The influence of prostate volume on prostate cancer detection using a combined approach of contrast-enhanced ultrasonography-targeted and systematic grey-scale biopsy

68Ga-PSMA PET/CT-based multivariate model for highly accurate and noninvasive diagnosis of clinically significant prostate cancer in the PSA gray zone

BACKGROUND

The prostate-specific antigen (PSA) has been widely used in screening and early diagnosis of prostate cancer (PCa). However, in the PSA grey zone of 4-10 ng/ml, the sensitivity and specificity for diagnosing PCa are limited, resulting in considerable number of unnecessary and invasive prostate biopsies, which may lead to potential overdiagnosis and overtreatment. We aimed to predict clinically significant PCa (CSPCa) by combining the maximal standardized uptake value (SUVmax) based on 68Ga‑PSMA PET/CT and clinical indicators in men with gray zone PSA levels.

METHODS

81 patients with suspected PCa based on increased serum total PSA (TPSA) levels of 4 - 10 ng/mL who underwent transrectal ultrasound/magnetic resonance imaging (MRI)/PET fusion-guided biopsy were enrolled. Among them, patients confirmed by histopathology were divided into the CSPCa group and the non-CSPCa group, and data on PSA concentration, prostate volume (PV), PSA density (PSAD), free PSA (FPSA)/TPSA, Prostate Imaging-Reporting and Data System version 2.1 (PI-RADS v2.1) score, 68Ga-PSMA PET/CT imaging evaluation results and SUVmax were compared. Multivariate logistic regression analysis was performed to identify the independent predictors for CSPCa, thereby establishing a predictive model based on SUVmax that was evaluated by analyzing the receiver operating characteristic (ROC) curve and decision curve analysis.

RESULTS

Compared to non-CSPCa, CSPCa patients had smaller PVs (median, 31.40 mL), lower FPSA/TPSA (median, 0.12), larger PSADs (median, 0.21 ng/mL2) and higher PI-RADS scores (P < 0.05). The prediction model comprising 68Ga-PSMA PET/CT maximal standardized uptake value, PV and FPSA/TPSA had the highest AUC of 0.927 compared with that of other predictors alone (AUCs of 0.585 for PSA, 0.652 for mpMRI and 0.850 for 68Ga-PSMA PET/CT). The diagnostic sensitivity and specificity of the prediction model were 86.21% and 86.54%, respectively.

CONCLUSION

Given the low diagnostic accuracy of regular PSA tests, a new prediction model based on the 68Ga-PSMA PET/CT SUVmax, PV and FPSA/TPSA was developed and validated, and this model could provide a more satisfactory predictive accuracy for CSPCa. This study provides a noninvasive prediction model with high accuracy for the diagnosis of CSPCa in the PSA gray zone, thus may be better avoiding unnecessary biopsy procedures.

Comparison of MRI/US Fusion Targeted Biopsy and Systematic Biopsy in Biopsy-Naïve Prostate Patients with Elevated Prostate-Specific Antigen: A Diagnostic Study

Purpose

This study aimed to compare the detection rate of prostate cancer (PCa) between targeted biopsy and systematic biopsy.

Patients and Methods

A total of 671 patients who underwent both targeted biopsy and systematic biopsy were included in this study. The stratified analysis was conducted based on Prostate Imaging Reporting and Data System (PIRADS) scores, region of interest load (ROI-load).

Results

There was no statistical difference in the detection rate of PCa patients between systematic biopsy and targeted biopsy (44.41% vs 45.6%, P>0.05), while the detection rate of targeted biopsy in clinically significant PCa (csPCa) patients was slightly higher than that of systematic biopsy (40.83% vs 38.15%, P=0.033). Stratified analysis indicated that targeted biopsy was more advantageous in csPCa patients with PIRADS score ≥ 4 and ROI-load > 5%. The comparison of diagnostic sensitivity of systematic biopsy and targeted biopsy demonstrated that targeted biopsy was more sensitive than systematic biopsy to diagnose PCa (Z=2.110, P=0.035) at ROI-load ≤ 5%. In addition, ROI-load may be a better targeted biopsy indicator than ROI diameter for the diagnosis of PCa (Z=2.168, P=0.030).

Conclusion

MRI/US fusion targeted biopsy may be more suitable for PCa detection than systematic biopsy in patients with low ROI-load.

[Sonography of the prostate : Relevance for urologists in daily clinical routine]

Despite the continuous technical progress regarding the transrectal ultrasonography of the prostate (TRUS) and its successful use in combination with magnetic resonance imaging (MRI) in MRI-targeted biopsy, there is no radiologic modality being able to rule out clinically significant prostate cancer without the need of systematic biopsy. In the past few years, TRUS regained more attention due to the development of high frequency ultrasound as well as the combination of different ultrasonic modalities like shear wave elastography and contrast-enhanced sonography (CEUS). Currently, multiparametric MRI (mpMRI)-targeted biopsy shows the best results concerning detection rates, sensitivity and specificity of clinically significant prostate cancer compared to systematic biopsy. In the future, transperineal biopsy is probably going to increasingly replace the transrectal biopsy approach. For both approaches, transrectal ultrasonography is necessary to display the prostate and to detect suspicious lesions. Therefore future improvements in transrectal ultrasonography can be expected.

Any Correlation Between Prostate Volume and Incidence of Prostate Cancer: A Review of Reported Data for the Last Thirty Years

PURPOSE

Prostate cancer (PCa) is the most common non-skin cancer in men worldwide and more than 80% of men with PCa also have histo-anatomical findings of benign prostate hyperplasia (BPH). It is well documented that BPH develops in the transition zone (TZ), whereas 80-85% of PCa originates in the peripheral zone (PZ) of the prostate. Possible causal links between both disease entities are controversially discussed in the current literature. Some studies have reported that larger prostates have a decreased incidence of PCa compared to smaller prostates. The purpose of this systematic review is to comprehensively summarize studies analyzing any association between prostate gland volume and incidence of PCa.

METHODS

A thorough literature review was performed between 01.01.1990 through 02.28.2020 using PubMed and applying the "PRISMA" guidelines. Inclusion and exclusion criteria were defined.

RESULTS

Our systematic review found 41 articles reporting an inverse (negative) relationship between prostate gland volume and incidence of prostate cancer. Sample sizes ranged from 114 to 6692 patients in these single institutional and multi-institutional studies. Thirty-nine (95%) of the 41 articles showed a statistically significant inverse relationship. In our search, no study was found showing a positive correlation between BPH size and the incidence of PCa.

CONCLUSION

To our knowledge, this is the first systematic review on the important clinical question of interaction between prostate size and the incidence of PCa. The results are demonstrating an inverse relationship, and therefore reveal strong evidence that large prostates may be protective of PCa when compared to smaller prostates.

Biparametric prostate MRI and clinical indicators predict clinically significant prostate cancer in men with "gray zone" PSA levels

PURPOSE

To predict clinically significant prostate cancer (cs-PCa) by combining the Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) score based on biparametric magnetic resonance imaging (bp-MRI) and clinical indicators in men with prostate-specific antigen (PSA) levels in the gray zone of 4-10 ng/mL.

METHOD

We retrospectively analyzed 364 patients with elevated PSA levels in the gray zone who had pathologically confirmed disease and had undergone MRI examinations from January 2015 to October 2019; a training group (n = 255) and validation group (n = 109) were randomly established. Multivariate logistic regression analysis of the training group was performed to identify the independent predictors for cs-PCa, thereby establishing a predictive model that was evaluated in the training and validation groups by analyzing the receiver operating characteristic (ROC) curve.

RESULTS

In the training group, the PI-RADS v2 score and prostate volume (PV) were independent predictors of cs-PCa (P < 0.05). The prediction model comprising the PI-RADS v2 score and PV had a larger AUC than the other predictors alone in the training group. The diagnostic sensitivity and specificity of the prediction model were 84.1 % and 83.4 %, respectively. The prediction model was indicated to have better predictive performance in the validation group.

CONCLUSIONS

The prediction model exhibits a satisfactory predictive value for cs-PCa in men with PSA levels in the gray zone. PI-RADS v2 is the strongest univariate predictor for the detection of cs-PCa in men with PSA in the gray zone, but combining this with the PV can provide superior predictive ability.

Impact of a novel ultrasound microvascular imaging and elastography on prostate cancer classification

Background

This study was aimed to compare the sensitivity of transrectal ultrasound (TRUS) guided systematic biopsy (TRUS-SB), superb microvascular imaging guided targeted biopsy (SMI-TB), and elastography ultrasound guided targeted biopsy (EU-TB) in detecting prostate cancer (PCa).

Methods

One hundred and eighty-four patients with suspicious PCa were randomly divided into two groups, SMI-TB group (n=92) and EU-TB group (n=92). All the patients received a 2-core SMI-TB or a 2-core EU-TB before receiving a 12-core TRU-SB depending on the group. The 2-core SMI-TB was conducted at the most increased vascularity areas rated by a radiologist on a semi-quantitative criterion. The 2-core EU-TB was performed at the dark blue areas that identified as suspicious areas. The PCa detection rate was compared among TRUS-SB, SMI-TB, and EU-TB in the total population and in two groups.

Results

PCa was detected in 65 out of 184 patients. The SMI-TB group patients received 1,272 cores in total with a positive rate of 23.81% (40/168) for SMI-TB cores and 4.17% (46/1,104) for TRUS-SB cores. The EU-TB group patients received a total of 1,262 cores with a positive rate of 31.01% (49/158) for EU-TB cores and 5.34% (59/1,104) for TRUS-SB cores. Targeted cores (27.30%, 89/326) achieved significantly higher sensitivity in PCa detection than systematic cores (4.76%, 105/2,208) (SMI-TB vs. TRUS-SB: OR 7.188, P<0.001; EU-TB vs. TRUS-SB: OR 7.962, P<0.001).

Conclusions

Superb microvascular imaging and elastography ultrasound guided targeted biopsy may result in higher prostate cancer detection rate as adjunct to gray-scale ultrasound guided systematic biopsy. However, targeted biopsy alone is not sufficient to detect PCa, compared with systematic biopsy.

Evaluation of PSA-age volume score in predicting prostate cancer in Chinese population

This study was performed to evaluate prostate-specific antigen-age volume (PSA-AV) scores in predicting prostate cancer (PCa) in a Chinese biopsy population. A total of 2355 men who underwent initial prostate biopsy from January 2006 to November 2015 in Huashan Hospital were recruited in the current study. The PSA-AV scores were calculated and assessed together with PSA and PSA density (PSAD) retrospectively. Among 2133 patients included in the analysis, 947 (44.4%) were diagnosed with PCa. The mean age, PSA, and positive rates of digital rectal examination result and transrectal ultrasound result were statistically higher in men diagnosed with PCa (all P < 0.05). The values of area under the receiver operating characteristic curves (AUCs) of PSAD and PSA-AV were 0.864 and 0.851, respectively, in predicting PCa in the entire population, both performed better than PSA (AUC = 0.805; P < 0.05). The superiority of PSAD and PSA-AV was more obvious in subgroup with PSA ranging from 2.0 ng ml^-1 to 20.0 ng ml^-1. A PSA-AV score of 400 had a sensitivity and specificity of 93.7% and 40.0%, respectively. In conclusion, the PSA-AV score performed equally with PSAD and was better than PSA in predicting PCa. This indicated that PSA-AV score could be a useful tool for predicting PCa in Chinese population.

Prediction of Prostate Cancer: External Validation of the ERSPC Risk Calculator in a Contemporary Dutch Clinical Cohort

BACKGROUND

The validity of prediction models needs external validation to assess their value beyond the original development setting.

OBJECTIVE

To report the diagnostic accuracy of the European Randomized Study of Screening for Prostate Cancer (ERSPC) risk calculator (RC)3 and RC4 in a contemporary Dutch clinical cohort.

DESIGN, SETTING, AND PARTICIPANTS

We retrospectively identified all men who underwent prostate biopsy (PBx) in the Jeroen Bosch Hospital, The Netherlands, between 2007 and 2016. Patients were included if they met ERSPC RC requirements of age (50-80 yr), prostate-specific antigen (PSA) (0.4-50 ng/ml), and prostate volume (10-150ml). The probability of a positive biopsy for prostate cancer (PCa) and significant PCa (Gleason score ≥7 and/or higher than T2b) were calculated and compared with PBx pathology results.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Evaluation was performed by calibration, discrimination, and clinical usefulness using calibration plots, area under the receiver operating characteristic curves (AUCs), and decision curve analyses (DCAs), respectively.

RESULTS AND LIMITATIONS

A total of 2270 PBx sessions were eligible for final analysis. Discriminative ability of RC3 (AUC) was 0.78 and 0.90 for any PCa and significant PCa, respectively. For RC4 the calculated AUCs were 0.62 (any PCa) and 0.76 (significant PCa). The calibration plots of RC3 showed good results for both any PCa risk and significant PCa risk. In the repeat PBx group, RC4 tended to underestimate outcomes for PCa and showed moderate calibration for significant PCa. DCA showed an overall net benefit compared with PSA and digital rectal examination (DRE) alone. Limitations of this study are its retrospective single-institution design, retrospectively assessed DRE outcomes, no time restrictions between the first and repeat biopsy sessions, and no anterior sampling in the repeat PBx protocol.

CONCLUSIONS

The ERSPC RCs performed well in a contemporary clinical setting. Most pronounced in the biopsy-naive group, both RCs should be favoured over a PSA plus DRE-based stratification in the decision whether or not to perform PBx.

PATIENT SUMMARY

We looked at the ability of the existing European Randomized Study of Screening for Prostate Cancer risk calculator (RC), using different clinical data to predict the presence of prostate cancer in Dutch men. The RC performed well and should be favoured in the decision of whether or not to perform prostate biopsies over the conventional diagnostic pathway.

[Sonographic imaging of the prostate]

Accurate identification of the location of carcinoma in the prostate is essential for long-term therapeutic success, in particular for minimally invasive procedures. In recent years many new positive study results for prostate imaging have been reported which must be compared and evaluated and previous conservative assessments may need to be re-evaluated. In addition, combinations of different imaging techniques are increasingly being used in daily clinical routine. Due to technical advancements in sonographic imaging, such as elastography and contrast-enhanced ultrasound (CEUS), the detection rate of prostate cancer can be increased. An overview of the different imaging modalities and current literature are presented in this article.

The influence of prostate volume on cancer detection in the Chinese population

In western populations, prostate volume (PV) has been proven to be one of the strongest predictors of detecting prostate cancer (PCa) in biopsies. We performed this study in a biopsy cohort, to evaluate associations among the prostate volume, prostate-specific antigen (PSA) and PCa detection in the Chinese population. Between the years, 2007–13, 1486 men underwent prostate biopsy at Huashan Hospital, Fudan University, Shanghai, China. The study population was divided into two groups for analysis according to total PSA (tPSA) range (4 ng ml⁻¹ < tPSA ≤20 ng ml⁻¹ and tPSA > 20 ng ml⁻¹). PV, age, tPSA, digital rectal examination (DRE) and transrectal ultrasound (TRUS) results were also included in the analysis. Although the positive biopsy rates decreased in both tPSA range groups, the downtrend was more pronounced in the 4 ng ml⁻¹ < tPSA ≤20 ng ml⁻¹ group; therefore, we focused on 853 men in this group with increasing PV. In multivariate logistic regression analysis, only DRE was found to be associated with PCa in four PV groups (P < 0.05) and tPSA did not show a good predictive ability when PV exceeded 50 ml (P > 0.05). Further, it may suggest that with increasing PV, the cancer detection rate decreased in men with different tPSA, DRE and TRUS nodule statuses (all P values for trends were <0.001). Our study indicates that in tPSA ranging from 4 to 20 ng ml⁻¹, the use of PV ranges of 0–35 ml, 35–50 ml and > 50 ml might be taken into consideration for the biopsy decision-making in the Chinese population.

Prostate volume as an independent predictor of prostate cancer in men with PSA of 10-50 ng ml(-1)

Prostate volume (PV) has been shown to be associated with prostate cancer (PCa) detection rates in men with a prostate-specific antigen (PSA) in the 'grey zone' (2.0-10.0 ng ml(-1)). However, the PSA 'grey zone' in Asian men should be higher because the incidence of PCa in Asian men is relatively low. Therefore, we evaluated the association between PV and PCa detection rates in men with PSAs measuring 10-50 ng ml(-1). Men who underwent a 13-core prostatic biopsy with PV documentation participated in the study. A multivariate stepwise regression was used to evaluate whether the PV at time of prostate biopsy could predict the risk of PCa. The rates of PCa among men in different PSA ranges, stratified by PV medians (<60 and ≥60 ml), were calculated. There were 261 men included in the final analysis. PV was the strongest predictor of PCa risk (odds ratio, 0.02; P<0.001) compared to other variables. The PCa rates in men with PVs measuring <60 and ≥60 ml in the 10-19.9 ng ml(-1) PSA group were 40.6% and 15.1%, respectively, while the rates for men with PSAs measuring 20-50 ng ml(-1) were 65.1% and 26.8%. PV is an independent predictor of PCa in men with PSA measuring 10-50 ng ml(-1). In clinical practice, particularly for those countries with lower incidences of PCa, PV should be considered when counselling patients with PSAs measuring 10-50 ng ml(-1) regarding their PCa risks.

Diagnostic performance of contrast enhanced ultrasound in patients with prostate cancer: a meta-analysis

RATIONALE AND OBJECTIVES

We aimed to do a meta-analysis of the existing literature to assess the accuracy of prostate cancer (PCa) studies that use contrast-enhanced ultrasound (CEUS) as a diagnostic tool.

MATERIALS AND METHODS

The MEDLINE, EMBASE, and Cochrane Library databases were searched for relevant original articles published up to August 2012. Characteristics of Included studies were recorded. Methodological quality was assessed by using the quality assessment of diagnostic studies tool. Pooled weighted estimates of diagnostic odds ratio (DOR), sensitivity, specificity, and positive and negative likelihood ratio (LR) were calculated. A summary receiver operator characteristic (SROC) curve was constructed to calculate the area under the curve (AUC). Publication bias analysis was also performed.

RESULTS

Sixteen studies (2624 patients) were included in the meta-analysis. Various contrast agents and imaging modes were applied. The independent random-effects summary showed a variation in diagnostic values. The summary estimates of sensitivity, specificity, and DOR were 0.70, 0.74, and 9.09, respectively. The weighted positive and negative LR were 2.81 and 0.35, with statistically significant between-study heterogeneity (P < .001). Sensitivity was better in positive patient studies than positive biopsy cores ones (0.78 vs. 0.64). SROC plot displayed value for AUC (0.82). Begg's test (P = .822) and Egger's test (P = .198) did not show evidence of publication bias.

CONCLUSION

CEUS is a promising tool in the detection of PCa, but it cannot completely replace systematic biopsy under the present circumstances. It is necessary to standardize imaging techniques, contrast agents and diagnostic criteria. Large samples, multi-center studies and high-quality prospective trials are necessary to assess its clinical value.

The adjunctive use of power Doppler imaging in the preoperative assessment of prostate cancer

OBJECTIVE

To determine if the adjunctive use of power Doppler imaging (PDI) could provide prognostic utility in the treatment of prostate cancer, as an accurate prediction of the clinical behaviour of prostate cancer is important to determine appropriate treatment.

PATIENTS AND METHODS

Most centres rely on a digital rectal examination or transrectal ultrasonography (TRUS) to assess the clinical stage of patients. In 2002, we began using a standardized form to evaluate TRUS findings and PDI findings. We compared preoperative clinical findings with those from pathological analysis of 620 radical prostatectomy specimens from 2002 to 2007.

RESULTS

The mean (sd) patient age was 58 (6.6) years with a mean prostate-specific antigen (PSA) level of 7.0 (4.5) ng/mL. Of the 620 specimens 157 (25.3%) had evidence of extracapsular extension on pathological evaluation; 443 (71.5%) men had a hypervascular lesion seen on TRUS, while 177 (28.5%) patients had none. There was no difference in preoperative PSA level, grade or stage of tumour. Furthermore, rates of biochemical recurrence or secondary treatment did not differ based on PDI findings. As a tool to help locate prostate tumours, PDI improved the specificity of TRUS but did not improve the overall accuracy or sensitivity.

CONCLUSION

PDI provides little prognostic utility to assess risk in prostate cancer. However, PDI might improve the specificity of TRUS in identifying prostate tumours and could have a role in image guidance for focal therapy of prostate cancer.