How Accurately Can Prostate Gland Imaging Measure the Prostate Gland Volume? Results of a Systematic Review

Challenges in Using Deep Neural Networks Across Multiple Readers in Delineating Prostate Gland Anatomy

Deep learning methods provide enormous promise in automating manually intense tasks such as medical image segmentation and provide workflow assistance to clinical experts. Deep neural networks (DNN) require a significant amount of training examples and a variety of expert opinions to capture the nuances and the context, a challenging proposition in oncological studies (H. Wang et al., Nature, vol. 620, no. 7972, pp. 47-60, Aug 2023). Inter-reader variability among clinical experts is a real-world problem that severely impacts the generalization of DNN reproducibility. This study proposes quantifying the variability in DNN performance using expert opinions and exploring strategies to train the network and adapt between expert opinions. We address the inter-reader variability problem in the context of prostate gland segmentation using a well-studied DNN, the 3D U-Net model. Reference data includes magnetic resonance imaging (MRI, T2-weighted) with prostate glandular anatomy annotations from two expert readers (R#1, n = 342 and R#2, n = 204). 3D U-Net was trained and tested with individual expert examples (R#1 and R#2) and had an average Dice coefficient of 0.825 (CI, [0.81 0.84]) and 0.85 (CI, [0.82 0.88]), respectively. Combined training with a representative cohort proportion (R#1, n = 100 and R#2, n = 150) yielded enhanced model reproducibility across readers, achieving an average test Dice coefficient of 0.863 (CI, [0.85 0.87]) for R#1 and 0.869 (CI, [0.87 0.88]) for R#2. We re-evaluated the model performance across the gland volumes (large, small) and found improved performance for large gland size with an average Dice coefficient to be at 0.846 [CI, 0.82 0.87] and 0.872 [CI, 0.86 0.89] for R#1 and R#2, respectively, estimated using fivefold cross-validation. Performance for small gland sizes diminished with average Dice of 0.8 [0.79, 0.82] and 0.8 [0.79, 0.83] for R#1 and R#2, respectively.

Goldstandard TUR-P: the bigger the volume, the higher the speed, but resected volumes of more than 60g are critical

BACKGROUND

According to the European Association of Urology guidelines, the limit for monopolar, transurethral resection (M-TURP) in BPH- therapy is a volume of 80 g. However, whether larger prostates can also be resected transurethrally might also depend on the experience of the surgeon and especially the resected volume and speed of the resection. Little is known about the latter, and this paper aims to these factors.

METHODS

This study included 540 patients who received a single-stage M-TURP. Based on the postoperative resection weight, these were divided into four groups: group 1 with 10 to 59.9 g, group 2 with 60 to 79.9 g, group 3 with 80 to 99.9 g, and group 4 with ≥ 100 g. We examined patient age, the ASA-score, the IPSS, quality of life, resection weight, time and speed, pre- and postoperative hemoglobin and serum sodium values, complications, and surgeon experience.

RESULTS

The mean resection weight was 41.6 g, and the mean values for resection time and speed were 61.3 min and 0.7 g/min, respectively. The resection speed increased significantly with resection weight (from 0.7 to 1.3 g/min) as well as with the surgeon's level of experience (from 0.4 to 0.9 g/min). The number of serious complications (Clavien-Dindo ≥ IIIb) increased significantly from a resection volume of 59.5 g (cut-off value). The resection speed of M-TURP increased significantly with the resection weight and the surgeon's level of experience. Regardless of speed, resection weight of more than 60 g might increase the risk of severe complications.

MRI-Derived Transition Zone Index Is Highly Predictive of Urodynamic Bladder Outlet Obstruction Prior to Holmium Laser Enucleation of the Prostate

INTRODUCTION AND OBJECTIVE

Urodynamic study (UDS) is required to diagnose bladder outlet obstruction (BOO) during evaluation of benign prostatic hyperplasia (BPH) but is seldom performed due to cost and invasiveness. Therefore, anatomic and clinical parameters to predict BOO have been proposed, including the prostate transition zone index (TZI) which is the ratio of prostate transition zone volume (TZV) to whole gland volume (WGV). Historically computed with ellipsoid volume estimation of prostate WGV and TZV from transrectal ultrasound measurements, controversy exists regarding the utility of TZI to predict likelihood of BOO on UDS and clinical outcomes following BPH surgery. Here, we aim to assess the association between MRI-measured TZI and BOO on preoperative UDS in a modern BPH cohort before holmium laser enucleation of the prostate (HoLEP).

METHODS

A prospectively maintained institutional database of 944 consecutive HoLEP patients between 2018 and 2022 was reviewed to identify those with preoperative UDS and MRI within 1 year of surgery. UDS was used to measure bladder outlet obstruction index (BOOI). 3D WGV and TZV were estimated using clinically available software (DynaCAD). We used linear regression to assess the relationship between TZI, WGV, and BOOI and logistic regression to determine the association between TZI, WGV, and BOO (defined as BOOI > 40).

RESULTS

45/944 (4.8%) patients had both preoperative UDS and MRI within 1 year of HoLEP. Of these, 27 patients were obstructed (BOOI > 40) and 18 patients were not obstructed (BOOI ≤ 40) on preoperative UDS. Obstructed patients had larger prostate WGV, TZV, and TZI compared to non-obstructed patients but were otherwise similar with respect to preoperative characteristics. Univariate analysis showed a positive association between TZI and BOO (R2 = 0.373, p < 0.001) and WGV and BOO (R2 = 0.214, p < 0.001). Multivariable logistic regression showed that TZI was independently associated with BOO (OR 1.08, 95% CI 1.02-1.14, p = 0.013) while accounting for WGV. WGV was not independently associated with BOO while accounting for TZI (OR 1.00, 95% CI 0.98-1.01, p = 0.614). The Youden index was utilized to create an optimal cutpoint for TZI (0.528) above which urodynamic BOO was very likely on multivariate logistic regression while accounting for WGV (OR 25.0, 95% CI 3.40-183.58, p = 0.002). The generated cutpoint for WGV (61.5 mL) was not significantly associated with urodynamic BOO on multivariate logistic regression while accounting for TZI (OR 0.993, 95% CI 0.98-1.01, p = 0.452).

CONCLUSIONS

Noninvasive MRI measurement of prostate TZI was highly and independently predictive of BOO before HoLEP and superior to WGV alone. This suggests that MRI obtained in evaluation of BPH/LUTS patients may be used to calculate TZI and inform patient selection for invasive urodynamic study and surgical treatment.

Achieving accurate prostate auto-segmentation on CT in the absence of MR imaging

BACKGROUND

Magnetic resonance imaging (MRI) is considered the gold standard for prostate segmentation. Computed tomography (CT)-based segmentation is prone to observer bias, potentially overestimating the prostate volume by ∼ 30 % compared to MRI. However, MRI accessibility is challenging for patients with contraindications or in rural areas globally with limited clinical resources.

PURPOSE

This study investigates the possibility of achieving MRI-level prostate auto-segmentation accuracy using CT-only input via a deep learning (DL) model trained with CT-MRI registered segmentation.

METHODS AND MATERIALS

A cohort of 111 definitive prostate radiotherapy patients with both CT and MRI images was retrospectively grouped into training (n = 37) and validation (n = 20) (where reference contours were derived from CT-MRI registration), and testing (n = 54) sets. Two commercial DL models were benchmarked against the reference contours in the training and validation sets. A custom DL model was incrementally retrained using the training dataset, quantitatively evaluated on the validation dataset, and qualitatively assessed by two different physician groups on the validation and testing datasets. A contour quality assurance (QA) model, established from the proposed model on the validation dataset, was applied to the test group to identify potential errors, confirmed by human visual inspection.

RESULTS

Two commercial models exhibited large deviations in the prostate apex with CT-only input (median: 0.77/0.78 for Dice similarity coefficient (DSC), and 0.80 cm/0.83 cm for 95 % directed Hausdorff Distance (HD95), respectively). The proposed model demonstrated superior geometric similarity compared to commercial models, particularly in the apex region, with improvements of 0.05/0.17 cm and 0.06/0.25 cm in median DSC/HD95, respectively. Physician evaluation on MRI-CT registration data rated 69 %-78 % of the proposed model's contours as clinically acceptable without modifications. Additionally, 73 % of cases flagged by the contour quality assurance (QA) model were confirmed via visual inspection.

CONCLUSIONS

The proposed incremental learning strategy based on CT-MRI registration information enhances prostate segmentation accuracy when MRI availability is limited clinically.

Surface-Based Ultrasound Scans for the Screening of Prostate Cancer

Surface-based ultrasound (SUS) systems have undergone substantial improvement over the years in image quality, ease-of-use, and reduction in size. Their ability to image organs non-invasively makes them a prime technology for the diagnosis and monitoring of various diseases and conditions. An example is the screening/risk- stratification of prostate cancer (PCa) using prostate-specific antigen density (PSAD). Current literature predominantly focuses on prostate volume (PV) estimation techniques that make use of magnetic resonance imaging (MRI) or transrectal ultrasound (TRUS) imaging, while SUS techniques are largely overlooked. If a reliable SUS PCa screening method can be introduced, patients may be able to forgo unnecessary MRI or TRUS scans. Such a screening procedure could be introduced into standard primary care settings with point-of-care ultrasound systems available at a fraction of the cost of their larger hospital counterparts. This review analyses whether literature suggests it is possible to use SUS-derived PV in the calculation of PSAD.

Transrectal versus transperineal prostate biopsy for cancer detection in patients with gray-zone prostate-specific antigen: a multicenter, real-world study

Knowledge about the effect of different prostate biopsy approaches on the prostate cancer detection rate (CDR) in patients with gray-zone prostate-specific antigen (PSA) is limited. We performed this study to compare the CDR among patients who underwent different biopsy approaches and had rising PSA levels in the gray zone. Two hundred and twenty-two patients who underwent transrectal prostate biopsy (TRB) and 216 patients who underwent transperineal prostate biopsy (TPB) between June 2016 and September 2022 were reviewed in this study. In addition, 110 patients who received additional targeted biopsies following the systematic TPB were identified. Clinical parameters, including age, PSA derivative, prostate volume (PV), and needle core count, were recorded. The data were fitted via propensity score matching (PSM), adjusting for potential confounders. TPB outperformed TRB in terms of the CDR (49.6% vs 28.3%, P = 0.001). The clinically significant prostate cancer (csPCa) detection rate was not significantly different between TPB and TRB (78.6% vs 68.8%, P = 0.306). In stratified analysis, TPB outperformed TRB in CDR when the age of patients was 65-75 years (59.0% vs 22.0%, P < 0.001), when PV was 25.00-50.00 ml (63.2% vs 28.3%, P < 0.001), and when needle core count was no more than 12 (58.5% vs 31.5%, P = 0.005). The CDR ( P = 0.712) and detection rate of csPCa ( P = 0.993) did not significantly differ among the systematic, targeted, and combined biopsies. TPB outperformed TRB in CDR for patients with gray-zone PSA. Moreover, performing target biopsy after systematic TPB provided no additional benefits in CDR.

Polygenic risk score predicting susceptibility and outcome of benign prostatic hyperplasia in the Han Chinese

BACKGROUND

Given the high prevalence of BPH among elderly men, pinpointing those at elevated risk can aid in early intervention and effective management. This study aimed to explore that polygenic risk score (PRS) is effective in predicting benign prostatic hyperplasia (BPH) incidence, prognosis and risk of operation in Han Chinese.

METHODS

A retrospective cohort study included 12,474 male participants (6,237 with BPH and 6,237 non-BPH controls) from the Taiwan Precision Medicine Initiative (TPMI). Genotyping was performed using the Affymetrix Genome-Wide TWB 2.0 SNP Array. PRS was calculated using PGS001865, comprising 1,712 single nucleotide polymorphisms. Logistic regression models assessed the association between PRS and BPH incidence, adjusting for age and prostate-specific antigen (PSA) levels. The study also examined the relationship between PSA, prostate volume, and response to 5-α-reductase inhibitor (5ARI) treatment, as well as the association between PRS and the risk of TURP.

RESULTS

Individuals in the highest PRS quartile (Q4) had a significantly higher risk of BPH compared to the lowest quartile (Q1) (OR = 1.51, 95% CI = 1.274-1.783, p < 0.0001), after adjusting for PSA level. The Q4 group exhibited larger prostate volumes and a smaller volume reduction after 5ARI treatment. The Q1 group had a lower cumulative TURP probability at 3, 5, and 10 years compared to the Q4 group. PRS Q4 was an independent risk factor for TURP.

CONCLUSIONS

In this Han Chinese cohort, higher PRS was associated with an increased susceptibility to BPH, larger prostate volumes, poorer response to 5ARI treatment, and a higher risk of TURP. Larger prospective studies with longer follow-up are warranted to further validate these findings.

The Role of Digital Rectal Examination Prostate Volume Category in the Early Detection of Prostate Cancer: Its Correlation with the Magnetic Resonance Imaging Prostate Volume

PURPOSE

To relate the prostate volume category (PVC) assessed with digital rectal examination (DRE)-small, median, and large-and the prostate volumes (PVs) assessed with magnetic resonance imaging (MRI) and transrectal ultrasound (TRUS). To compare the clinically significant prostate cancer (csPCa) discrimination ability of two predictive models based on DRE-PVC and MRI-PV.

MATERIALS AND METHODS

A prospective trial of 2,090 men with prostate-specific antigen >3 ng/mL and/or PCa suspicious DRE were prospectively recruited in 10 centers from Catalonia (Spain), between 2021 and 2022, in whom DRE-PVC was assessed. Pre-biopsy MRI, and 12-core TRUS-random biopsy was always performed after 2- to 6-core TRUS-fusion targeted biopsy of prostate imaging-report and data system >3 lesions. In 370 men (17.7%) the DRE-PVC was unconclusive. Among the 1,720 men finally analyzed the csPCa (grade group >2) detection was 42.4%.

RESULTS

The median (interquartile range) of TRUS and MRI-PVs of small prostates were 33 mL (19-37 mL) and 35 mL (23-30 mL), p=0.410; in median prostates they were 51 mL (38-58 mL) and 55 mL (48-63 mL) respectively, p<0.001; in large prostates 80 mL (60-100 mL) and 95 mL (75-118 mL) respectively, p<0.001. The predictive models sharing the MRI-PV and DRE-PVC showed areas under the curves of 0.832 (95% confidence interval [CI], 0.813-0.851) and 0.828 (95% CI, 0.809-0.848) respectively, p=0.632, as well as similar net benefit and clinical utility.

CONCLUSIONS

PVC was unconclusive in 17% of DREs. MRI-PV overestimated the TRUS-PV in median and large prostates. The predictive models based on MRI-PV and DRE-PVC showed similar efficacy to predict csPCa. PVC assessed with DRE is helpful to predict the csPCa risk before MRI.

Exploration of the diagnostic capacity of PSAMR combined with PI-RADS scoring for clinically significant prostate cancer and establishment and validation of the Nomogram prediction model

PURPOSE

The objective of this investigation was to explore the diagnostic capability of Prostate Specific Antigen Mass Ratio (PSAMR) combined with Prostate Imaging Reporting and Data System (PI-RADS) scoring for clinically significant prostate cancer (CSPC), develop and validate a Nomogram prediction model for the probability of prostate cancer occurrence in patients who have not undergone prostate biopsy.

METHODS

Initially, we retrospectively collected clinical and pathological data of patients who underwent trans-perineal prostate puncture at Yijishan Hospital of Wanan Medical College from July 2021 to January 2023. Through logistic univariate and multivariate regression analysis, independent risk factors for CSPC were determined. Receiver Operating Characteristic (ROC) curves were generated to compare the ability of different factors for diagnosis of CSPC. Then, we split the dataset into a training set and validation set, compared their heterogeneity, and developed a Nomogram prediction model based on the training set. Finally, we validated the Nomogram prediction model in terms of discrimination, calibration, and clinical usefulness.

RESULTS

Logistic multivariate regression analysis illustrated that age [64-69 (OR = 2.736, P = 0.029); 69-75 (OR = 4.728, P = 0.001); > 75 (OR = 11.344, P < 0.001)], PSAMR [0.44-0.73 (OR = 4.144, P = 0.028); 0.73-1.64(OR = 13.022, P < 0.001); > 1.64(OR = 50.541, P < 0.001)], and PI-RADS score [4 points (OR = 7.780, P < 0.001); 5 points (OR = 24.533, P < 0.001)] were independent risk factors for CSPC. The Area Under the Curve (AUC) of the ROC curves of PSA, PSAMR, PI-RADS score, and PSAMR combined with PI-RADS score were respectively 0.797, 0.874, 0.889, and 0.928. The performance of PSAMR and PI-RADS score for diagnosis of CSPC was superior to PSA, but inferior to PSAMR combined with PI-RADS. Age, PSAMR, and PI-RADS were included in the Nomogram prediction model. The AUCs of the training set ROC curve and the validation set ROC curve were 0.943 (95% CI 0.917-0.970) and 0.878 (95% CI 0.816-0.940), respectively, in the discrimination validation. The calibration curve showed good consistency, and the decision analysis curve suggested the model had good clinical efficacy.

CONCLUSIONS

We found that PSAMR combined with PI-RADS scoring had a strong diagnostic capability for CSPC, and provided a Nomogram prediction model to predict the probability of prostate cancer occurrence combined with clinical data.

Comparison of prostate volume measured by transabdominal ultrasound and MRI with the radical prostatectomy specimen volume: a retrospective observational study

BACKGROUND

Few studies have compared the use of transabdominal ultrasound (TAUS) and magnetic resonance imaging (MRI) to measure prostate volume (PV). In this study, we evaluate the accuracy and reliability of PV measured by TAUS and MRI.

METHODS

A total of 106 patients who underwent TAUS and MRI prior to radical prostatectomy were retrospectively analyzed. The TAUS-based and MRI-based PV were calculated using the ellipsoid formula. The specimen volume measured by the water-displacement method was used as a reference standard. Correlation analysis and intraclass correlation coefficients (ICC) were performed to compare different measurement methods and Bland Altman plots were drawn to assess the agreement.

RESULTS

There was a high degree of correlation and agreement between the specimen volume and PV measured with TAUS (r = 0.838, p < 0.01; ICC = 0.83) and MRI (r = 0.914, p < 0.01; ICC = 0.90). TAUS overestimated specimen volume by 2.4ml, but the difference was independent of specimen volume (p = 0.19). MRI underestimated specimen volume by 1.7ml, the direction and magnitude of the difference varied with specimen volume (p < 0.01). The percentage error of PV measured by TAUS and MRI was within ± 20% in 65/106(61%) and 87/106(82%), respectively. In patients with PV greater than 50 ml, MRI volume still correlated strongly with specimen volume (r = 0.837, p < 0.01), while TAUS volume showed only moderate correlation with specimen (r = 0.665, p < 0.01) or MRI volume (r = 0.678, p < 0.01).

CONCLUSIONS

This study demonstrated that PV measured by MRI and TAUS is highly correlated and reliable with the specimen volume. MRI might be a more appropriate choice for measuring the large prostate.

Prostate gland volume estimation: anteroposterior diameters measured on axial versus sagittal ultrasonography and magnetic resonance images

PURPOSE

The aim of this study was to evaluate the accuracy of prostate volume estimates calculated from the ellipsoid formula using the anteroposterior (AP) diameter measured on axial and sagittal images obtained through ultrasonography (US) and magnetic resonance imaging (MRI).

METHODS

This retrospective study included 456 patients with transrectal US and MRI from two university hospitals. Two radiologists independently measured the prostate gland diameters on US and MRI: AP diameters on axial and sagittal images, transverse, and longitudinal diameters on midsagittal images. The volume estimates, volumeax and volumesag, were calculated from the ellipsoid formula by using the AP diameter on axial and sagittal images, respectively. The prostate volume extracted from MRI-based whole-gland segmentation was considered the gold standard. The intraclass correlation coefficient (ICC) was used to evaluate the inter-method agreement between volumeax and volumesag, and agreement with the gold standard. The Wilcoxon signedrank test was used to analyze the differences between the volume estimates and the gold standard.

RESULTS

The prostate gland volume estimates showed excellent inter-method agreement, and excellent agreement with the gold standard (ICCs >0.9). Compared with the gold standard, the volume estimates were significantly larger on MRI and significantly smaller on US (P<0.001). The volume difference (segmented volume-volume estimate) was greater in patients with larger prostate glands, especially on US.

CONCLUSION

Volumeax and volumesag showed excellent inter-method agreement and excellent agreement with the gold standard on both US and MRI. However, prostate volume was overestimated on MRI and underestimated on US.

Correlation of Postoperative Outcomes According to the Amount of Prostatic Tissue Removed in Patients Undergoing Transurethral Resection of the Prostate

OBJECTIVE

The present study assesses the effect of the proportion of tissue resected during transurethral resections of the prostate (TUR-P) on lower urinary tract symptoms (LUTS) and other parameters in patients with a benign prostatic obstruction (BPO).

MATERIALS AND METHODS

Forty-three patients who underwent TUR-P between 2018 and 2021 were assessed prospectively. The patients were divided into two groups according to the percentage of tissue removed (group 1 <30%, group 2 >30% resection). Age, prostate volume, amount of resected tissue, operative time, length of hospital stay, duration of catheterization, International Prostate Symptom Score (IPSS), quality of life score (QoL), maximum urinary flow rate (Qmax), and serum prostate-specific antigen (PSA) (ng/dl) at preoperative and postoperative three months were recorded.

RESULTS

The percentage of tissue removed was 22.2% vs. 48.4% (p = 0.001), IPSS reduction was 77.7% vs. 83.3% (p = 0.048), QoL improvement was 77.2% vs. 84.8% (p = 0.133), Qmax increase was 171.3% vs. 193.5% (p = 0.032), and serum PSA decrease was 56.4% vs. 69.2% (p = 0.049) in groups 1 and 2, respectively. In addition, the operative time was 38.5 vs. 53.6 min (p = 0.001), the length of hospital stay was 2.0 vs. 2.4 days (p = 0.001), and the duration of catheterization average was 4.1 vs. 4.9 days (p = 0.002).

CONCLUSION

Resections of at least 30% of prostatic tissue can provide a significant improvement in the symptoms and parameters related to benign prostatic obstruction, while resections of less than 30% of prostatic tissue can effectively reduce urinary symptoms and improve the quality of life in older adult patients with comorbidities who require shorter operating times.

Diagnostic Accuracy of Predictive Models in Prostate Cancer: A Systematic Review and Meta-Analysis

Aim

Accurate diagnosis of prostate cancer (PCa) has a fundamental role in clinical and patient care. Recent advances in diagnostic testing and marker lead to standardized interpretation and increased prescription by clinicians to improve the detection of clinically significant PCa and select patients who strictly require targeted biopsies.

Methods

In this study, we present a systematic review of the overall diagnostic accuracy of each testing panel regarding the panel details. In this meta-analysis, using a structured search, Web of Science and PubMed databases were searched up to 23 September 2019 with no restrictions and filters. The study's outcome was the AUC and 95% confidence interval of prediction models. This index was reported as an overall and based on the WHO region and models with/without MRI.

Results

The thirteen final articles included 25,691 people. The overall AUC and 95% CI in thirteen studies were 0.78 and 95% CI: 0.73-0.82. The weighted average AUC in the countries of the Americas region was 0.73 (95% CI: 0.70-0.75), and in European countries, it was 0.80 (95% CI: 0.72-0.88). In four studies with MRI, the average weighted AUC was 0.88 (95% CI: 0.86-0.90), while in other articles where MRI was not a parameter in the diagnostic model, the mean AUC was 0.73 (95% CI: 0.70-0.76).

Conclusions

The present study's findings showed that MRI significantly improved the detection accuracy of prostate cancer and had the highest discrimination to distinguish candidates for biopsy.

AAPM Task Group Report 303 endorsed by the ABS: MRI Implementation in HDR Brachytherapy-Considerations from Simulation to Treatment

The Task Group (TG) on Magnetic Resonance Imaging (MRI) Implementation in High Dose Rate (HDR) Brachytherapy - Considerations from Simulation to Treatment, TG 303, was constituted by the American Association of Physicists in Medicine's (AAPM's) Science Council under the direction of the Therapy Physics Committee, the Brachytherapy Subcommittee, and the Working Group on Brachytherapy Clinical Applications. The TG was charged with developing recommendations for commissioning, clinical implementation, and on-going quality assurance (QA). Additionally, the TG was charged with describing HDR brachytherapy (BT) workflows and evaluating practical consideration that arise when implementing MR imaging. For brevity, the report is focused on the treatment of gynecologic and prostate cancer. The TG report provides an introduction and rationale for MRI implementation in BT, a review of previous publications on topics including available applicators, clinical trials, previously published BT related TG reports, and new image guided recommendations beyond CT based practices. The report describes MRI protocols and methodologies, including recommendations for the clinical implementation and logical considerations for MR imaging for HDR BT. Given the evolution from prescriptive to risk-based QA,¹ an example of a risk-based analysis using MRI-based, prostate HDR BT is presented. In summary, the TG report is intended to provide clear and comprehensive guidelines and recommendations for commissioning, clinical implementation, and QA for MRI-based HDR BT that may be utilized by the medical physics community to streamline this process. This report is endorsed by the American Brachytherapy Society (ABS). This article is protected by copyright. All rights reserved.

A Brief Overview of the Effects of Exercise and Red Beets on the Immune System in Patients with Prostate Cancer

Research over the past few decades has focused on the use of functional ingredients such as an active lifestyle and proper diet as a treatment for many diseases in the world. Recent studies have shown a variety of health benefits for red beets and their active ingredients such as antioxidant, anti-inflammatory, anti-cancer, blood pressure and fat reduction, anti-diabetic, and anti-obesity effects. This review article examines the effects of exercise and red beet consumption and the effective mechanisms of these two interventions on cellular and molecular pathways in prostate cancer. However, there is a significant relationship between an active lifestyle and proper diet with the incidence of cancer, and the use of these natural interventions for cancer patients in the treatment protocol of avoidance patients. Furthermore, this review article attempts to examine the role and effect of exercise and beetroot nutrition on prostate cancer and provide evidence of the appropriate effects of using natural interventions to prevent, reduce, and even treat cancer in stages. In addition, we examine the molecular mechanisms of the effectiveness of exercise and beetroot consumption. Finally, the use of natural interventions such as exercising and eating beets due to their antioxidant, anti-inflammatory, and anti-cancer properties, due to the lack or low level of side effects, can be considered an important intervention for the prevention and treatment of cancer.

Comparative Analysis of PSA Density and an MRI-Based Predictive Model to Improve the Selection of Candidates for Prostate Biopsy

This study is a head-to-head comparison between mPSAD and MRI-PMbdex. The MRI-PMbdex was created from 2432 men with suspected PCa; this cohort comprised the development and external validation cohorts of the Barcelona MRI predictive model. Pre-biopsy 3-Tesla multiparametric MRI (mpMRI) and 2 to 4-core transrectal ultrasound (TRUS)-guided biopsies for suspicious lesions and/or 12-core TRUS systematic biopsies were scheduled. Clinically significant PCa (csPCa), defined as Gleason-based Grade Group 2 or higher, was detected in 934 men (38.4%). The area under the curve was 0.893 (95% confidence interval [CI]: 0.880−0.906) for MRI-PMbdex and 0.764 (95% CI: 0.774−0.783) for mPSAD, with p < 0.001. MRI-PMbdex showed net benefit over biopsy in all men when the probability of csPCa was greater than 2%, while mPSAD did the same when the probability of csPCa was greater than 18%. Thresholds of 13.5% for MRI-PMbdex and 0.628 ng/mL2 for mPSAD had 95% sensitivity for csPCa and presented 51.1% specificity for MRI-PMbdex and 19.6% specificity for mPSAD, with p < 0.001. MRI-PMbdex exhibited net benefit over mPSAD in men with prostate imaging report and data system (PI-RADS) <4, while neither exhibited any benefit in men with PI-RADS 5. Hence, we can conclude that MRI-PMbdex is more accurate than mPSAD for the proper selection of candidates for prostate biopsy among men with suspected PCa, with the exception of men with a PI-RAD S 5 score, for whom neither tool exhibited clinical guidance to determine the need for biopsy.

Transrectal Ultrasound in Prostate Cancer: Current Utilization, Integration with mpMRI, HIFU and Other Emerging Applications

Transrectal ultrasound (TRUS) has been an invaluable tool in the assessment of prostate size, anatomy and aiding in prostate cancer (PCa) diagnosis for decades. Emerging techniques warrant an investigation into the efficacy of TRUS, how it compares to new techniques, and options to increase the accuracy of prostate cancer diagnosis. Currently, TRUS is used to guide both transrectal and transperineal biopsy approaches with similar cancer detection rates, but lower rates of infection have been reported with the transperineal approach, while lower rates of urinary retention are often reported with the transrectal approach. Multiparametric MRI has substantial benefits for prostate cancer diagnosis and triage such as lesion location, grading, and can be combined with TRUS to perform fusion biopsies targeting specific lesions. Micro-ultrasound generates higher resolution images that traditional ultrasound and has been shown effective at diagnosing PCa, giving it the potential to become a future standard of care. Finally, high-intensity focused ultrasound focal therapy administered via TRUS has been shown to offer safe and effective short-term oncological control for localized disease with low morbidity, and the precise nature makes it a viable option for salvage and repeat therapy.

Hemorrhagic cystitis in allogeneic stem cell transplantation: a role for age and prostatic hyperplasia

PURPOSE

Hemorrhagic cystitis (HC) is a frequent complication of allogeneic hematopoietic stem-cell transplantation (HSCT). HC worsens transplant outcomes and patient wellbeing in terms of pain, hospitalization, and need for supportive care. A deeper understanding of the risk factors of HC may lead to more intensive prevention in high-risk patients.

METHODS

In this report, we analyzed 237 consecutive patients who received HSCT with the aim of identifying possible risk factors for HC and their consequences, with a particular focus on transplant- and gender-related risk factors.

RESULTS

HC occurred in 17% of patients, with a higher incidence in males (21% vs 11%, p = 0.03). Risk factors identified for HC included age over 55 years, male recipient, HLA mismatch, reduced intensity conditioning, and cyclophosphamide-based graft-versus-host disease (GVHD) prophylaxis. Increased HC was seen in patients with grade II-IV acute GVHD and detectable BKV and JCV viruria. In a multivariate model, increased age remained significant (p = 0.013). Patients with HC had longer hospitalizations and increased non-relapse mortality (NRM). Among male recipients, independent risk factors for HC included age (p = 0.016) and prostate volume (p = 0.016). Prostatic hyperplasia (volume more than 40 cm³) occurred in 33% of male patients, of which 32% developed HC (compared with 16% of patients without prostatic hyperplasia; p = 0.032).

CONCLUSIONS

Age is the most important risk factor for HC. Additional potential risk factors include cyclophosphamide-based GVHD prophylaxis and HLA mismatch. Among male recipients, prostatic hyperplasia is an additional independent risk factor. As HC is common and associated with prolonged hospitalization, more intensive prophylactic strategies should be considered in high-risk patients.

Evaluating Incidence, Location, and Predictors of Positive Surgical Margin Among Chinese Men Undergoing Robot-Assisted Radical Prostatectomy

Purpose

To evaluate the incidence and locations of positive surgical margin (PSM) among Chinese men undergoing RARP and identify the preoperative predictors for PSM.

Methods

We retrospectively identified 393 patients who underwent RARP according to inclusion criteria by single surgeon in our hospital. PSM was defined as the presence of cancer adjacent to inked surface of the specimen and categorized into four groups based on locations: apex, posterolateral, base, and multifocal. Logistic regression analysis was performed to identify the predictors of overall and location-specific PSM.

Results

The overall PSM rate was 133/393 (34%). The PSM rates for pT2, pT3, and pT4 stage were 63/278 (23%), 50/89 (56%), and 20/26 (77%), respectively. The estimated rates for apical, posterolateral, basal, and multifocal PSM were 8%, 4%, 7%, and 14%, respectively. In univariate analysis, overall PSM related to tPSA, f/tPSA, percentage of positive needles, and Gleason score. Multifocal PSM correlated with smoking history, drinking history, tPSA, f/tPSA, percentage of positive needles, and Gleason score. In multivariate analysis, percentage of positive needles reminded the only independent predictor for overall (OR = 10.5, 95% CI: 2.58–44.4) and basal PSM (OR = 24.0, 95% CI: 3.22–179.4). The f/tPSA (OR = 2.59, 95% CI: 2.18–5.71) and percentage of positive needles (OR = 31.0, 95% CI: 3.17–303) were independent risk factors for multifocal PSM.

Conclusion

The multifocal sites were the most common location of positive surgical margin, followed by apical and basal sites among Chinese patients undergoing RARP. The percentage of positive needles was an independent predictor for overall, basal, and multifocal PSM.

A non-inferiority comparative analysis of micro-ultrasonography and MRI-targeted biopsy in men at risk of prostate cancer

OBJECTIVE

To compare the efficacy of multiparametric magnetic resonance imaging (mpMRI)-directed and micro-ultrasonography (micro-US)-directed biopsy for detecting clinically significant (Grade Group >1) prostate cancer (csPCa).

MATERIALS AND METHODS

A total of 203 patients were prospectively enrolled at three institutions across Germany and Austria in the period from January 2019 to December 2019. During each biopsy, the urologist was blinded to the mpMRI report until after the micro-US targets had been assessed. After unblinding, targets were then sampled using software-assisted fusion, followed by systematic samples. The primary outcome measure was non-inferiority of micro-US to detect csPCa, with a detection ratio of at least 80% that of mpMRI.

RESULTS

A total of 79 csPCa cases were detected overall (39%). Micro-US-targeted biopsy detected 58/79 cases (73%), while mpMRI-targeted biopsy detected 60/79 (76%) and non-targeted (completion sampling) samples detected 45/79 cases (57%). mpMRI-targeted samples alone detected 7/79 (9%) csPCa cases which were missed by micro-US-targeted and non-targeted samples. Three of these seven were anterior lesions with 2/7 in the transition zone. Micro-US-targeted samples alone detected 5/79 (6%) and completion sampling alone detected 4/79 cases (5%). Micro-US was non-inferior to mpMRI and detected 97% of the csPCa cases detected by mpMRI-targeted biopsy (95% CI 80-116%; P = 0.023).

CONCLUSIONS

This is the first multicentre prospective study comparing micro-US-targeted biopsy with mpMRI-targeted biopsy. The study provides further evidence that micro-US can reliably detect cancer lesions and suggests that micro-US biopsy might be as effective as mpMRI for detection of csPCA. This result has significant implications for increasing accessibility, reducing costs and expediting diagnosis.

Comparison of PI-RADS Versions 2.0 and 2.1 for MRI-based Calculation of the Prostate Volume

RATIONALE AND OBJECTIVES

Prostate gland volume (PGV) should be routinely included in MRI reports of the prostate. The recently updated Prostate Imaging Reporting and Data System (PI-RADS) version 2.1 includes a change in the recommended measurement method for PGV compared to version 2.0. The purpose of this study was to evaluate the agreement of MRI-based PGV calculations with the volumetric manual slice-by-slice prostate segmentation as a reference standard using the linear measurements per PI-RADS versions 2.0 and 2.1. Furthermore, to assess inter-reader agreement for the different measurement approaches, determine the influence of an enlarged transition zone on measurement accuracy and to assess the value of the bullet formula for PGV calculation.

MATERIALS AND METHODS

Ninety-five consecutive treatment-naive patients undergoing prostate MRI were retrospectively analyzed. Prostates were manually contoured and segmented on axial T2-weighted images. Four different radiologists independently measured the prostate in three dimensions according to PI-RADS v2.0 and v2.1, respectively. MRI-based PGV was calculated using the ellipsoid and bullet formulas. Calculated volumes were compared to the reference manual segmentations using Wilcoxon signed-rank test. Inter-reader agreement was calculated using intraclass correlation coefficient (ICC).

RESULTS

Inter-reader agreement was excellent for the ellipsoid and bullet formulas using PI-RADS v2.0 (ICC 0.985 and 0.987) and v2.1 (ICC 0.990 and 0.994), respectively. The median difference from the reference standard using the ellipsoid formula derived PGV was 0.4 mL (interquartile range, -3.9 to 5.1 mL) for PI-RADS v2.0 (p = 0.393) and 2.6 mL (interquartile range, -1.6 to 7.3 mL) for v2.1 (p < 0.001) with a median difference of 2.2 mL. The bullet formula overestimated PGV by a median of 13.3 mL using PI-RADS v2.0 (p < 0.001) and 16.0 mL using v2.1 (p < 0.001). In the presence of an enlarged transition zone the PGV tended to be higher than the reference standard for PI-RADS v2.0 (median difference of 4.7 mL; p = 0.018) and for v2.1 (median difference of 5.7 mL, p < 0.001) using the ellipsoid formula.

CONCLUSION

Inter-reader agreement was excellent for the calculated PGV for both methods. PI-RADS v2.0 measurements with the ellipsoid formula yielded the most accurate volume estimates. The differences between PI-RADS v2.0 and v2.1 were statistically significant although small in absolute numbers but may be of relevance in specific clinical scenarios like prostate-specific antigen density calculation. These findings validate the use of the ellipsoid formula and highlight that the bullet formula should not be used for prostate volume estimation due to systematic overestimation.

Developing Strategy to Predict the Results of Prostate Multiparametric Magnetic Resonance Imaging and Reduce Unnecessary Multiparametric Magnetic Resonance Imaging Scan

Purpose

The clinical utility of multiparametric magnetic resonance imaging (mpMRI) for the detection and localization of prostate cancer (PCa) has been evaluated and validated. However, the implementation of mpMRI into the clinical practice remains some burden of cost and availability for patients and society. We aimed to predict the results of prostate mpMRI using the clinical parameters and multivariable model to reduce unnecessary mpMRI scans.

Methods

We retrospectively identified 784 men who underwent mpMRI scans and subsequent prostate biopsy between 2016 and 2020 according to the inclusion criterion. The cohort was split into a training cohort of 548 (70%) patients and a validation cohort of 236 (30%) patients. Clinical parameters including age, prostate-specific antigen (PSA) derivates, and prostate volume (PV) were assessed as the predictors of mpMRI results. The mpMRI results were divided into groups according to the reports: “negative”, “equivocal”, and “suspicious” for the presence of PCa.

Results

Univariate analysis showed that the total PSA (tPSA), free PSA (fPSA), PV, and PSA density (PSAD) were significant predictors for suspicious mpMRI (P < 0.05). The PSAD (AUC = 0.77) and tPSA (AUC = 0.74) outperformed fPSA (AUC = 0.68) and PV (AUC = 0.62) in the prediction of the mpMRI results. The multivariate model (AUC = 0.80) had a similar diagnostic accuracy with PSAD (P = 0.108), while higher than tPSA (P = 0.024) in predicting the mpMRI results. The multivariate model illustrated a better calibration and substantial improvement in the decision curve analysis (DCA) at a threshold above 20%. Using the PSAD with a 0.13 ng/ml² cut-off could spare the number of mpMRI scans by 20%, keeping a 90% sensitivity in the prediction of suspicious MRI-PCa and missing three (3/73, 4%) clinically significant PCa cases. At the same sensitivity level, the multivariate model with a 32% cut-off could spare the number of mpMRI scans by 27%, missing only one (1/73, 1%) clinically significant PCa case.

Conclusion

Our multivariate model could reduce the number of unnecessary mpMRI scans without comprising the diagnostic ability of clinically significant PCa. Further prospective validation is required.

Prostate Volume Estimation on MRI: Accuracy and Effects of Ellipsoid and Bullet-Shaped Measurements on PSA Density

RATIONALE AND OBJECTIVES

PSA density (PSAd), an important decision-making parameter for patients with suspected prostate cancer (PCa), is dependent on magnetic resonance imaging prostate volume (PV) estimation. We aimed to compare the accuracy of the ellipsoid and bullet-shaped formulas with manual whole-gland segmentation as reference standard and to evaluate the corresponding PSAd diagnostic accuracy in predicting clinically significant PCa.

MATERIALS AND METHODS

We retrospectively analysed 195 patients with suspected PCa who underwent magnetic resonance imaging and prostate biopsy. Patients with PCa were categorized according to ISUP score. PV and corresponding PSAd were calculated with manual segmentation (mPV and mPSAd) as well as with ellipsoid (ePV and ePSAd) and bullet-shaped (bPV and bPSAd) formulas. Inter and intra-reader reproducibility were assessed with Lin's concordance correlation coefficient and the intraclass correlation coefficient (ICC). A 2-way analysis of variance with post-hoc Bonferroni test was used for assessing PV differences. Predictive values of PSAd calculated with different methods for detecting clinically significant PCa were evaluated by receiver operating characteristic curve analysis and Youden's index.

RESULTS

Both intra (ρ = 0.99, ICC = 0.99) and inter-reader (ρ = 0.98, ICC = 0.98) reproducibility were excellent. No significant difference was found between ePV and reference standard (p = 1.00). bPV was significantly different from both (p = 0.00). PSAd (mPSAd/ePSAd cut-off ≥ 0.15, bPSAd cut-off ≥ 0.12) had sensitivity = 69-70%, specificity = 72-75%, areas under the curve = 0.757-0.760 (p = 0.70-0.88).

CONCLUSIONS

Our work shows that when using bullet-shaped formula, a different PSAd cut-off must be considered to avoid PCa under-diagnosis and inaccurate risk-stratification.

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.

A prospective study of the effect of testosterone escape on preradiotherapy prostate-specific antigen kinetics in prostate cancer patients undergoing neoadjuvant androgen deprivation therapy

Introduction

Prostate-specific antigen (PSA) kinetic patterns during neoadjuvant androgen deprivation therapy have been shown to predict unfavorable long-term outcomes.

Objective

To investigate the effect of testosterone escape (TE) on these kinetic patterns, as this had not been previously reported.

Methods

There were 50 consecutive prostate cancer patients who received 6 months of triptorelin prior to definitive radiotherapy (RT). Testosterone and PSA levels were measured at baseline and every 6 weeks. Clinical factors were tested for their ability to predict for TE and unfavorable PSA kinetic patterns. The effects of TE, at both 1.7 and 0.7 nmol/L levels, were analyzed.

Results

TE occurred in at least one reading for 14% and 34% of the patients at the 1.7 and 0.7 nmol/L levels, respectively. No baseline factors predicted TE. The median PSA halving time was 25 days and the median pre-RT PSA level was 0.55 ng/mL. The only factor significantly associated with a higher pre-RT PSA level was a higher baseline PSA level. The only factor that significantly predicted a longer PSA halving time was TE at the 1.7 nmol/L level.

Conclusions

TE and higher baseline PSA levels may adversely affect PSA kinetics and other outcomes for patients undergoing neoadjuvant hormone therapy prior to radiotherapy. Studies investigating the tailoring of neoadjuvant therapy by extending the duration in those patients with a higher baseline PSA level or by the addition of anti-androgens in those demonstrating TE, should be considered.

Accuracy of Clarius, Handheld Wireless Point-of-Care Ultrasound, in Evaluating Prostate Morphology and Volume Compared to Radical Prostatectomy Specimen Weight: Is There a Difference between Transabdominal vs Transrectal Approach?

Background: Prostate size estimation is a valuable clinical measure widely utilized in urology. This study evaluated the accuracy of preoperative transabdominal ultrasound (TAUS) compared to radical prostatectomy specimens and transrectal ultrasound (TRUS) in estimating prostate volume and identifying presence of median lobe, across different size groups, using the standard ellipsoid formula. The effect of median lobe on accuracy was also assessed. Materials and Methods: Ninety-eight men undergoing robot-assisted radical prostatectomy were enrolled in this study. Preoperative evaluation of prostate volume was done using measurements obtained from TAUS using the Clarius C3 handheld wireless point-of-care ultrasound (POCUS) and from TRUS Clarius EC7. Participants were grouped based on prostate size (<30, 30-60, and >60 g). Mean absolute percentage of error was used to evaluate accuracy. Mean percentage of error determined if there was an overestimation or underestimation. Correlation between each TAUS size group, true prostate weight and TRUS was assessed. Results: Irrespective of body mass index, TAUS accurately identified median lobe in all men. No statistically significant difference was found between specimen weight and TAUS prostate size for the >60 g group. Among this same group, a strong correlation was noted between specimen weight and TAUS prostate size (r = 0.911, p < 0.001). There was also a strong correlation between TAUS and TRUS measurements for this group (r = 0.950, p < 0.001). Presence of median lobe did not have an impact on measurement accuracy. Conclusions: Bedside handheld wireless POCUS provides rapid, inexpensive, noninvasive, and clinically accurate TAUS prostate assessments for larger prostates. Such features as identifying median lobes and measuring prostate volumes are valuable tools, whereas patient counseling on lower urinary tract symptoms, elevated prostate-specific antigen, and benign prostate hyperplasia are surgical options.

Diagnosis of Prostate Cancer in Patients with Prostate-Specific Antigen (PSA) in the Gray Area: Construction of 2 Predictive Models

Background

Two diagnostic models of prostate cancer (PCa) and clinically significant prostate cancer (CS-PCa) were established using clinical data of among patients whose prostate-specific antigen (PSA) levels are in the gray area (4.0–10.0 ng/ml).

Material/Methods

Data from 181 patients whose PSA levels were in the gray area were retrospectively analyzed, and the following data were collected: age, digital rectal examination, total PSA, PSA density (PSAD), free/total PSA (f/t PSA), transrectal ultrasound, multiparametric magnetic resonance imaging (mpMRI), and pathological reports. Patients were diagnosed with benign prostatic hyperplasia (BPH) and PCa by pathology reports, and PCa patients were separated into non-clinically significant PCa (NCS-PCa) and CS-PCa by Gleason score. Afterward, predictor models constructed by above parameters were researched to diagnose PCa and CS-PCa, respectively.

Results

According to the analysis of included clinical data, there were 109 patients with BPH, 44 patients with NCS-PCa, and 28 patients with CS-PCa. Regression analysis showed PCa was correlated with f/t PSA, PSAD, and mpMRI (P<0.01), and CS-PCa was correlated with PSAD and mpMRI (P<0.01). The area under the receiver operating characteristic curves of 2 models for PCa (sensitivity=73.64%, specificity=64.23%) and for CS-PCa (sensitivity=71.41%, specificity=81.82%) were 0.79 and 0.87, respectively.

Conclusions

The prediction models had satisfactory diagnostic value for PCa and CS-PCa among patients with PSA in the gray area, and use of these models may help reduce overdiagnosis.

Multivariable Models Incorporating Multiparametric Magnetic Resonance Imaging Efficiently Predict Results of Prostate Biopsy and Reduce Unnecessary Biopsy

Purpose

We sought to develop diagnostic models incorporating mpMRI examination to identify PCa (Gleason score≥3+3) and CSPCa (Gleason score≥3+4) to reduce overdiagnosis and overtreatment.

Methods

We retrospectively identified 784 patients according to inclusion criteria between 2016 and 2020. The cohort was split into a training cohort of 548 (70%) patients and a validation cohort of 236 (30%) patients. Age, PSA derivatives, prostate volume, and mpMRI parameters were assessed as predictors for PCa and CSPCa. The multivariable models based on clinical parameters were evaluated using area under the curve (AUC), calibration plots, and decision curve analysis (DCA).

Results

Univariate analysis showed that age, tPSA, PSAD, prostate volume, MRI-PCa, MRI-seminal vesicle invasion, and MRI-lymph node invasion were significant predictors for both PCa and CSPCa (each p≤0.001). PSAD has the highest diagnostic accuracy in predicting PCa (AUC=0.79) and CSPCa (AUC=0.79). The multivariable models for PCa (AUC=0.92, 95% CI: 0.88–0.96) and CSPCa (AUC=0.95, 95% CI: 0.92–0.97) were significantly higher than the combination of derivatives for PSA (p=0.041 and 0.009 for PCa and CSPCa, respectively) or mpMRI (each p<0.001) in diagnostic accuracy. And the multivariable models for PCa and CSPCa illustrated better calibration and substantial improvement in DCA at threshold above 10%, compared with PSA or mpMRI derivatives. The PCa model with a 30% cutoff or CSPCa model with a 20% cutoff could spare the number of biopsies by 53%, and avoid the number of benign biopsies over 80%, while keeping a 95% sensitivity for detecting CSPCa.

Conclusion

Our multivariable models could reduce unnecessary biopsy without comprising the ability to diagnose CSPCa. Further prospective validation is required.

PET and MRI guided adaptive radiotherapy: Rational, feasibility and benefit

Adaptive radiotherapy (ART) corresponds to various replanning strategies aiming to correct for anatomical variations occurring during the course of radiotherapy. The goal of the article was to report the rational, feasibility and benefit of using PET and/or MRI to guide this ART strategy in various tumor localizations. The anatomical modifications defined by scanner taking into account tumour mobility and volume variation are not always sufficient to optimise treatment. The contribution of functional imaging by PET or the precision of soft tissue by MRI makes it possible to consider optimized ART. Today, the most important data for both PET and MRI are for lung, head and neck, cervical and prostate cancers. PET and MRI guided ART appears feasible and safe, however in a very limited clinical experience. Phase I/II studies should be therefore performed, before proposing cost-effectiveness comparisons in randomized trials and before using the approach in routine practice.

How accurately can multiparametric magnetic resonance imaging measure the tumour volume of a prostate cancer? Results of a systematic review

The tumour volume of a cancer within the prostate gland is commonly measured with multiparametric MRI. The measurement has a role in many clinical scenarios including focal therapy, but the accuracy of it has never been systematically reviewed. We included articles if they compared tumour volume measurements obtained by mpMRI with a reference volume measurement obtained after radical prostatectomy. Correlation and concordance statistics were summarised. A simple accuracy score was derived by dividing the given mean or median mpMRI volume by the histopathological reference volume. Factors affecting the accuracy were noted. Scores for potential bias and quality were calculated for each article. A total of 18 articles describing 1438 patients were identified. Nine articles gave Pearson's correlation scores, with a median value of 0.75 but the range was wide (0.42-0.97). A total of 11 articles reported mean values for volume while 9 reported median values. For all 18 articles, the mean or median values for MRI volumes were lower than the corresponding reference values suggesting consistent underestimation. For articles reporting mean and median values for volume, the median accuracy scores were 0.83 and 0.80, respectively. The accuracy was higher for tumours of greater volume, higher grade and when an endorectal coil was used. Accuracy did not seem to improve over time, with a 3 Tesla magnet or by applying a shrinkage factor to the reference measurement. Most studies showed evidence of at least moderate bias, and their quality was highly variable, but neither of these appeared to affect accuracy.

Using clinical parameters to predict prostate cancer and reduce the unnecessary biopsy among patients with PSA in the gray zone

The gold standard for prostate cancer (PCa) diagnosis is prostate biopsy. However, it remines controversial as an invasive mean for patients with PSA levels in the gray zone (4–10 ng/mL). This study aimed to develop strategy to reduce the unnecessary prostate biopsy. We retrospectively identified 235 patients with serum total PSA testing in the gray zone before prostate biopsy between 2014 and 2018. Age, PSA derivates, prostate volume and multiparametric magnetic imaging (mpMRI) examination were assessed as predictors for PCa and clinically significant PCa with Gleason score ≥ 7 (CSPCa). Univariate analysis showed that prostate volume, PSAD, and mpMRI examination were significant predictors of PCa and CSPCa (P < 0.05). The differences of diagnostic accuracy between mpMRI examination (AUC = 0.69) and other clinical parameters in diagnostic accuracy for PCa were not statistically significant. However, mpMRI examination (AUC = 0.79) outperformed prostate volume and PSAD in diagnosis of CSPCa. The multivariate models (AUC = 0.79 and 0.84 for PCa and CSPCa) performed significantly better than mpMRI examination for detection of PCa (P = 0.003) and CSPCa (P = 0.036) among patients with PSA level in the gray zone. At the same level of sensitivity as the mpMRI examination to diagnose PCa, applying the multivariate models could reduce the number of biopsies by 5% compared with mpMRI examination. Overall, our results supported the view that the multivariate model could reduce unnecessary biopsies without compromising the ability to diagnose PCa and CSPCa. Further prospective validation is required.

Is prospective MRI mapping of the changes in the volume of the prostate gland in prostate cancer patients undergoing 6 months of neo-adjuvant androgen deprivation therapy a step towards a trial to determine those who may benefit from treatment intensification or extended duration?

INTRODUCTION

Neo-adjuvant androgen deprivation therapy prior to radiotherapy (RT) causes shrinkage of the prostate gland, but the changes in volume have never been mapped over time in detail, nor have the associations between volume reduction and testosterone escape or prostate-specific antigen (PSA) kinetics been determined.

METHODS

Fifty consecutive patients with prostate cancer were treated with 6 months of triptorelin prior to definitive RT. The volume of the prostate gland was measured at the outset and every 6-7 weeks thereafter using MRI scans. The volumes were calculated using a planimetric method, and inter-rater reliability was checked. Factors associated with a large initial volume and greater reductions in it were assessed.

RESULTS

The median volume at the outset was 45 cc, and the median reductions every 6 weeks thereafter were 23, 18, 9 and 5%. The inter-rater agreement was high (r > 0.9, P < 0.001). There were no baseline clinical factors associated with a high initial prostate volume, but the initial volume was associated with greater volume reduction. Testosterone escape had no effect on the reduction, and changes in volume were not reflected in PSA response kinetics.

CONCLUSIONS

Reductions in volume continue throughout a 6-month course of neo-adjuvant therapy but are greatest during the first 6 weeks. Although individualisation of the duration or intensity of the hormone treatment warrants further investigation, the role of prostate gland volume reduction remains uncertain. More detailed studies of tumour volume might be possible if the imaging required was acceptable and accessible to patients.

Prostate volume measurement by multiparametric magnetic resonance and transrectal ultrasound: comparison with surgical specimen weight

Objective

To assess accuracy of multiparametric magnetic resonance of the prostate to estimate gland volume, comparing the results with transrectal ultrasound and surgical specimen.

Methods

A retrospective study of 85 patients who underwent multiparametric magnetic resonance and transrectal ultrasound (for fusion image-guided biopsy) before radical prostatectomy. Prostate measurements were obtained from magnetic resonance axial and sagittal T2-weighted images and ultrasound; the prostate volume was determined using the ellipsoid formula. The results were compared with the surgical specimen weight. Maximum interval between multiparametric magnetic resonance imaging, transrectal ultrasound, and prostatectomy was 6 months.

Results

The prostate volume measured by multiparametric magnetic resonance imaging was 18-157cm³ (mean of 49.9cm³) and by transrectal ultrasound, 22-165cm³ (mean of 54.9cm³); the surgical specimen weight was 20-154g (mean of 48.6g), with no statistical differences. Based on the values obtained from imaging examinations, the prostate volume obtained was very close to the real prostatic weight, and the measures by multiparametric magnetic resonance were slightly more precise.

Conclusion

Prostate volume measured by multiparametric magnetic resonance imaging and transrectal ultrasound showed similar values, and excellent agreement with real prostate weight of the surgical specimens. Prostate volume measured by magnetic resonance has been increasingly used in the clinical practice, and its value enables appropriate therapeutic planning and control of patients.

Inter-imaging accuracy of computed tomography, magnetic resonance imaging, and transrectal ultrasound in measuring prostate volume compared to the anatomic prostatic weight

OBJECTIVE

To evaluate the accuracy of transrectal ultrasound (TRUS), computed tomography (CT), and magnetic resonance imaging (MRI) compared to the reference standard of the post-surgical anatomic prostatic weight (APW).

MATERIAL AND METHODS

A total of 349 patients from two institutions were included. The CT and MRI dimensions, and TRUS-reported prostate volumes (PV) were obtained. The prolate ellipsoid formula was used to calculate PV. Cross-sectional measurements were evaluated and compared to the reported post-surgical pathology measurements and calculated pathology volume (path PV). A basic statistical analysis was performed using the Pearson correlation, Bland-Altman analysis, and Passing-Bablok regression.

RESULTS

A total of 198 patients were included in the MRI group, 118 in the CT group, 295 in the TRUS group, and 51 in the all-inclusive common cohort. The MRI PV demonstrated a good to excellent correlation with the APW (r=0.79). The CT PV demonstrated a good correlation with APW (r=0.78). The TRUS PV showed a correlation with APW (r=0.67). The correlations identified in each individual group held true in the common cohort as well. The path PV showed an excellent correlation with APW (r=0.87), followed by MRI PV (r=0.81), then CT PV (r=0.73), and lastly TRUS PV (r=0.71).

CONCLUSION

MRI and CT are equally effective in assessing the PV, and they can be readily utilized to guide the benign prostatic hyperplasia (BPH) management without repeating in-office TRUS. This is not only cost-effective, but also eliminates patient anxiety and discomfort.

Cartilage oligomeric matrix protein in patients with osteoarthritis is independently associated with metastatic disease in prostate cancer

Metastatic prostate cancer has a 5-year survival rate of 30%. Identifying predictors of metastasis outcome could potentially reduce patient mortality. The objective of this study was to determine whether osteoarthritis had an impact on outcomes of prostate cancer including death, local recurrence and/or metastasis and to determine whether cartilage oligomeric matrix protein was involved. We performed a retrospective case-control study of patients with prostate cancer with and without the diagnosis of osteoarthritis and completed immunohistochemistry (IHC) analysis of prostate (n=20) and lymph node (n=7) surgical specimens. We evaluated death, local recurrence and metastatic disease by various IHC biomarkers including prostate specific membrane antigen (PSMA), cartilage oligomeric matrix protein (COMP), CD31, and Ki-67. Our model identified osteoarthritis as an independent risk factor for metastatic disease (OR 5.24, 95% CI 1.49 - 18.41). Most notably, when joint arthroplasty was included in the model, osteoarthritis was no longer an independent risk factor for this outcome (p=0.071). IHC demonstrated that those with osteoarthritis, had greater expression of COMP in the prostate samples (mean 23.9% vs 5.84%, p<0.05) but not of Ki-67, CD31, or PSMA. This study identified and quantified increased metastatic disease in patients with osteoarthritis. Also, patients with osteoarthritis expressed increased COMP levels in the prostate and most likely in distant lymphatic nodes. Moreover, our findings suggest that joint arthroplasty may affect the ability of osteoarthritis to promote metastasis, which could impact treatment protocols and survival outcomes of the most common cause of cancer-related death (metastasis) in the United States.

A systematic review of the accuracy of the digital rectal examination as a method of measuring prostate gland volume

Objective:

There are many important clinical scenarios in which estimates of the volume of the prostate gland can have an influence on clinical decisions. The digital rectal examination is the simplest and most readily available method for measuring it. It is commonly performed numerous times every day by practising urologists and radiation oncologists. The prostate gland volume is the most studied parameter arising from it. Although reported in many heterogeneous studies, the accuracy of the digital rectal examination in measuring the volume has never been reviewed. Our aim was to conduct the world’s first systematic review.

Methods:

Articles from the literature were included if they compared the digital rectal examination with more accurate measures including fluid displacement after radical prostatectomy and transrectal ultrasound measurements.

Results:

Nineteen articles describing 7891 patients were reviewed and summarised. Wide variations were noted but most studies provided correlation coefficients that lay between 0.3 and 0.7. For those studies that did not involve special training in volume estimation or were not conducted by a urologist with a special interest in the correlation, the coefficients were below 0.6. For eight studies that analysed the estimated volume as a categorical variable, concordance was described using a variety of statistical tests but was generally high.

Conclusions:

The reported correlations were weak to moderate strength indicating that the digital rectal examination may not be accurate enough when quantitative measurements are required. However, enlargement of the prostate was detectable with high levels of concordance, indicating that the digital rectal examination is effective for that purpose.

Level of evidence:

Not applicable for this multicentre audit.