Magnetic Resonance Imaging Detection of Glucose-Stimulated Zinc Secretion in the Enlarged Dog Prostate as a Potential Method for Differentiating Prostate Cancer From Benign Prostatic Hyperplasia

OBJECTIVES

In the United States, prostate cancer (PCa) is the most common cancer in men. Multi-parametric magnetic resonance imaging (MRI) is increasingly being relied upon for the diagnosis and characterization of PCa, but differentiating malignancy from benign prostatic hyperplasia (BPH) in the transition zone using MRI can be challenging. The characteristically high levels of zinc in human prostate tissue and a close relationship between malignant proliferation and zinc homeostatic dysregulation create opportunities to visualize PCa with novel contrast media. In mouse models, glucose-stimulated zinc secretion (GSZS) can be preferentially observed in healthy prostate tissue compared with malignant tissue; in vivo, these differences can be captured with MRI by using Gdl1, a gadolinium-based zinc-responsive contrast agent. In this study, we examined whether this technology can be applied in a large animal model by imaging older dogs with clinically diagnosed BPH.

MATERIALS AND METHODS

Four intact male dogs 6 years or older with enlarged prostates were imaged (T1-weighted turbo spin-echo, TE/TR, 12/400 milliseconds and T2-weighted, TE/TR, 112/5000 milliseconds) using a 3 T scanner before and at multiple time points after intravenous injection of 0.05 mmol/kg GdL1 plus either (a) 2 mL/kg of 50% dextrose in 1 session or (b) 2 mL/kg normal saline in another session. The two sessions were one week apart, and their order was randomly determined for each dog. During postprocessing, regions of interest were generated in prostate tissue and in paraspinal muscles to evaluate the contrast-to-noise ratio (CNR). The ratio of CNR at any postinjection time point compared with baseline CNR was defined as r-CNR. After the second imaging session, the dogs were euthanized, and their prostates were harvested for histopathological examination. Baseline and postintervention plasma and urine samples were analyzed for total zinc by inductively coupled plasma mass spectrometry.

RESULTS

The mean ± SD r-CNR values at 13 minutes postinjection in the dextrose versus saline imaging sessions were 134% ± 10% and 127% ± 7%, respectively (P < 0.01). The histopathologic evaluation of prostate tissues confirmed BPH in all dogs. Interestingly, prostatic intraepithelial neoplasia was detected in 1 animal, and a suspicious mass was found in the same region on T2-weighted scans. The r-CNR of the mass was calculated as 113% ± 4% and 111% ± 6% in the dextrose and saline groups, respectively, with no significant differences between the 2 interventions (P = 0.54), whereas there was a statistically significant difference between the r-CNR of the whole prostate in the dextrose (130% ±11%) and saline (125% ± 9%) interventions (P = 0.03). Inductively coupled plasma mass spectrometry analyses showed a significantly higher urinary zinc in the dextrose versus saline groups, but no differences were found in plasma zinc levels.

CONCLUSIONS

T1-weighted MRI of the enlarged canine prostate showed higher r-CNR after injection of GdL1 plus dextrose compared with GdL1 plus saline, consistent with GSZS from BPH tissues. One small region of neoplastic tissue was identified in a single dog on the basis of less GSZS from that region by MRI. These findings suggest a new method for the detection of PCa by MRI that could facilitate the differentiation of BPH from PCa in the transition zone.

Correlation of prostatic morphological parameters and clinical progression in aging Chinese men with benign prostatic hyperplasia: Results from a cross-sectional study

OBJECTIVES

Our study aimed to investigate the correlation of prostatic morphological parameters and benign prostatic hyperplasia (BPH) clinical progression in aging Chinese men.

METHODS

In this retrospective study, a total of 1038 patients were reviewed. Prostatic morphology was measured by transrectal ultrasound (TRUS). Detailed medical history of all candidates was recorded and analyzed after being classified by specific prostatic measurements. Univariate and multivariate logistic regression analyses were used to estimate the correlation between variables.

RESULTS

The cumulative incidence of BPH clinical progression was 63.68% (661/1038) in the study population. Prostate volume (PV), transitional zone volume (TZV), transitional zone index (TZI), and intravesical prostatic protrusion (IPP) were all positively associated with BPH progression (all p < .001). Patients with a PV > 60 ml, TZV > 15 ml, TZI > 0.5, or IPP > 5 mm had a significantly higher possibility of overall BPH clinical progression (adjusted odds ratio (OR): 2.485, 1.678, 1.886, and 1.924, respectively; 95% confidence interval (CI): 1.559-3.960, 1.131-2.489, 1.379-2.579, and 1.357-2.728, correspondingly).

CONCLUSION

Prostatic morphological parameters are significantly associated with BPH clinical progression. Patients with larger prostatic morphological parameters are more easily prone to clinical progress. As a result, reasonable managements should be timely considered for those patients before clinical progression occurs.

IVIM-DKI for differentiation between prostate cancer and benign prostatic hyperplasia: comparison of 1.5 T vs. 3 T MRI

OBJECTIVE

To implement an advanced spatial penalty-based reconstruction to constrain the intravoxel incoherent motion (IVIM)-diffusion kurtosis imaging (DKI) model and investigate whether it provides a suitable alternative at 1.5 T to the traditional IVIM-DKI model at 3 T for clinical characterization of prostate cancer (PCa) and benign prostatic hyperplasia (BPH).

MATERIALS AND METHODS

Thirty-two patients with biopsy-proven PCa were recruited for MRI examination (n = 16 scanned at 1.5 T, n = 16 scanned at 3 T). Diffusion-weighted imaging (DWI) with 13 b values (b = 0 to 2000 s/mm² up to 3 averages, 1.5 T: TR = 5.774 s, TE = 81 ms and 3 T: TR = 4.899 s, TE = 100 ms), T2-weighted, and T1-weighted imaging were used on the 1.5 T and 3 T MRI scanner, respectively. The IVIM-DKI signal was modeled using the traditional IVIM-DKI model and a novel model in which the total variation (TV) penalty function was combined with the traditional model to optimize non-physiological variations. Paired and unpaired t-tests were used to compare intra-scanner and scanner group differences in IVIM-DKI parameters obtained using the novel and the traditional models. Analysis of variance with post hoc test and receiver operating characteristic (ROC) curve analysis were used to assess the ability of parameters obtained using the novel model (at 1.5 T) and the traditional model (at 3 T) to characterize prostate lesions.

RESULTS

IVIM-DKI modeled using novel model with TV spatial penalty function at 1.5 T, produced parameter maps with 50-78% lower coefficient of variation (CV) than traditional model at 3 T. Novel model estimated higher D with lower D*, f and k values at both field strengths compared to traditional model. For scanner differences, the novel model at 1.5 T estimated lower D* and f values as compared to traditional model at 3 T. At 1.5 T, D and f values were significantly lower with k values significantly higher in tumor than BPH and healthy tissue. D (AUC: 0.98), f (AUC: 0.82), and k (AUC: 0.91) parameters estimated using novel model showed high diagnostic performance in cancer lesion detection at 1.5 T.

DISCUSSION

In comparison with the IVIM-DKI model at 3 T, IVIM-DKI signal modeled with the TV penalty function at 1.5 T showed lower estimation errors. The proposed novel model can be utilized for improved detection of prostate lesions.

Using prostate contrast retention (PCR) as the procedural endpoint in prostatic artery embolization for benign prostatic hyperplasia

OBJECTIVES

The failure rate following prostate artery embolization (PAE) is around 20%, which may in part result from inadequate embolization. Prostate contrast retention (PCR) adequacy on immediate post-embolization cone-beam CT may provide better assessment of embolization completeness than arterial contrast stasis seen on fluoroscopy alone. The aim of this study was to evaluate outcomes of PAE using PCR adequacy as the procedural endpoint.

METHODS

A retrospective cohort study of all PAE cases using this technique at a single large volume center was conducted. Following initial embolization of the main prostatic arteries, if PCR was inadequate, additional embolization was performed. Technical success (adequate PCR) was defined as > 75% global prostate gland contrast staining. Clinical success was determined in accordance to CIRSE standards of practice.

RESULTS

One hundred sixty-five patients (mean age 68 ± 8.4 years) underwent PAE from June 2017 to March 2019. Technical and clinical success rates were 98.8% and 96.4% respectively. Clinical success rate was significantly higher in patients with adequate PCR. International Prostate Symptom Scores (IPSS) and Quality of Life (QoL) scores significantly improved at 1-, 3-, 6-, and 12-month follow-up when compared to baseline. Prostate volume (PV) and post-voiding residual bladder volume were significantly reduced at 3, 6, and 12 months in comparison to baseline. Mild (Clavien-Dindo grade I/II) and moderate (grade III) complication rates were 12.1% and 3.6% respectively.

CONCLUSIONS

By using PCR adequacy as a guide to determine the procedure endpoint for PAE, it may be possible to achieve more complete embolization and thus higher clinical success rates.

KEY POINTS

• By using PCR adequacy as a guide to determine the procedure endpoint for PAE, it may be possible to achieve more complete embolization and thus higher clinical success rates.

Exploring the diagnostic potential of adding T2 dependence in diffusion-weighted MR imaging of the prostate

Background

Magnetic resonance imaging (MRI) is essential in the detection and staging of prostate cancer. However, improved tools to distinguish between low-risk and high-risk cancer are needed in order to select the appropriate treatment.

Purpose

To investigate the diagnostic potential of signal fractions estimated from a two-component model using combined T2- and diffusion-weighted imaging (T2-DWI).

Material and methods

62 patients with prostate cancer and 14 patients with benign prostatic hyperplasia (BPH) underwent combined T2-DWI (TE = 55 and 73 ms, b-values = 50 and 700 s/mm²) following clinical suspicion of cancer, providing a set of 4 measurements per voxel. Cancer was confirmed in post-MRI biopsy, and regions of interest (ROIs) were delineated based on radiology reporting. Signal fractions of the slow component (SF_slow) of the proposed two-component model were calculated from a model fit with 2 free parameters, and compared to conventional bi- and mono-exponential apparent diffusion coefficient (ADC) models.

Results

All three models showed a significant difference (p<0.0001) between peripheral zone (PZ) tumor and normal tissue ROIs, but not between non-PZ tumor and BPH ROIs. The area under the receiver operating characteristics curve distinguishing tumor from prostate voxels was 0.956, 0.949 and 0.949 for the two-component, bi-exponential and mono-exponential models, respectively. The corresponding Spearman correlation coefficients between tumor values and Gleason Grade Group were fair (0.370, 0.499 and -0.490), but not significant.

Conclusion

Signal fraction estimates from a two-component model based on combined T2-DWI can differentiate between tumor and normal prostate tissue and show potential for prostate cancer diagnosis. The model performed similarly to conventional diffusion models.

Quantitative Characterization of the Prostatic Urethra Using MRI: Implications for Lower Urinary Tract Symptoms in Patients with Benign Prostatic Hyperplasia

INTRODUCTION

The aim of this study was to perform a quantitative assessment of the prostate anatomy with a focus on the relation of prostatic urethral anatomic variation to urinary symptoms.

METHODS

This retrospective study involved patients undergoing magnetic resonance imaging for prostate cancer who were also assessed for lower urinary tract symptoms. Volumetric segmentations were utilized to derive the in vivo prostatic urethral length and urethral trajectory in coronal and sagittal planes using a piece-wise cubic spline function to derive the angle of the urethra within the prostate. Association of anatomical factors with urinary symptoms was evaluated using ordinal univariable and multivariable logistic regression with IPSS score cutoffs of ≤7, 8-19, and >20 to define mild, moderate, and severe symptoms, respectively.

RESULTS

A total of 423 patients were included. On univariable analysis, whole prostate volume, transition zone volume, prostatic urethral length, urethral angle, and retrourethral volume were all significantly associated with worse urinary symptoms. On multivariable analysis prostatic urethral length was associated with urinary symptoms with a normalized odds ratio of 1.5 (95% confidence interval 1.0-2.2, p = 0.04). In a subset analysis of patients on alpha blockers, maximal urethral angle, transition zone volume as well as urethral length were all associated with worse urinary symptoms.

CONCLUSION

Multiple parameters were associated with worse urinary symptoms on univariable analysis, but only prostatic urethral length was associated with worse urinary symptoms on multivariable analysis. This study demonstrates the ability of quantitative assessment of prostatic urethral anatomy to predict lower urinary tract symptoms.

Effect of superselective prostatic artery embolization on benign prostatic hyperplasia

PURPOSE

To investigate the safety and effectiveness of superselective prostatic artery embolization (PAE) in patients with benign prostatic hyperplasia (BPH).

METHODS

Sixty-five patients diagnosed with BPH in Fujian Provincial Hospital between December 2014 and July 2019 were included. Patients with ineffective drug treatment after 6 months, who refused surgery, or who were unsuitable for surgery were included. We observed postoperative complications, followed up at 1, 3, and 6 months, compared clinical symptoms, and monitored changes in prostate-specific antigen (PSA) and prostatic volume (PV) before and after treatment.

RESULTS

Of the 65 patients, 58 (89.23%) successfully received PAE; 44 and 14 bilateral and unilateral embolization, respectively. Clinical efficacy was 94.83% (55/58) after the 6-month follow-up. Postoperative PV, International Prostate Symptom Score, quality of life, maximum flow rate, and post-void residual significantly improved after 6 months (P < 0.05). One month after PAE, the serum total PSA increased by 1.47 (10.84/7.37) times and dropped 3 months later to a level lower than that before surgery (P < 0.05). Six months after PAE, the degree of relief from obstructive symptoms was more apparent than that of irritative symptoms. No serious complications were observed after PAE.

CONCLUSION

PAE was safe and effective for the treatment of BPH. The efficacy of bilateral PAE was better than that of unilateral PAE.

A valuable MRI examination method for prostate cancer screening

To investigate the value of the 1.5T magnetic resonance imaging (MRI) apparent diffusion coefficient (ADC) and the prostate imaging reporting and data system (PI-RADS) score in prostate cancer (PCa) screening.Forty PCa patients diagnosed by pathology from December 2014 to September 2018 were recruited as the PCa group; 60 patients with benign prostatic hyperplasia (BPH) were recruited as the benign group. Patients from both groups underwent 1.5T MRI scanning. The prostate ADC values, exponential apparent diffusion coefficient (eADC) values, and PI-RADS scores of patients from the 2 groups were compared. The different methods for PCa diagnosis were compared.The ADC values of patients in the PCa group were significantly lower than those in the benign group, whereas the eADC values of patients were significantly higher than those in the benign group, with statistically significant differences (P < .05). The differences in the PI-RADS scores of patients from the 2 groups were statistically significant (P < .05). Receiver Operating Characteristic (ROC) curve results showed that the ADC value combined with the PI-RADS score was superior to the ADC value or the PI-RADS score alone in sensitivity, specificity, and Youden index for PCa diagnosis. By comparing the area under the curve (AUC) of each ROC curve from the different diagnostic methods, the combination of ADC value and PI-RADS score showed the largest area.The ADC value from 1.5T MRI combined with the PI-RADS score could be used as the standard for PCa screening, which would effectively improve screening for PCa and be valuable for clinical applications.

Diagnostic performance of transrectal ultrasound for prostate volume estimation in men with benign prostate hyperplasia

BACKGROUND AND AIM

Despite transrectal ultrasound (TRUS) being regarded as gold standard for prostate volume estimation, concerns have been raised in the literature concerning its accuracy especially in men with above-average prostate volumes. We aimed to evaluate the performance of TRUS for prostate volume estimation in a cohort of sub-Saharan African men since they are known to have relatively large mean prostate volumes.

METHODS

This was a prospective study of 77 sub-Saharan African men who had open simple prostatectomy for benign prostate hyperplasia (BPH). Pre-operative TRUS determined total prostate volume (TPV) and transition zone volume (TZV). Following surgical enucleation, the adenoma was weighed (EPW) and its volume (EPV) also determined by fluid displacement. TRUS was repeated six weeks post-operatively to calculate the TRUS-estimated specimen volume (TESV).

RESULTS

The mean EPV, EPW, TRUS-estimated TZV, TRUS-estimated TPV and TESV were 79.1 ± 62.9 ml, 79.1 ± 62.9 g, 53.3 ± 28.5 ml, 93.1 ± 48.9 ml and 69.9 ± 44.6 ml, respectively. Pearson's correlation showed a perfect relationship between EPW and EPV with no difference in their mean values (r = 1.000; P < .001). Pearson's correlation between TRUS-estimated TPV vs EPV, TRUS-estimated TZV vs EPV, and between TESV vs EPV were 0.932, 0.865 and 0.930, respectively (P = .0000). TRUS significantly under-estimated the TZV and TESV by 25.8 ml and 9.2 ml, respectively; unrelated to the severity of prostate enlargement.

CONCLUSION

TRUS underestimates prostate volume, independent of prostate size. We propose simple formulae that could be used to improve the prostate volume determination from TRUS, especially if magnetic resonance imaging is not readily available or contraindicated.

Prostatic Artery Embolization: Variant Origins and Collaterals

Prostate artery embolization (PAE) is a minimally invasive treatment for benign prostatic hyperplasia associated lower urinary tract symptoms. The prostatic arterial anatomy, origins and collaterals, are highly variable and can lead to technical pitfalls and suboptimal results during PAE. In this paper we aim to discuss the variant prostate artery origins and collateral circulation to provide a primer on relevant anatomy for interventional radiologists performing PAE.

Prostatic Artery Embolization in Refractory Hematuria of Prostatic Origin

Hematuria of prostatic origin has multiple etiologies including benign prostatic hyperplasia (BPH), iatrogenic urological trauma, prostate cancer, and radiation therapy. Hematuria secondary to benign prostatic hyperplasia can occur because of the increased vascularity of the primary gland, itself, or because of the vascular re-growth following a transurethral resection of the prostate. Prostatic hematuria usually resolves with conservative measures; however, refractory hematuria of prostatic origin may require hospitalization with treatment with blood transfusions, repeated indwelling urinary catheterization, and continuous bladder irrigation. Prostate artery embolization is an emerging minimally invasive procedural therapy for men with BPH that was originally utilized for the treatment of refractory hematuria of prostatic origin . This article aims to summarize the currently available evidence around prostate artery embolization for the treatment of refractory hematuria of prostatic origin.

Prostatic artery embolization in patients with benign prostatic hyperplasia: perfusion cone-beam CT to evaluate planning and treatment response

This proof of concept is to evaluate the utility of perfusion cone-beam computed tomography (CT) in patients undergoing prostatic artery (PA) embolization (PAE) for benign prostatic hyperplasia (BPH) with moderate or severe-grade lower urinary tract symptoms (LUTS). PAE is a novel minimally invasive therapy and is both safe and effective procedure with low risks and high technical successes, making this procedure as the best alternative to surgery. A lot of technical changes would compromise clinical outcomes after procedure, including a variable prostate vascular anatomy, thin PA, and extensive atherosclerotic disease. The purpose of our study is to exploit the advantages of Perfusion Cone Beam Computed Tomography (CBCT) that could impact treatment and help interventional radiologists for treatment planning, diagnosis and for assessing the technical feasibility during PAE, mitigating the risk of nontarget embolization and suggesting clinical outcomes. Qualitative and quantitative clinical pre- and post-treatment values will be compared, to reach the best possible results.

Computed tomographic features of the prostatic gland in neutered and intact dogs

BACKGROUND

Aim was to investigate age-dependent changes in the prostate of castrated dogs in computed tomographic (CT) examination. Thirty-six canine prostates were evaluated in pre- and post-contrast CT scans. Dogs were divided in groups with homogenous prostatic tissue (25/36) and with tissue alterations (11/36). Prostatic attenuation in Hounsfield Units (HU) and prostatic size were measured and a ratio of the prostatic size to the sixth lumbar vertebra was calculated. Additionally, the CT images of the prostate were compared with ultrasound examination.

RESULTS

In pre-contrast CT scans no significant differences were found in prostatic size between homogenous and altered prostatic tissue groups whereas prostatic attenuation differed significantly in post-contrast CT between these groups. The homogenous tissue pattern of homogeneous prostates could be confirmed in CT images and in ultrasound examination. Concerning prostates with alterations, the results differed between ultrasound and CT examination in four cases of 11 dogs with tissue alterations.

CONCLUSIONS

CT is beneficial to examine the prostate of castrated dogs. The prostatic attenuation is characteristic for the prostatic morphology, which can vary due to ageing processes. Differences in attenuation and size can be found between prostates of castrated and intact dogs. Using contrast agent, CT can visualize prostatic alterations, which were not seen in ultrasound. The presented results should be considered preliminary until a study with larger sample size and histologic examination of the prostates is performed.

Contrast-Enhanced Ultrasonography for the Early Evaluation of Prostate Artery Embolization

AIM

To prospectively evaluate the feasibility and reproducibility of the semiquantitative measurement of the unenhanced area of the prostate by trans-abdominal contrast-enhanced ultrasound (CEUS) performed immediately after prostate artery embolization (PAE) as a prognostic factor of success.

METHODS

Thirty-nine patients with PAE were prospectively included. They all underwent pre- and post-PAE trans-abdominal prostate CEUS. Two readers independently evaluated the pre- and post-PAE unenhanced area using a semiquantitative method: unenhanced areas were measured on 3 different slices (basis, middle, and apex) and reported to the whole prostate area. The mean of the three measures was reported semiquantitatively in classes of ten percent and quartiles. We evaluated correlation with clinical success, at 3 months after PAE, defined as a > 25% reduction in the International Prostatic Symptoms Score and a Quality of life < 3.

RESULTS

Twenty-three patients who had bilateral PAE were analyzed. Pre-PAE trans-abdominal prostate CEUS showed visible early and marked enhancement of the entire prostate in all patients. After PAE, all patients had a semiquantitatively measured unenhanced area > 25%. The semiquantitative measurement was found to be highly reproducible, with an interclass correlation > 0.8. No correlation was found between the area of unenhanced tissue and clinical success evaluated at 3 months.

CONCLUSION

Trans-abdominal prostate CEUS performed early after PAE provides reproducible results and is a valuable tool to evaluate unenhanced areas of the prostate.

LEVEL OF EVIDENCE

3, local non random sample.

Four-Year Impact of Voiding and Storage Symptoms in Patients with Benign Prostatic Hyperplasia Treated with Prostatic Artery Embolization

PURPOSE

To study the subscore improvement in International Prostate Symptom Scores (IPSS) after prostatic artery embolization (PAE).

MATERIALS AND METHODS

A single-center retrospective study was carried out with follow-up from December 2013 to July 2019 in 37 consecutive patients (66.0 ± 8.8 years old) who underwent PAE, comparing resultant scores before and after PAE. IPSS were divided into storage (IPSS-s) subscores and voiding (IPSS-v) subscores. The changes between IPSS-s and IPSS-v at 1, 3, 6, and 12 months' follow-up as well as the last follow-up were compared with baseline scores. The changes in percentages of IPSS-s and IPSS-v and the changes in average IPSS-s-to-total IPSS ratios (IPSS-s/IPSS-t) and IPSS-v-to-IPSS-t ratios (IPSS-v/IPSS-t) were also analyzed.

RESULTS

In the study population, consisting of 37 patients, IPSS-t significantly decreased from 16.5 ± 7.2 at baseline to 8.3 ± 5.7 at the last follow-up (4 years later) (P < .0001). Additionally, the changes in IPSS-v symptoms were greater than the changes in IPSS-s symptoms at 1, 3, 6, and 12 months' follow-up, reaching a statistical significance at 6 months with a decrease of 72.9% ± 42.4% for IPSS-v and a decrease of 50.1% ± 52.2% for IPSS-s (P = .009).

CONCLUSIONS

PAE can successfully reduce both IPSS-s and IPSS-v with predominant IPSS-v reduction. The improvements in both subscores were sustained for up to 4 years of follow-up.

Effect of Median Lobe Enlargement on Early Prostatic Artery Embolization Outcomes

PURPOSE

To evaluate outcomes after prostatic artery embolization (PAE) in patients with severe intravesical prostatic protrusion (IPP).

MATERIALS AND METHODS

This was a retrospective, single health system, 2-hospital study from April 2015 to December 2018 of 54 patients who underwent elective PAE procedures (age mean 67.5 years; standard deviation [SD] 8.5). The cohort had a mean ellipsoid prostate volume of 100.1 cm³ (SD 56.7), a mean baseline International Prostate Symptom Score (IPSS) of 18.7 (SD 8.2), a mean baseline quality of life (QOL) score of 4.1 (SD 1.4), and a median follow-up of 38 days (range 10-656 days). Outcomes including IPSS and QOL score reduction (where a lower QOL score indicates an improvement in QOL), and clinical success were compared between severe (≥10 mm) and nonsevere (<10 mm) IPP patients. A linear regression model was used to examine the impact of IPP on these outcomes.

RESULTS

No significant differences in patient characteristics were found between nonsevere (n = 17) and severe (n = 37) IPP patients. Both cohorts showed IPSS reduction (nonsevere 6.0, P = .0397; severe 8.2, P < .0001) and QOL score reduction (nonsevere 1.0, P = .102; severe 2.0, P < .0001). No significant differences in IPSS or QOL score reduction were found between the cohorts (P = .431 and P = .127). Linear regression found that baseline IPP was not a significant contributor to the outcomes (IPSS: R² = .5, P < .0001; IPP: P = .702; QOL: R² = .5, P = .0003; IPP: P = .108).

CONCLUSIONS

There were no significant differences in early outcomes in PAE between patients with severe and nonsevere IPP.

Ultrasonography of the Adult Male Urinary Tract for Urinary Functional Testing

The incidence of clinical benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS) is increasing due to the aging population, resulting in a significant economic and quality of life burden. Transgenic and other mouse models have been developed to recreate various aspects of this multifactorial disease; however, methods to accurately quantitate urinary dysfunction and the effectiveness of new therapeutic options are lacking. Here, we describe a method that can be used to measure bladder volume and detrusor wall thickness, urinary velocity, void volume and void duration, and urethral diameter. This would allow for the evaluation of disease progression and treatment efficacy over time. Mice were anesthetized with isoflurane, and the bladder was visualized by ultrasound. For non-contrast imaging, a 3D image was taken of the bladder to calculate volume and evaluate shape; the bladder wall thickness was measured from this image. For contrast-enhanced imaging, a catheter was placed through the dome of the bladder using a 27-gauge needle connected to a syringe by PE50 tubing. A bolus of 0.5 mL of contrast was infused into the bladder until a urination event occurred. Urethral diameter was determined at the point of the Doppler velocity sample window during the first voiding event. Velocity was measured for each subsequent event yielding a flow rate. In conclusion, high frequency ultrasound proved to be an effective method for assessing bladder and urethral measurements during urinary function in mice. This technique may be useful in the assessment of novel therapies for BPH/LUTS in an experimental setting.

Precision and accuracy of magnetic resonance imaging for lobar classification of benign prostatic hyperplasia

PURPOSE

To validate the application of a magnetic resonance imaging (MRI)-based lobar classification of benign prostatic hyperplasia (BPH) for use in research and clinical management.

METHODS

Two radiologists with 5 and 11 years post-fellowship experience were trained in the lobar classification of BPH using an internally developed atlas of prostate anatomy with example MRI images edited by a third senior radiologist designated as the "administrator" of the study. A study population of 140 patients referred to a tertiary academic medical center with known or suspected prostate cancer was selected by the administrator to test the interrater reliability (IRR; precision) of the classification as well as accuracy of the two readers compared to the administrator as the "gold" standard. The intrarater reliability of repeat readings of the administrator was also examined. Percentage of agreement, proportion of agreement, and Cohen's κ were applied. This was a retrospective IRB-approved study.

RESULTS

IRR (precision) between the two interpreting radiologists was 64% agreement, corresponding to unweighted κ of 0.52. Composite proportion of agreement across all BPH types (categories) for interpreting radiologists was 0.67. Observer accuracy was 62% agreement, unweighted κ 0.49, for observer 1 and 67%, unweighted κ 0.58, for observer 2. Intrarater reliability for the administrator was 87% agreement, unweighted κ 0.81 with composite proportion of agreement across all categories of 0.87.

CONCLUSIONS

MRI lobar classification of BPH is a reproducible and reliable tool for research and clinical applications.

Effects of Prostatic Artery Embolization on the Dynamic Component of Benign Prostate Hyperplasia as Assessed by Ultrasound Elastography: A Pilot Series

PURPOSE

To determine the effects of prostatic artery embolization (PAE) on prostatic elasticity as assessed by Ultrasound Elastography (US-E), as well as to describe the feasibility and role of US-E as a novel tool in both pre- and post-PAE evaluation.

MATERIALS AND METHODS

This is a prospective, single-center investigation that included eight patients undergoing PAE for treatment of lower urinary tract symptoms (LUTS) attributed to benign prostate hyperplasia (BPH). Baseline and 3-month follow-up evaluations were performed and included prostate-specific antigen (PSA), uroflowmetry, pelvic magnetic resonance imaging and clinical assessment using the International Prostate Symptom Score (IPSS) questionnaire and the IPSS-Quality of life (QoL) item. US-E with measurement of the prostatic Elastic Modulus (EM) was performed before PAE and at 1-month follow-up.

RESULTS

After PAE, US-E showed a significant reduction of prostatic EM as assessed in kPa (33.14 vs. 47.24, - 29.8%, p = 0.002) and in m/s (3.75 vs. 4.63, - 19.0%, p < 0.001). Also, the transitional/peripheral zone ratio was significantly reduced by 45.36% (0.53 vs. 0.97, p < 0.05). All eight patients presented with significant LUTS improvement after PAE (p < 0.05 for IPSS, QoL, prostate volume, peak urinary flow rate and PSA).

CONCLUSIONS

Findings described in this study suggest that PAE significantly reduces prostatic EM, leading to a positive effect on BPH dynamic component related to prostatic elasticity. Also, it features US-E as an additional tool for pre- and post-PAE evaluation, describing a novel indication for this technology.

MR imaging findings of the prostate gland following prostate artery embolization: results from a prospective phase 2 study

PURPOSE

To assess changes in imaging and volume characteristics of the prostate gland by magnetic resonance (MR) following prostatic artery embolization (PAE) for benign prostate hyperplasia.

METHODS

With IRB approval, we analyzed prospectively acquired MR data of PAE patients at baseline and 6-month following treatment from 2015 to 2017. We reviewed prostate MRs looking for sequelae of embolization [changes in signal intensity and/or enhancement, infection/inflammation, infarction, edema, and change in intravesical prostatic protrusion (IPP)]. We calculated the total volume (TV) and central gland volumes (CGV) using DynaCAD^® and measured change in volumes. Analyses were performed using SPSS with p < 0.05 considered significant.

RESULTS

Forty-three patients (n = 43) met our inclusion criteria. 93% (30/43) and 100% (43/43) showed a decrease in TV and CGV at 6-months respectively. At baseline, median TV was 86 cc (range 29.4-232) and median CGV was 54.4 cc (range 12.9-165.5). Median decrease in TV was 18.2% (CI 13.3-27.2) (p = 0.0001) and median decrease in CGV was 26.7% (CI 20.4-35.9) (p = 0.0001). Thirty-seven percent (16/43) of patients had IPP at baseline; 100% showed a decrease in size of median lobe at follow-up. At 6-month follow-up, 33% (14/43) showed imaging features of infarction, 79% (34/43) had decrease in T2-signal intensity, and 51% (22/43) showed a decrease in enhancement. None had edema, peri-prostatic fat changes or infection/inflammation.

CONCLUSION

PAE causes a statistically significant reduction in the TV and CGV. There is also a reduction of the degree of IPP. Non-specific findings of infarction, decrease in T2-signal, and enhancement were also seen.

[Prostate artery embolisation is a new treatment for prostate disease]

Prostate artery embolisation (PAE) is a new minimally in-vasive treatment for prostate disease. Recent studies have shown, that PAE may be an alternative to transurethral resection of the prostate (TURP), and it reduces the prostate volume by 40%. The reduction in symptom score is com-parable to that of TURP, and only few major complications have been reported. The purpose of this narrative review is to provide a brief overview of the current literature on PAE.

[Prognostic significance of prostate-specific antigen in defining indications for initial prostate biopsy]

Currently, prostate biopsy remains the main method used to diagnose prostate cancer (PCa). The indication for the procedure is an elevated level of the serum level of the total prostate-specific antigen (PSA). However, the PSA test is organ- but not cancer-specific, and patients may undergo an unnecessary biopsy, which is an invasive procedure associated with a risk of complications. Additional tests have been developed aimed to improve the diagnostic performance of PSA for detecting PCa. They include PSA derivatives such as free PSA fraction, -2proPSA, PSA density, PHI and the free /total PSA fraction.

AIM

To investigate the diagnostic accuracy of PSA and its derivatives in detecting benign and malignant diseases of the prostate after an initial prostate biopsy.

MATERIALS AND METHODS

The current study analyzed 65 initial biopsies performed due to an elevated serum PSA level and compared them with the results of extended PSA testing with the use of PSA derivatives.

RESULTS

The histological findings consistent with PCa were found in about 30% of initial biopsies performed due to elevated serum levels of total PSA. The incidence of histologically confirmed PCa increased with age, and 70-79 year old men were more likely to have it than 60-69 years old patients. PSA density in 85% of PCa cases exceeded that for benign prostatic hyperplasia (BPH). In all PCa patients, PHI and free /total PSA fraction were greater than 25 and less than 0.15, respectively. In most patients with BPH, the PHI and free /total PSA fraction did not exceed 25 and were greater than 0.15.

CONCLUSIONS

1. Initial biopsy triggered by elevated serum level of total PSA allows detection of PCa in about 30% of cases. 2. The age of 60 years and older should be regarded as a risk factor for PCa. The probability of malignant transformation of prostate epithelial cells in men over 70 years of age is greater than in 60-69-year-olds. 3. The density of PSA in men with morphologically verified PCa is statistically significantly greater than that in men with BPH and the threshold value in 85% of cases. 4. Determination of PHI and free/total PSA fraction can improve the accuracy of predicting malignant lesions of the prostate and adjust the indications for histological examination, reduce the number of unnecessary biopsies. 5. When defining indications for initial prostate biopsy in cases with serum PSA varying from 2 to 10 ng/ml, PSA derivatives should be used, including PSA density, prostate health index, and the free /total PSA fraction.

Early post-interventional sonographic evaluation of prostatic artery embolization. A promising role for contrast-enhanced ultrasonography (CEUS)

AIMS

To assess the feasibility, findings and potential value of early post-interventional, contrast-enhanced ultrasonographic (CEUS) study of prostate artery embolization (PAE).

MATERIAL AND METHODS

Fourteen patients treated with PAE for symptomatic benign prostatic hyperplasia were prospectively included in the study. Sonographic evaluation of the prostate included: 1) baseline transabdominal and transrectal CEUS (ta-CEUS and tr-CEUS, respectively) 1-3 days prior to PAE; 2) early post PAE CEUS, with ta-CEUS immediately post PAE and tr-CEUS 3 days post PAE; and 3) follow-up with ta-CEUS and tr-CEUS 3 months post PAE. A brief unenhanced US study preceded each CEUS. Post-therapeutic changes in size, echogenicity and enhancement of the prostate were recorded and were correlated with clinical outcomes.

RESULTS

PAE resulted in clinical success in 11/14 patients (78.5%). All sonographic studies were technically adequate, with the exception of ta-CEUS immediately post PAE in 2/14 (14.2%) patients. CEUS studies immediately post PAE and 3 days post PAE showed non-enhancing, welldefined infarctions of the prostate in 10/14 patients (71.4%). There was a strong correlation between ta-CEUS immediately post PAE and tr-CEUS 3 days post PAE regarding the measurements of prostatic infarctions (r =0.98, p< 0.01). The presence of infarctions on early post PAE CEUS was associated with clinical success (p=0.01) and their extent correlated with the degree of prostate shrinkage on 3-month follow-up (r=0.84, p<0.05). The 3 cases of failed PAE showed no infarctions and no prostate shrinkage.

CONCLUSIONS

Early post-interventional CEUS of PAE is feasible and may have clinical and prognostic value.