRI estimated the PV is an adequate method for use in clinical practice for therapeutic planning and patient follow-up.

Prospective Evaluation of 68Ga-labeled Prostate-specific Membrane Antigen Ligand Positron Emission Tomography/Computed Tomography in Primary Prostate Cancer Diagnosis

BACKGROUND

Positron emission tomography (PET)/computed tomography (CT) with ⁶⁸Ga-labeled prostate-specific membrane antigen ligand (⁶⁸Ga-PSMA) may represent the most promising alternative to multiparametric magnetic resonance imaging (mpMRI) for prostate cancer (PCa) diagnosis.

OBJECTIVE

To test the diagnostic performance of ⁶⁸Ga-PSMA PET/CT in this clinical context.

DESIGN, SETTING, AND PARTICIPANTS

From January 2017 to December 2018 we prospectively enrolled 97 patients with persistently elevated prostate-specific antigen and/or Prostate Health Index score, negative digital rectal examination, and previous negative biopsy. We also included patients with either negative mpMRI or contraindications to or positive mpMRI but previous negative biopsy.

INTERVENTION

Patients underwent 68Ga-PSMA PET/CT with additional pelvic reconstruction.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint of the study was the diagnostic performance of ⁶⁸Ga-PSMA PET/CT in detecting malignant lesions and clinically significant PCa (Gleason score [GS] ≥7).

RESULTS AND LIMITATIONS

⁶⁸Ga-PSMA PET/transrectal ultrasound fusion biopsy was performed in 64 of 97 patients (66%) for 114 regions of interest (ROIs). Forty patients (41%) had already undergone mpMRI with either a negative result for PCa (n = 15; 22 ROIs) or a positive mpMRI result but a previous negative biopsy. According to pathology, 23 patients (36%) had evidence of PCa: eight (16 ROIs) with GS 6, 13 (21 ROIs) with GS 7 (3 + 4 or 4 + 3), one (2 ROIs) with GS 8, and one (2 ROIs) with GS 10. Clinically significant PCa was identified in four patients with previous negative mpMRI (25%). PET/CT demonstrated PCa in seven patients (14 ROIs) with previous positive mpMRI and negative biopsy. The median maximum standardized uptake value (SUVmax) and median SUV ratio were significantly higher for PCa lesions than for benign lesions (p <  0.001). Optimal cutoff points obtained for SUVmax (>5.4) and SUV ratio (>2.2) could identify clinically significant PCa with accuracy of 81% and 90%, respectively.

CONCLUSIONS

In our cohort of patients with high suspicion of cancer,⁶⁸Ga-PSMA PET/CT was capable of detecting malignancy and accurately identifying clinically relevant PCa.

PATIENT SUMMARY

Positron emission tomography/computed tomography with a ⁶⁸Ga-labeled ligand for prostate-specific membrane antigen is capable of detecting prostate cancer in patients with a high suspicion of cancer and a previous negative biopsy.

Pain during transrectal ultrasound-guided prostate biopsy and the role of periprostatic nerve block: what radiologists should know

Early prostate cancers are best detected with transrectal ultrasound (TRUS)-guided core biopsy of the prostate. Due to increased longevity and improved prostate cancer screening, more men are now subjected to TRUS-guided biopsy. To improve the detection rate of early prostate cancer, the current trend is to increase the number of cores obtained. The significant pain associated with the biopsy procedure is usually neglected in clinical practice. Although it is currently underutilized, the periprostatic nerve block is an effective technique to mitigate pain associated with prostate biopsy. This article reviews contemporary issues pertaining to pain during prostate biopsy and discusses the practical aspects of periprostatic nerve block.

Optimization of prostate biopsy - Micro-Ultrasound versus MRI (OPTIMUM): A 3-arm randomized controlled trial evaluating the role of 29 MHz micro-ultrasound in guiding prostate biopsy in men with clinical suspicion of prostate cancer

BACKGROUND

Micro-ultrasound (microUS) is a novel ultrasound-based imaging modality which has demonstrated the ability to visualize prostate cancer. Multiparametric MRI/ultrasound (mpMRI/US) fusion has recognized advantages for the performance of prostate biopsy, however, it encompasses additional cost, time and technical expertise to performing prostate biopsy in comparison to conventional trans-rectal ultrasound biopsy. MicroUS may simplify and optimize this pathway.

METHODS

OPTIMUM is a 3-arm randomized controlled trial comparing microUS guided biopsy with MRI/US fusion and MRI/MicroUS "contour-less" fusion. This trial will investigate whether microUS alone, or in combination with mpMRI, provides effective guidance during prostate biopsy for the detection of clinically significant prostate cancer (csPCa) for biopsy naïve subjects. 1200 subjects will be randomized. The economic impact will be evaluated.

RESULTS

The rate of csPCa (defined as Grade Group 2 and above) in each arm will be compared. The primary hypothesis is non-inferiority of csPCa rate between the MRI/US fusion arm and the microUS-only arm (including the blinded microUS-only portion of the MRI/MicroUS arm). As a secondary objective, the csPCa rate between MRI/MicroUS fusion and MRI/US fusion arms will also be compared. Other secondary objectives include the increase in rate of patients diagnosed with csPCa due to each type of sample (mpMRI targeted, microUS targeted, systematic), the negative predictive value of each imaging modality, and a health economic analysis of the procedures in each arm.

CONCLUSIONS

OPTIMUM will determine whether microUS can be used as an alternative to MRI/US fusion biopsy. The trial will also evaluate the efficacy of the simplified "contour-less" MRI/MicroUS fusion procedure. The adoption of the microUS technique will increase the proportion of men who can benefit from modern imaging-centric diagnostic strategies, and may help reduce variability, complexity, waiting time and cost within the diagnostic pathway.

Free-hand transperineal prostate biopsy provides acceptable cancer detection and minimizes risk of infection: evolving experience with a 10-sector template

INTRODUCTION AND OBJECTIVES

Free-hand transperineal prostate (fTP-Bx) biopsy offers an alternative to transrectal prostate biopsy (TRUS-Bx) in the diagnosis of prostate cancer. Our objectives were to determine whether fTP-Bx achieves cancer detection rates comparable to historic TRUS-Bx cohorts; to determine infectious and other complications associated with fTP-B; and to propose a standardized fTP-Bx template.

PATIENTS AND METHODS

We present a single institution, retrospective review of fTP-Bx in 1,000 men with elevated prostate-specific antigen, abnormal digital rectal examination, or on an active surveillance protocol. A fan-like biopsy scheme was used in 883 patients. A 10-sector prostate biopsy template was developed for use in the final 117 patients. The primary outcome was detection of any cancer and detection of clinically significant cancer (Grade Group ≥ 2). Secondary outcomes included procedural specifics and complications. Chi Square and Mann-Whitney U were used for analysis of categorical and continuous variables, respectively.

RESULTS

The median age of the cohort was 68 (interquartile range 61-74) years, and the median prostate-specific antigen was 7.9 (interquartile range 5.5-11.9) ng/ml. Total cancer (60.7%) and clinically significant cancer (40.3%) detection for fTP-Bx were comparable to those reported for TRUS-Bx. Detection of any cancer (70.9% vs. 59.3%, P < 0.01) and clinically significant cancer (51.3% vs. 38.9%, P = 0.01) was higher using the 10-sector biopsy template relative to the fan-like pattern. No patients were hospitalized for sepsis and no culture-proven urinary tract infections were diagnosed.

CONCLUSION

Cancer detection rates using fTP-Bx are comparable to TRUS-Bx, and fTP-Bx nearly eliminates the risk of infection. We propose a 10-sector biopsy template for fTP-Bx that easily translates to established MRI prostate sector maps for use in clinical care and future research studies exploring the efficacy of MRI-guided fTP-Bx.

Classification of focal prostatic lesions on transrectal ultrasound (TRUS) and the accuracy of TRUS to diagnose prostate cancer

Objective

To improve the diagnostic efficacy of transrectal ultrasound (TRUS)-guided targeted prostatic biopsies, we have suggested the use of a new scoring system for the prediction of malignancies regarding the characteristics of focal suspicious lesions as depicted on TRUS.

Materials and Methods

A total of 350 consecutive patients with or without prostate cancer who underwent targeted biopsies for 358 lesions were included in the study. The data obtained from participants were randomized into two groups; the training set (n = 240) and the test set (n = 118). The characteristics of focal suspicious lesions were evaluated for the training set and the correlation between TRUS findings and the presence of a malignancy was analyzed. Multiple logistic regression analysis was used to identify variables capable of predicting prostatic cancer. A scoring system that used a 5-point scale for better malignancy prediction was determined from the training set. Positive predictive values for malignancy prediction and the diagnostic accuracy of the scored components with the use of receiver operating characteristic curve analysis were evaluated by test set analyses.

Results

Subsequent multiple logistic regression analysis determined that shape, margin irregularity, and vascularity were factors significantly and independently associated with the presence of a malignancy. Based on the use of the scoring system for malignancy prediction derived from the significant TRUS findings and the interactions of characteristics, a positive predictive value of 80% was achieved for a score of 4 when applied to the test set. The area under the receiver operating characteristic curve (AUC) for the overall lesion score was 0.81.

Conclusion

We have demonstrated that a scoring system for malignancy prediction developed for the characteristics of focal suspicious lesions as depicted on TRUS can help predict the outcome of TRUS-guided biopsies.

Contrast-enhanced harmonic ultrasonography for the assessment of prostate cancer aggressiveness: a preliminary study

OBJECTIVE

To determine whether contrast-enhanced harmonic ultrasonography can be used to predict the aggressiveness of prostate cancer.

MATERIALS AND METHODS

Contrast-enhanced harmonic ultrasonography was performed in 103 patients suspected of prostate cancer before biopsy. Time intensity curves were reconstructed for systematic biopsy sites and sonographic abnormalities. The characteristics of the curves were described using hemodynamic indices including arrival time (AT), time-to-peak (TTP), and peak intensity (PI). The differences of hemodynamic indices between high-grade and low-grade cancer were analyzed and the correlations between the hemodynamic indices and biopsy Gleason score were studied.

RESULTS

Prostate cancer was detected in 41 of 103 patients and there were significant differences in the hemodynamic indices between the biopsy sites of the non-malignant patients and prostate cancer lesions (p < 0.05). The prostate biopsies revealed 154 prostate cancer lesions, including 31 low-grade lesions and 123 high-grade lesions. The hemodynamic indices AT and TTP of high-grade tumors were significantly shorter than those of low-grade tumors (p = 0.001, 0.002). In addition, high-grade peripheral zone (PZ) tumors had higher PI than low-grade PZ tumors (p = 0.009). The PZ prostate cancer Gleason score correlated with PI, AT and TTP, with Spearman correlation coefficients of 0.223, -0.335, and -0.351, respectively (p = 0.013, < 0.001 and < 0.001).

CONCLUSION

Contrast-enhanced ultrasound measurements of hemodynamic indices correlate with the prostate cancer Gleason score.

A 12-year follow-up of ANNA/C-TRUS image-targeted biopsies in patients suspicious for prostate cancer

PURPOSE

PSA screening has been rehabilitated. PSA is not specific and can be elevated by benign reasons. Additionally, a subgroup of patients with prostate hyperplasia may harbor prostate cancer (PCa). During monitoring, the clinician aims to detect significant tumors in time, submitting patients to minimal psychological and physical burden, especially in men with high serum PSA and repeat biopsies. We aimed to determine long-term outcomes with respect to ANNA/C-TRUS ability to detect PCa with six targeted biopsies.

METHODS

A subset of 71 patients were enrolled. During monitoring, they were subjected to primary, secondary, or even multiple prostate biopsies when needed. Protocol monitoring included PSA measurements, digital rectal examination (DRE) and imaging.

RESULTS

The median follow-up was 12 years. Forty-one patients had a history of negative systematic random biopsies (1-3 sessions). Their age ranges 62-85 years, PSA 0.5-47.3 ng/ml, and the median prostate volume 11-255 cc. During monitoring, 15 patients were diagnosed with PCa. Only two harbored aggressive tumors. The median time to diagnosis was 6 years. All PCa patients are free from biochemical relapse. From the remaining 56 patients, 11 did not have any biopsies, 12 had one, 13 had two, and 20 had three or more biopsy sessions.

CONCLUSIONS

ANNA/C-TRUS is a useful method monitoring patients with a risk of PCa. 50-75% of the usually performed biopsy cores could be spared and, after 12 years, 97% of the patients were either without evidence of a PCa or were diagnosed with a good prognosis tumor.

Hematospermia--the added value of transrectal ultrasound to clinical evaluation: is transrectal ultrasound necessary for evaluation of hematospermia?

Hematospermia is usually caused by nonspecific inflammation of the prostate and seminal vesicles. Transrectal ultrasound (TRUS) is a safe and inexpensive modality for evaluating patients with hematospermia. The aim of this study is to describe the findings of TRUS and its contribution to patients' management. A total of 115 consecutive patients presented with hematospermia and evaluated with TRUS between 2006 and 2012. All patients exhibited an abnormality in the TRUS examination. A 12-core TRUS-guided biopsy of the prostate was taken from 10 patients, but none of these samples were positive for tumor. In the vast majority of cases, a benign cause can be identified using TRUS. These causes usually do not require treatment.

A Prospective Multicenter Comparison Study of Risk-adapted Ultrasound-directed and Magnetic Resonance Imaging-directed Diagnostic Pathways for Suspected Prostate Cancer in Biopsy-naïve Men

BACKGROUND

European Association of Urology guidelines recommend a risk-adjusted biopsy strategy for early detection of prostate cancer in biopsy-naïve men. It remains unclear which strategy is most effective. Therefore, we evaluated two risk assessment pathways commonly used in clinical practice.

OBJECTIVE

To compare the diagnostic performance of a risk-based ultrasound (US)-directed pathway (Rotterdam Prostate Cancer Risk Calculator [RPCRC] #3; US volume assessment) and a magnetic resonance imaging (MRI)-directed pathway.

DESIGN, SETTING, AND PARTICIPANTS

This was a prospective multicenter study (MR-PROPER) with 1:1 allocation among 21 centers (US arm in 11 centers, MRI arm in ten). Biopsy-naïve men with suspicion of prostate cancer (age ≥50 yr, prostate-specific antigen 3.0-50 ng/ml, ± abnormal digital rectal examination) were included.

INTERVENTION

Biopsy-naïve men with elevated risk of prostate cancer, determined using RPCRC#3 in the US arm and Prostate Imaging Reporting and Data System scores of 3-5 in the MRI arm, underwent systematic biopsies (US arm) or targeted biopsies (MRI arm).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome was the proportion of men with grade group (GG) ≥2 cancer. Secondary outcomes were the proportions of biopsies avoided and GG 1 cancers detected. Categorical (nonparametric) data were assessed using the Mann-Whitney U test and χ² tests.

RESULTS AND LIMITATIONS

A total of 1965 men were included in the intention-to-treat population (US arm n = 950, MRI arm n = 1015). The US and MRI pathways detected GG ≥2 cancers equally well (235/950, 25% vs 239/1015, 24%; difference 1.2%, 95% confidence interval [CI] -2.6% to 5.0%; p = 0.5). The US pathway detected more GG 1 cancers than the MRI pathway (121/950, 13% vs 84/1015, 8.3%; difference 4.5%, 95% CI 1.8-7.2%; p < 0.01). The US pathway avoided fewer biopsies than the MRI pathway (403/950, 42% vs 559/1015, 55%; difference -13%, 95% CI -17% to -8.3%; p < 0.01). Among men with elevated risk, more GG ≥2 cancers were detected in the MRI group than in the US group (52% vs 43%; difference 9.2%, 95% CI 3.0-15%; p < 0.01).

CONCLUSIONS

Risk-adapted US-directed and MRI-directed pathways detected GG ≥2 cancers equally well. The risk-adapted US-directed pathway performs well for prostate cancer diagnosis if prostate MRI capacity and expertise are not available. If prostate MRI availability is sufficient, risk assessment should preferably be performed using MRI, as this avoids more biopsies and detects fewer cases of GG 1 cancer.

PATIENT SUMMARY

Among men with suspected prostate cancer, relevant cancers were equally well detected by risk-based pathways using either ultrasound or magnetic resonance imaging (MRI) to guide biopsy of the prostate. If prostate MRI availability is sufficient, risk assessment should be performed with MRI to reduce unnecessary biopsies and detect fewer irrelevant cancers.

Assessment of free-hand transperineal targeted prostate biopsy using multiparametric magnetic resonance imaging-transrectal ultrasound fusion in Chinese men with prior negative biopsy and elevated prostate-specific antigen

BACKGROUND

To evaluate the role of free-hand transperineal targeted prostate biopsy using multiparametric magnetic resonance imaging-transrectal ultrasound (mpMRI-TRUS) fusion in Chinese men with repeated biopsy.

METHODS

A total of 101 consecutive patients suspicious of prostate cancer (PCa) at the mpMRI scan and with prior negative biopsy and elevated PSA values were prospectively recruited at two urological centers. Suspicious areas on mpMRI were defined and graded using PI-RADS score. Targeted biopsies (TB) were performed for each suspicious lesion and followed a 12-core systematic biopsy (SB). Results of biopsy pathology and whole-gland pathology at prostatectomy were analyzed and compared between TB and SB. The risk for biopsy positivity was assessed by univariate and multivariate logistic regression analysis.

RESULTS

Fusion biopsy revealed PCa in 41 of 101 men (40.6%) and 25 (24.8%) were clinically significant. There was exact agreement between TB and SB in 74 (73.3%) men. TB diagnosed 36% more significant cancer than SB (22 vs 13 cases, P = 0.012). When TB were combined with SB, an additional 14 cases (34.1%) of mostly significant PCa (71.4%) were diagnosed (P = 0.036). TB had greater sensitivity and accuracy for significant cancer than SB in 26 men with whole-gland pathology after prostatectomy. PI-RADS score on mpMRI was the most powerful predictor of PCa and significant cancer.

CONCLUSIONS

Free-hand transperineal TB guided with MRI-TRUS fusion imaging improves detection of clinical significant PCa in Chinese men with previously negative biopsy. PI-RADS score is a reliable predictor of PCa and significant cancer.

A deep learning method for real-time intraoperative US image segmentation in prostate brachytherapy

PURPOSE

This paper addresses the detection of the clinical target volume (CTV) in transrectal ultrasound (TRUS) image-guided intraoperative for permanent prostate brachytherapy. Developing a robust and automatic method to detect the CTV on intraoperative TRUS images is clinically important to have faster and reproducible interventions that can benefit both the clinical workflow and patient health.

METHODS

We present a multi-task deep learning method for an automatic prostate CTV boundary detection in intraoperative TRUS images by leveraging both the low-level and high-level (prior shape) information. Our method includes a channel-wise feature calibration strategy for low-level feature extraction and learning-based prior knowledge modeling for prostate CTV shape reconstruction. It employs CTV shape reconstruction from automatically sampled boundary surface coordinates (pseudo-landmarks) to detect the low-contrast and noisy regions across the prostate boundary, while being less biased from shadowing, inherent speckles, and artifact signals from the needle and implanted radioactive seeds.

RESULTS

The proposed method was evaluated on a clinical database of 145 patients who underwent permanent prostate brachytherapy under TRUS guidance. Our method achieved a mean accuracy of [Formula: see text] and a mean surface distance error of [Formula: see text]. Extensive ablation and comparison studies show that our method outperformed previous deep learning-based methods by more than 7% for the Dice similarity coefficient and 6.9 mm reduced 3D Hausdorff distance error.

CONCLUSION

Our study demonstrates the potential of shape model-based deep learning methods for an efficient and accurate CTV segmentation in an ultrasound-guided intervention. Moreover, learning both low-level features and prior shape knowledge with channel-wise feature calibration can significantly improve the performance of deep learning methods in medical image segmentation.

A direct comparison of contrast-enhanced ultrasound and dynamic contrast-enhanced magnetic resonance imaging for prostate cancer detection and prediction of aggressiveness

INTRODUCTION

Dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) and contrast-enhanced ultrasound (CEUS) analyse tissue vascularization. We evaluated if CEUS can provide comparable information as DCE-MRI for the detection of prostate cancer (PCa) and prediction of its aggressiveness.

MATERIAL AND METHODS

A post-hoc evaluation of 92 patients was performed. In each patient CEUS and DCE-MRI parameters of the most suspicious lesion identified on MRI were analysed. The predictive values for discrimination between benign lesions, low-/intermediate- and high-grade PCa were evaluated. Results of targeted biopsy served as reference standard (benign lesions, n=51; low- and intermediate-grade PCa [Gleason grade group 1 and 2], n=22; high-grade PCa [≥ Gleason grade group 3], n=19).

RESULTS

In peripheral zone lesions of all tested CEUS parameters only time to peak (TTP_CEUS) showed significant differences between benign lesions and PCa (AUC 0.65). Of all tested DCE-MRI parameters, rate constant (K_ep) was the best discriminator of high-grade PCa in the whole prostate (AUC 0.83) and in peripheral zone lesions (AUC 0.89).

CONCLUSION

DCE-MRI showed a superior performance for detection of PCa and prediction of its aggressiveness. CEUS and DCE-MRI performed better in peripheral zone lesions than in transition zone lesions.

KEY POINTS

• DCE-MRI gathers information about vascularization and capillary permeability characteristics of tissues. • DCE-MRI can detect PCa and predict its aggressiveness. • CEUS also gathers information about vascularization of tissues. • For detection of PCa and prediction of aggressiveness DCE-MRI performed superiorly. • Both imaging techniques performed better in peripheral zone lesions.

Significance of MRI/Transrectal Ultrasound Fusion Three-Dimensional Model-Guided, Targeted Biopsy Based on Transrectal Ultrasound-Guided Systematic Biopsy in Prostate Cancer Detection: A Systematic Review and Meta-Analysis

PURPOSE

To assess MRI/Transrectal Ultrasound (TRUS) fusion three-dimensional model-guided targeted biopsy (3D-Tb) versus TRUS-guided systematic biopsy (Sb) in detecting overall and high-Gleason-score (≥7) prostate cancer (PCa).

METHODS

Pubmed and Web of science were searched. Studies with men having a suspicious lesion on MRI were included, which were divided into initial biopsy, previous negative biopsy, and mixed groups in meta-analysis.

RESULTS

Totally 13 cohorts in 12 studies, with 3,225 men were included. In total population, 3D-Tb and Sb did not differ significantly in the PCa detection rate (43.1 vs. 42.6%, p = 0.36), but after excluding initial biopsy group, the superiority of 3D-Tb became significant (p = 0.01); 3D-Tb had a significantly higher detection rate of high-Gleason-score PCa compared to Sb (30.0 vs. 24.1%, p < 0.05); 3D-Tb plus Sb significantly improved the PCa detection rate based on Sb alone (52.7 vs. 42.6%, p < 0.05).

CONCLUSIONS

In men with increased serum PSA and/or abnormal DRE and suspicious lesion on MRI but non-previous evidence of PCa, 3D-Tb plus Sb improves the PCa detection rate based on Sb alone. 3D-Tb alone has better performance in detecting high-Gleason-score PCa, and tends to have a higher PCa detection rate in population with previous negative biopsy compared to Sb.

Image-based monitoring of targeted biopsy-proven prostate cancer on active surveillance: 11-year experience

PURPOSE

To report our 11-year experience of Active Surveillance (AS) program focusing on modern transrectal ultrasound (TRUS)-based monitoring of targeted biopsy-proven cancer lesion.

METHODS

Consecutive patients on AS, who had targeted biopsy-proven lesion followed by at least a repeat surveillance biopsy and three times TRUS monitoring of the identical visible lesion, were included. Doppler grade of blood flow signal within the lesion was classified from grade 0 to 3. Biopsy-proven progression was defined as upgrade of Gleason score or 25% or greater increase in cancer core involvement.

RESULTS

Fifty patients were included in this study. Clinical variables (median) included age (61 years), clinical stage (T1c, 42;T2, 8), PSA (4.6 ng/ml), and Gleason score (3 + 3, n = 41;3 + 4, n = 9). Of the 50 patients, 34 demonstrated pathological progression at a median follow-up of 4.4 years. In comparing between without (n = 16) and with (n = 34) pathological progression, there were significant differences in cancer core involvement at entry (p = 0.003), the major axis diameter (p = 0.001) and minor axis diameter (p = 0.001) of the visible lesion at entry, increase in the major axis diameter (p = 0.005) and minor axis diameter (p = 0.013), and upgrade of Doppler grade (p < 0.0001). In multivariate analysis for predicting pathological progression, the increase (≥25%) in diameter of biopsy-proven lesion (hazard ratio, 15.314; p = 0.023) and upgrade of Doppler grade (hazard ratio, 37.409; p = 0.019) were significant risk factors.

CONCLUSIONS

Longitudinal monitoring of the TRUS-visible biopsy-proven cancer provides a new opportunity to perform per-lesion-based AS. The increase in diameter and upgrade of Doppler grade of the lesion were significant risk factors for biopsy-proven progression on AS.

The evolving role of contrast-enhanced ultrasound in urology: a review

PURPOSE

Ultrasound's versatility and ease of use has expanded its application in many clinical settings. Technological advancements with contrast-enhanced ultrasound (CEUS) have allowed high quality imaging similar to CT or MRI with lower risk of contrast toxicity and radiation exposure. In this review article we examine the development of CEUS and its vast applications in the field of urology.

METHODS

A PubMed literature search was performed using keywords: contrast enhanced ultrasound, prostate cancer, renal cancer, and multiparametric ultrasound.

RESULTS

The development of CEUS has improved transrectal ultrasound imaging with increased detection of prostate cancer (PCa). Further enhancements of CEUS such as subharmonic imaging (SHI), flash replenishment imaging (FRI) and contrast ultrasound dispersion imaging (CUDI) allow improved PCa diagnosis. CEUS has also emerged as an important tool in characterizing suspicious renal mass without compromising renal function with contrast imaging.

CONCLUSION

CEUS has modernized imaging and diagnosis of prostate and renal cancer. Future advancements and utilization of CEUS will allow its expansion into other urological subspecialties.

New imaging modalities to consider for men with prostate cancer on active surveillance

PURPOSE

To discuss the potential utility of newer imaging modalities including micro-ultrasound and PSMA-PET for the detection of clinically significant prostate cancer, technologies that may gain roles as adjuncts to multiparametric magnetic resonance imaging (mpMRI) in the active surveillance (AS) setting.

METHODS

Narrative review of two new imaging modalities used for primary prostate cancer through April 2021. A targeted search was performed to identify current relevant literature on the role of new imaging modalities for primary prostate cancer using search terms "micro-ultrasound," "molecular imaging," "prostate cancer," "active surveillance," "multiparametric MRI," "PI-RADS," "PRI-MUS," and "detection rate." In addition, references of included articles were screened for further relevant publications.

RESULTS

Micro-ultrasound (micro-US) and prostate-specific membrane antigen-positron emission tomography (PSMA-PET) are increasing in their use and applicability to prostate cancer imaging. Micro-US is used for cancer detection and may identify higher grade cancers more accurately than conventional ultrasound, despite technical hurdles in its initial launch. PSMA-PET is highly sensitive and specific for high-grade and metastatic prostate cancer, though costly and not easily available. Though data are sparse, it may have an emerging role in cancer diagnosis in select localized cases, and in some men considering (or currently on) AS who have indications of more aggressive disease.

CONCLUSION

There are very limited data on micro-US and PSMA-PET in AS patients. However, given the ability of these modalities to identify high-grade cancer, their judicious use in AS patients may be of utility in the future.

Domain generalization for prostate segmentation in transrectal ultrasound images: A multi-center study

Prostate biopsy and image-guided treatment procedures are often performed under the guidance of ultrasound fused with magnetic resonance images (MRI). Accurate image fusion relies on accurate segmentation of the prostate on ultrasound images. Yet, the reduced signal-to-noise ratio and artifacts (e.g., speckle and shadowing) in ultrasound images limit the performance of automated prostate segmentation techniques and generalizing these methods to new image domains is inherently difficult. In this study, we address these challenges by introducing a novel 2.5D deep neural network for prostate segmentation on ultrasound images. Our approach addresses the limitations of transfer learning and finetuning methods (i.e., drop in performance on the original training data when the model weights are updated) by combining a supervised domain adaptation technique and a knowledge distillation loss. The knowledge distillation loss allows the preservation of previously learned knowledge and reduces the performance drop after model finetuning on new datasets. Furthermore, our approach relies on an attention module that considers model feature positioning information to improve the segmentation accuracy. We trained our model on 764 subjects from one institution and finetuned our model using only ten subjects from subsequent institutions. We analyzed the performance of our method on three large datasets encompassing 2067 subjects from three different institutions. Our method achieved an average Dice Similarity Coefficient (Dice) of 94.0±0.03 and Hausdorff Distance (HD95) of 2.28 mm in an independent set of subjects from the first institution. Moreover, our model generalized well in the studies from the other two institutions (Dice: 91.0±0.03; HD95: 3.7 mm and Dice: 82.0±0.03; HD95: 7.1 mm). We introduced an approach that successfully segmented the prostate on ultrasound images in a multi-center study, suggesting its clinical potential to facilitate the accurate fusion of ultrasound and MRI images to drive biopsy and image-guided treatments.

Etiology, Diagnosis, and Management of Seminal Vesicle Stones

Background/Aims

Seminal vesicle (SV) stones are a rare, and thus readily misdiagnosed condition in practice. Understanding the etiology, diagnosis, and management are crucial to guide a urologist's care, and are provided in this literature review.

Methods

The inclusion criteria for the literature search, using the search engines MEDLINE® and PubMed was conducted using a combined query of "seminal vesicle stone" and the following keywords: calculi, hematospermia, calcification, and transrectal ultrasound (TRUS).

Results

The etiology of SV stones is currently unknown where majority of the patients present with having painful ejaculation and hematospermia. However, clinicians have reported potential etiologies by categorization as an inflammatory or non-in-flammatory. A majority of the previous cases had shown multiple stones being present in the SV duct system that are typically diagnosed through radiological examination such as TRUS, MRI, or plain radiographs. Amongst the many imaging approaches, TRUS remains the primary imaging diagnoses of SV calculi. Transurethral seminal vesiculoscopy has shown to be used in an abundant of the case reports to be an ideal surgical approach for managing small SV stones. In regard to larger stones, a transperitoneal laparoscopic protocol is proper.

Conclusion

The current imaging techniques have increased the case reports and diagnosis of SV calculi; however, more research is warranted for understanding the pathogenesis of the formation of SV stones. An optimal management of the extraction of SV stones depends on a number of factors such as size and location.