Does prostate HistoScanning™ play a role in detecting prostate cancer in routine clinical practice? Results from three independent studies

Application of Multiple Ultrasonic Techniques in the Diagnosis of Prostate Cancer

Methods for diagnosing prostate cancer (PCa) are developing in the direction of imaging. Advanced ultrasound examination modes include micro-Doppler, computerized-transrectal ultrasound, elastography, contrast-enhanced ultrasound and microultrasound. When two or more of these modes are used in PCa diagnosis, the combined technique is called multiparameter ultrasound (mp-US). Mp-US provides complementary information to multiparameter magnetic resonance imaging (mp-MRI) for diagnosing PCa. At present, no study has attempted to combine the characteristics of different ultrasound modes with advanced classification systems similar to the PIRADS system in mpMRI for the diagnosis of PCa. As an imaging method, mp-US has great potential in the diagnosis of PCa.

A systematic review and meta-analysis of Histoscanning™ in prostate cancer diagnostics

CONTEXT

The value of Histoscanning™ (HS) in prostate cancer (PCa) imaging is much debated, although it has been used in clinical practice for more than 10 years now.

OBJECTIVE

To summarize the data on HS from various PCa diagnostic perspectives to determine its potential.

MATERIALS AND METHODS

We performed a systematic search using 2 databases (Medline and Scopus) on the query "Histoscan*". The primary endpoint was HS accuracy. The secondary endpoints were: correlation of lesion volume by HS and histology, ability of HS to predict extracapsular extension or seminal vesicle invasion.

RESULTS

HS improved cancer detection rate "per core", OR = 16.37 (95% CI 13.2; 20.3), p < 0.0001, I² = 98% and "per patient", OR = 1.83 (95% CI 1.51; 2.21), p < 0.0001, I² = 95%. The pooled accuracy was markedly low: sensitivity - 0.2 (95% CI 0.19-0.21), specificity - 0.12 (0.11-0.13), AUC 0.12. 8 of 10 studiers showed no additional value for HS. The pooled accuracy with histology after RP was relatively better, yet still very low: sensitivity - 0.56 (95% CI 0.5-0.63), specificity - 0.23 (0.18-0.28), AUC 0.4. 9 of 12 studies did not show any benefit of HS.

CONCLUSION

This meta-analysis does not see the incremental value in comparing prostate Histoscanning with conventional TRUS in prostate cancer screening and targeted biopsy. HS proved to be slightly more accurate in predicting extracapsular extension on RP, but the available data does not allow us to draw any conclusions on its effectiveness in practice. Histoscanning is a modification of ultrasound for prostate cancer visualization. The available data suggest its low accuracy in screening and detecting of prostate cancer.

Artificial intelligence in multiparametric prostate cancer imaging with focus on deep-learning methods

Prostate cancer represents today the most typical example of a pathology whose diagnosis requires multiparametric imaging, a strategy where multiple imaging techniques are combined to reach an acceptable diagnostic performance. However, the reviewing, weighing and coupling of multiple images not only places additional burden on the radiologist, it also complicates the reviewing process. Prostate cancer imaging has therefore been an important target for the development of computer-aided diagnostic (CAD) tools. In this survey, we discuss the advances in CAD for prostate cancer over the last decades with special attention to the deep-learning techniques that have been designed in the last few years. Moreover, we elaborate and compare the methods employed to deliver the CAD output to the operator for further medical decision making.

Prostate Imaging Compared to Transperineal Ultrasound-guided biopsy for significant prostate cancer Risk Evaluation (PICTURE): a prospective cohort validating study assessing Prostate HistoScanning

BACKGROUND

Men with negative prostate biopsies or those diagnosed with low-risk or low-volume intermediate-risk prostate cancers often require a second prostate biopsy prior to a treatment decision. Prostate HistoScanning (PHS) is an ultrasound imaging test that might inform prostate biopsy in such men.

METHODS

PICTURE was a prospective, paired-cohort validating trial to assess the diagnostic accuracy of imaging in men requiring a further biopsy (clinicaltrials.gov, NCT01492270) (11 January 2012-29 January 2014). We enrolled 330 men who had undergone a prior TRUS biopsy but where diagnostic uncertainty remained. All eligible men underwent PHS and transperineal template prostate mapping (TTPM) biopsy (reference standard). Men were blinded to the imaging results until after undergoing TTPM biopsies. We primarily assessed the ability of PHS to rule out clinically significant prostate (negative predictive value [NPV] and sensitivity) for a target histological condition of Gleason ≥4+3 and/or a cancer core length (MCCL) ≥6 mm. We also assessed the role of visually estimated PHS-targeted biopsies.

RESULTS

Of the 330 men enrolled, 249 underwent both PHS and TTPM biopsy. Mean (SD) age was 62 (7) years, median (IQR) PSA 6.8 (4.98-9.50) ng/ml, median (IQR) number of previous biopsies 1 (1-2) and mean (SD) gland size 37 (15.5) ml. One hundred and forty six (59%) had no clinically significant cancer. PHS classified 174 (70%) as suspicious. Sensitivity was 70.3% (95% CI 59.8-79.5) and NPV 41.3% (95% CI 27.0-56.8). Specificity and positive predictive value (PPV) were 14.7% (95% CI 9.1-22.0) and 36.8% (95% CI 29.6-44.4), respectively. In all, 213/220 had PHS suspicious areas targeted with targeting sensitivity 13.6% (95% CI 7.3-22.6), specificity 97.6% (95% CI 93.1-99.5), NPV 61.6% (95% CI 54.5-68.4) and PPV 80.0% (95% CI 51.9-95.7).

CONCLUSIONS

PHS is not a useful test in men seeking risk stratification following initial prostate biopsy.

Ultrasound Elastography of the Prostate Using an Unconstrained Modulus Reconstruction Technique: A Pilot Clinical Study

A novel full-inversion-based technique for quantitative ultrasound elastography was investigated in a pilot clinical study on five patients for non-invasive detection and localization of prostate cancer and quantification of its extent. Conventional-frequency ultrasound images and radiofrequency (RF) data (~5 MHz) were collected during mechanical stimulation of the prostate using a transrectal ultrasound probe. Pre and post-compression RF data were used to construct the strain images. The Young's modulus (YM) images were subsequently reconstructed using the derived strain images and the stress distribution estimated iteratively using finite element (FE) analysis. Tumor regions determined based on the reconstructed YM images were compared to whole-mount histopathology images of radical prostatectomy specimens. Results indicated that tumors were significantly stiffer than the surrounding tissue, demonstrating a relative YM of 2.5 ± 0.8 compared to normal prostate tissue. The YM images had a good agreement with the histopathology images in terms of tumor location within the prostate. On average, 76% ± 28% of tumor regions detected based on the proposed method were inside respective tumor areas identified in the histopathology images. Results of a linear regression analysis demonstrated a good correlation between the disease extents estimated using the reconstructed YM images and those determined from whole-mount histopathology images (r² = 0.71). This pilot study demonstrates that the proposed method has a good potential for detection, localization and quantification of prostate cancer. The method can potentially be used for prostate needle biopsy guidance with the aim of decreasing the number of needle biopsies. The proposed technique utilizes conventional ultrasound imaging system only while no additional hardware attachment is required for mechanical stimulation or data acquisition. Therefore, the technique may be regarded as a non-invasive, low cost and potentially widely-available clinical tool for prostate cancer diagnosis.

Screening and Detection of Prostate Cancer-Review of Literature and Current Perspective

Screening of prostatic cancer is a matter of debate among uro-oncologist. With many new screening modalities like prostatic health index (PHI), 4K testing the role of screening has increased as one is able to stratify patients with serum prostate specific antigen level in a grey zone of 4-10 ng/ml and normal digital rectal examination into various risk groups, thus avoiding unnecessary biopsy which was the pitfalls of routine screening practice. PHI is better at predicting malignancy while 4K is better at predicting high-grade disease. This in combination with multiparametric MRI especially with prostate imaging reporting and data system score has made screening less difficult and more meaningful for a practising uro-oncologist.

A Review of Imaging Methods for Prostate Cancer Detection

Imaging is playing an increasingly important role in the detection of prostate cancer (PCa). This review summarizes the key imaging modalities-multiparametric ultrasound (US), multiparametric magnetic resonance imaging (MRI), MRI-US fusion imaging, and positron emission tomography (PET) imaging-used in the diagnosis and localization of PCa. Emphasis is laid on the biological and functional characteristics of tumors that rationalize the use of a specific imaging technique. Changes to anatomical architecture of tissue can be detected by anatomical grayscale US and T2-weighted MRI. Tumors are known to progress through angiogenesis-a fact exploited by Doppler and contrast-enhanced US and dynamic contrast-enhanced MRI. The increased cellular density of tumors is targeted by elastography and diffusion-weighted MRI. PET imaging employs several different radionuclides to target the metabolic and cellular activities during tumor growth. Results from studies using these various imaging techniques are discussed and compared.

Sextant-Specific Analysis of Detection and Tumor Volume by HistoScanning™

INTRODUCTION

Published results of HistoScanning™ (HS) for prostate cancer (PCa) diagnostics are inconsistent and their value remains unclear. We prospectively analyzed the detection rate and tumor volume concordance in PCa patients.

MATERIAL AND METHODS

Two hundred and eighty-two patients with biopsy-proven PCa scheduled for radical prostatectomy (RP) were included. All patients underwent ultrasonographical examination by HS prior to surgery. HS was evaluated compared to RP specimen as to (1) the prediction of overall tumor volume and (2) accuracy of HS in detection of PCa lesions larger than 0.2/0.5 ml, separated for each sextant. For each sextant, receiver operating characteristic (ROC)-analysis and area under the curve were determined. Sensitivity and specificity were calculated and visualized in ROC-curves.

RESULTS

HS tends to underestimate volume of cancerous lesions, particularly larger lesions >8 ml. Using a 0.2 ml detection threshold, specificity and sensitivity of HS were between 29-68% and 46-78%. For a 0.5 ml detection threshold, sextant-specific specificity increased to 59-92% and sensitivity decreased to 16-54%. Stratification according to pre-operational PSA values did not improve performance characteristics of HS.

CONCLUSIONS

Our results do not support a significant contribution of HS to PCa diagnostics.

Multiparametric ultrasound in the detection of prostate cancer: a systematic review

PURPOSE

To investigate the advances and clinical results of the different ultrasound modalities and the progress in combining them into multiparametric UltraSound (mpUS).

METHODS

A systematic literature search on mpUS and the different ultrasound modalities included: greyscale ultrasound, computerized transrectal ultrasound, Doppler and power Doppler techniques, dynamic contrast-enhanced ultrasound and (shear wave) elastography.

RESULTS

Limited research available on combining ultrasound modalities has presented improvement in diagnostic performance. The data of two studies suggest that even adding a lower performing ultrasound modality to a better performing modality using crude methods can already improve the sensitivity by 13-51 %. The different modalities detect different tumours. No study has tried to combine ultrasound modalities employing a system similar to the PIRADS system used for mpMRI or more advanced classifying algorithms.

CONCLUSION

Available evidence confirms that combining different ultrasound modalities significantly improves diagnostic performance.

A prospective comparative analysis of the accuracy of HistoScanning and multiparametric magnetic resonance imaging in the localization of prostate cancer among men undergoing radical prostatectomy

INTRODUCTION

There is increasing interest in using imaging in the detection and localization of prostate cancer (PCa). Both multiparametric magnetic resonance imaging (mpMRI) and HistoScanning (HS) have been independently evaluated in the detection and localization of PCa. We undertook a prospective, blinded comparison of mpMRI and HS for cancer localization among men undergoing radical prostatectomy.

METHODS

Following approval by the institutional review board, men scheduled to undergo radical prostatectomy, who had previously undergone mpMRI at our institution, were offered inclusion in the study. Those consenting underwent preoperative HS following induction of anesthesia; mpMRI, HS, and surgical step-section pathology were independently read by a single radiologist, urologist, and pathologist, respectively, in a blinded fashion. Disease maps created by each independent reader were compared and evaluated for concordance by a 5 persons committee consisting of 2 urologists, 2 pathologists, and 1 radiologist. Logistic regression for correlated data was used to assess and compare mpMRI and HS in terms of diagnostic accuracy for cancer detection. Generalized estimating equations based on binary logistic regression were used to model concordance between reader opinion and the reference standard assessment of the same lesion site or region as a function of imaging modality.

RESULTS

Data from 31/35 men enrolled in the trial were deemed to be evaluable. On evaluation of cancer localization, HS identified cancer in 36/78 (46.2%) regions of interest, as compared with 41/78 (52.6%) on mpMRI (P = 0.3968). The overall accuracy, positive predictive value, negative predictive value, and specificity for detection of disease within a region of interest were significantly better with mpMRI as compared with HS. HS detected 36/84 (42.9%) cancer foci as compared with 42/84 (50%) detected by mpMRI (P = 0.3678). Among tumors with Gleason score>6, mpMRI detected 19/22 (86.4%) whereas HS detected only 11/22 (50%, P = 0.0078). Similarly, among tumors>10mm in maximal diameter, mpMRI detected 28/34 (82.4%) whereas HS detected only 19/34 (55.9%, P = 0.0352).

CONCLUSION

In our institution, the diagnostic accuracy of HS was inferior to that of mpMRI in PCa for PCa detection and localization. Although our study warrants validation from larger cohorts, it would suggest that the HS protocol requires further refinement before clinical implementation.

Computer-aided transrectal ultrasound: does prostate HistoScanning™ improve detection performance of prostate cancer in repeat biopsies?

Background

An imaging tool providing reliable prostate cancer (PCa) detection and localization is necessary to improve common diagnostic pathway with ultrasound targeted biopsies. To determine the performance of transrectal ultrasound (TRUS) augmented by prostate HistoScanning^TM analysis (PHS) we investigated the detection of prostate cancer (PCa) foci in repeat prostate biopsies (Bx).

Methods

97 men with a mean age of 66.2 (44 – 82) years underwent PHS augmented TRUS analysis prior to a repeat Bx. Three PHS positive foci were defined in accordance with 6 bilateral prostatic sectors. Targeted Bx (tBx) limited to PHS positive foci and a systematic 14-core backup Bx (sBx) were taken. Results were correlated to biopsy outcome. Sensitivity, specificity, predictive accuracy, negative predictive value (NPV) and positive predictive value (PPV) were calculated.

Results

PCa was found in 31 of 97 (32 %) patients. Detection rate in tBx was significantly higher (p < .001). Detection rate in tBx and sBx did not differ on patient level(p ≥ 0.7). PHS sensitivity, specificity, predictive accuracy, PPV and NPV were 45 %, 83 %, 80 %, 19 % and 95 %, respectively.

Conclusions

PHS augmented TRUS identifies abnormal prostatic tissue. Although sensitivity and PPV for PCa are low, PHS information facilitates Bx targeting to vulnerable foci and results in a higher cancer detection rate. PHS targeted Bx should be considered in patients at persistent risk of PCa.

True targeting-derived prostate biopsy: HistoScanning™ remained inadequate despite advanced technical efforts

PURPOSE

To verify the reliability of HistoScanning™-based, true targeting (TT)-derived prostate biopsy.

METHODS

We relied on 40 patients suspicious for prostate cancer who underwent standard and TT-derived prostate biopsy. Sensitivity, specificity, positive predictive value, negative predictive value and the area under the curve (AUC) were assessed for the prediction of biopsy results per octant by HistoScanning™, using different HistoScanning™ signal volume cutoffs (>0, >0.2 and >0.5 ml).

RESULTS

Overall, 319 octants were analyzed. Of those, 64 (20.1 %) harbored prostate cancer. According to different HistoScanning™ signal volume cutoffs (>0, >0.2 and >0.5 ml), the AUCs for predicting biopsy results were: 0.51, 0.51 and 0.53, respectively. Similarly, the sensitivity, specificity, positive predictive and negative predictive values were: 20.7, 78.2, 17.4 and 81.6 %; 20.7, 82.0, 20.3 and 82.3 %; and 12.1, 94.6, 33.3 and 82.9 %, respectively.

CONCLUSIONS

Prediction of biopsy results based on HistoScanning™ signals and TT-derived biopsies was unreliable. Moreover, the AUC of TT-derived biopsies was low and did not improve when additional signal volume cutoffs were applied (>0.2 and >0.5 ml). We cannot recommend a variation of well-established biopsy standards or reduction in biopsy cores based on HistoScanning™ signals.

Transrectal Ultrasound (US), Contrast-enhanced US, Real-time Elastography, HistoScanning, Magnetic Resonance Imaging (MRI), and MRI-US Fusion Biopsy in the Diagnosis of Prostate Cancer

CONTEXT

Debates on overdiagnosis and overtreatment of prostate cancer (PCa) are ongoing and there is still huge uncertainty regarding misclassification of prostate biopsy results. Several imaging techniques that have emerged in recent years could overcome over- and underdiagnosis in PCa.

OBJECTIVE

To review the literature on transrectal ultrasound (TRUS)-based techniques (contrast enhancement, HistoScanning, elastography) and magnetic resonance imaging (MRI)-based techniques for a nonsystematic overview of their benefits and limitations.

EVIDENCE ACQUISITION

A comprehensive search of the PubMed database between August 2004 and August 2014 was performed. Studies assessing grayscale TRUS, contrast-enhanced (CE)-TRUS, elastography, HistoScanning, multiparametric MRI (mpMRI), and MRI-TRUS fusion biopsy were included. Publications before 2004 were included if they reported the principle or the first clinical results for these techniques.

EVIDENCE SYNTHESIS

Grayscale TRUS alone cannot detect PCa foci (detection rate 23-29%). TRUS-based (elastography) and MRI-based techniques (MRI-TRUS fusion biopsy) have significantly improved PCa diagnostics, with sensitivity of 53-74% and specificity of 72-95%. HistoScanning does not provide convincing or homogeneous results (specificity 19-82%). CE-TRUS seems to be user dependent; it is used in a low number of high-volume centers and has wide ranges for sensitivity (54-79%) and specificity (42-95%). For all the techniques reviewed, prospective multicenter studies with consistent definitions are lacking.

CONCLUSIONS

Standard grayscale TRUS is unreliable for PCa detection. Among the techniques reviewed, mpMRI and MRI-TRUS fusion biopsy seem to be suitable for enhancing PCa diagnostics. Elastography shows promising results according to the literature. CE-TRUS yields very inhomogeneous results and might not be the ideal technique for clinical practice. The value of HistoScanning must be questioned according to the literature.

PATIENT SUMMARY

New imaging modalities such as elastography and magnetic resonance imaging/transrectal ultrasound fusion biopsies have improved the detection of prostate cancer. This may lower the burden of overtreatment as a result of more precise diagnosis.

[Value of perineal HistoScanning™ template-guided prostate biopsy]

BACKGROUND

Modern imaging modalities improve prostate diagnostics.

OBJECTIVES

This study was performed to determine the outcome characteristics of biopsy procedures using the results of HistoScanning(TM) analysis (HS) for identifying prostate cancer (PCa) in patients with perineal template-guided prostate biopsy.

PATIENTS AND METHODS

A total of 104 consecutive men (mean age 69 years, mean PSA 9.9 ng/ml) underwent HS prior to the extended prostate biopsy procedure. Patients received a targeted transperineal (template-assisted) as well as a targeted transrectal prostate biopsy using HS projection reports supplemented by a standardized 14-core systematic transrectal prostate biopsy (Bx). The cancer detection rate was analyzed on the sector level and HS targeted results were correlated to biopsy outcome, sensitivity, specificity, predictive accuracy, negative predictive value (NPV) and positive predictive value (PPV).

RESULTS

Of 104 patients, 44 patients (42%) were found to have PCa. Histology detected atypical small acinar proliferation in 3 patients (2.9%), high-grade prostatic intraepithelial neoplasia in 16 (15.4%), and chronic active inflammation in 74 (71.1%), respectively. The detection rate for each region was significantly higher in HS-targeted biopsies compared to Bx. The detection rate per patient was not significantly different, although a smaller number of regions were biopsied with the targeted approach. The overall sensitivity, specificity, predictive accuracy, NPV, and PPV on the sector level were 37.2, 85.6, 78.6, 88.7 and 30.8%, respectively.

CONCLUSION

The use of HS analysis results in a higher detection rate of prostate cancer compared to common transrectal ultrasonography (TRUS)-guided Bx. This technique increases the informative value of TRUS imaging and improves the diagnostic impact at least in the targeted biopsy setting.

Quantitative ultrasound spectroscopic imaging for characterization of disease extent in prostate cancer patients

Three-dimensional quantitative ultrasound spectroscopic imaging of prostate was investigated clinically for the noninvasive detection and extent characterization of disease in cancer patients and compared to whole-mount, whole-gland histopathology of radical prostatectomy specimens. Fifteen patients with prostate cancer underwent a volumetric transrectal ultrasound scan before radical prostatectomy. Conventional-frequency (~5MHz) ultrasound images and radiofrequency data were collected from patients. Normalized power spectra were used as the basis of quantitative ultrasound spectroscopy. Specifically, color-coded parametric maps of 0-MHz intercept, midband fit, and spectral slope were computed and used to characterize prostate tissue in ultrasound images. Areas of cancer were identified in whole-mount histopathology specimens, and disease extent was correlated to that estimated from quantitative ultrasound parametric images. Midband fit and 0-MHz intercept parameters were found to be best associated with the presence of disease as located on histopathology whole-mount sections. Obtained results indicated a correlation between disease extent estimated noninvasively based on midband fit parametric images and that identified histopathologically on prostatectomy specimens, with an r(2) value of 0.71 (P<.0001). The 0-MHz intercept parameter demonstrated a lower level of correlation with histopathology. Spectral slope parametric maps offered no discrimination of disease. Multiple regression analysis produced a hybrid disease characterization model (r(2)=0.764, P<.05), implying that the midband fit biomarker had the greatest correlation with the histopathologic extent of disease. This work demonstrates that quantitative ultrasound spectroscopic imaging can be used for detecting prostate cancer and characterizing disease extent noninvasively, with corresponding gross three-dimensional histopathologic correlation.

Prostate histoscanning true targeting guided prostate biopsy: initial clinical experience

OBJECTIVE

To evaluate the feasibility of prostate histoscanning true targeting (PHS-TT) guided transrectal ultrasound (TRUS) biopsy.

METHODS

This is a prospective, single center, pilot study performed during February 2013-September 2013. All consecutive patients planned for prostate biopsy were included in the study, and all the procedure was performed by a single surgeon aided by the specialized true targeting software. Initially, the patients underwent PHS to map the abnormal areas within the prostate that were ≥0.2 cm(3). TRUS guided biopsies were performed targeting the abnormal areas with a specialized software. Additionally, routine bisextant biopsies were also taken. The final histopathology of the target cores was compared with the bisextant cores.

RESULTS

A total of 43 patients underwent combined 'targeted PHS guided' and 'standard 12 core systematic' biopsies. The mean volume of abnormal area detected by PHS is 4.3 cm(3). The overall cancer detection rate was 46.5 % (20/43) with systemic cores and target cores detecting cancer in 44 % (19/43) and 26 % (11/43), respectively. The mean % cancer/core length of the PHS-TT cores were significantly higher than the systematic cores (55.4 vs. 37.5 %. p < 0.05). In biopsy naïve patients, the cancer detection rate (43.7 % vs. 14.8 %. p = 0.06) and the cancer positivity of the cores (30.1 vs. 6.8 %. p < 0.01) of target cores were higher than those patients with prior biopsies.

CONCLUSION

PHS-TT is feasible and can be an effective tool for real-time guidance of prostate biopsies.

Using imaging biomarkers to improve the planning of radical prostatectomies

OBJECTIVES

This exploratory pilot study aimed to evaluate whether adding imaging biomarkers to conventional staging improves complete excision rates after undergoing radical prostatectomy (RP) in the United Kingdom for patients who have not undergone population prostate specific antigen screening. We primarily considered estimates of lesion volume and location based on computer-aided analysis of ultrasound (US) raw radiofrequency (RF) data acquired during trans-rectal ultrasound. The imaging analysis device used had been shown to accurately detect tumor loci within the prostate in previous studies.

METHODS AND MATERIALS

US raw RF data were collected from motorized trans-rectal ultrasound of 68 consecutive men with operable prostate cancer. In this cohort (group 1), locations and volume measurements of lesions suspected of harboring cancer on US raw RF data analysis by prostate HistoScanning, were added to conventional presurgical staging.The unexposed control group comprised 100 men who underwent conventional presurgical staging only (group 2): 50 were operated before and 50 operated after group 1 recruitment. Changes to pre-operative surgical planning and positive lateral margins of RP prostate pathological specimens were the primary outcomes. Data were collected using a Microsoft Excel database and analyzed using Stata.

RESULTS

Baseline demographics were comparable. In group 1, consideration of the additional imaging biomarkers led to changes in 27 (19.9%) operative surgical plans. Absolute rate reduction of a positive surgical margin (PSM) attributable to the imaging-biomarkers was 13.3% (P = 0.029). For stage pT3, PSM rate was reduced from 45.8% (n = 44) to 21.2% (n = 11) (P = 0.0028).

CONCLUSIONS

Obtaining quantitative measurements of preoperative imaging biomarkers appears to improve PSM rates of patients undergoing RP. The greatest PSM rate reduction was observed for pT3 tumors.

Tissue quality assessment using a novel direct elasticity assessment device (the E-finger): a cadaveric study of prostatectomy dissection

Introduction

Minimally invasive radical prostatectomy (RP) (robotic and laparoscopic), have brought improvements in the outcomes of RP due to improved views and increased degrees of freedom of surgical devices. Robotic and laparoscopic surgeries do not incorporate haptic feedback, which may result in complications secondary to inadequate tissue dissection (causing positive surgical margins, rhabdosphincter damage, etc). We developed a micro-engineered device (6 mm² sized) [E-finger]) capable of quantitative elasticity assessment, with amplitude ratio, mean ratio and phase lag representing this. The aim was to assess the utility of the device in differentiating peri-prostatic tissue types in order to guide prostate dissection.

Material and Methods

Two embalmed and 2 fresh frozen cadavers were used in the study. Baseline elasticity values were assessed in bladder, prostate and rhabdosphincter of pre-dissected embalmed cadavers using the micro-engineered device. A measurement grid was created to span from the bladder, across the prostate and onto the rhabdosphincter of fresh frozen cadavers to enable a systematic quantitative elasticity assessment of the entire area by 2 independent assessors. Tissue was sectioned along each row of elasticity measurement points, and stained with haematoxylin and eosin (H&E). Image analysis was performed with Image Pro Premier to determine the histology at each measurement point.

Results

Statistically significant differences in elasticity were identified between bladder, prostate and sphincter in both embalmed and fresh frozen cadavers (p = <0.001). Intra-class correlation (ICC) reliability tests showed good reliability (average ICC = 0.851). Sensitivity and specificity for tissue identification was 77% and 70% respectively to a resolution of 6 mm².

Conclusions

This cadaveric study has evaluated the ability of our elasticity assessment device to differentiate bladder, prostate and rhabdosphincter to a resolution of 6 mm². The results provide useful data for which to continue to examine the use of elasticity assessment devices for tissue quality assessment with the aim of giving haptic feedback to surgeons performing complex surgery.

Comparison of image-guided targeted biopsies versus systematic randomized biopsies in the detection of prostate cancer: a systematic literature review of well-designed studies

OBJECTIVE

The clinical utility of image-targeted biopsies can only be judged by a comparison of the current standard of systematic 10-12 core biopsy schemes. The aim of this review was to gather the current evidence in favor of or against targeted biopsies in the detection of prostate cancer based on well-designed, controlled studies, in order to draw clinical relevant conclusions.

SUBJECTS/PATIENTS AND METHODS

A systematic literature review was performed addressing studies that compared the prostate cancer detection rates of targeted and systematic biopsy schemes using the imaging techniques of elastography, contrast-enhanced ultrasound, histoscanning and multiparametric MRI. Only well-designed, controlled studies were included and the results summarized.

RESULTS

All imaging techniques are associated with varying results regarding better or poorer detection rates relative to systematic biopsies. No technique provides a clear trend in favor of or against image-targeted biopsies. In almost all studies, the combination of targeted and systematic biopsies provided sometimes a substantial, increase in the detection rate relative to systematic biopsies alone. MRI-targeted biopsies show no advantage in the initial biopsy setting, whereas in the repeat biopsy setting improvements in the detection rates are often observed relative to systemic biopsies.

CONCLUSION

Based on well-designed, controlled studies no clear advantage of targeted biopsies over the current standard of systematic biopsies can be observed. Therefore, targeted biopsies cannot replace systematic biopsies in the diagnosis of prostate cancer. In all indications, the combination of systematic and targeted biopsy schemes provides the highest detection rate.

Does HistoScanning™ predict positive results in prostate biopsy? A retrospective analysis of 1,188 sextants of the prostate

PURPOSE

The role of HistoScanning™ (HS) in prostate biopsy is still indeterminate. Existing literature is sparse and controversial. To provide more evidence according to that important clinical topic, we analyzed institutional data from the Martini-Clinic, Prostate Cancer Center, Hamburg.

METHODS

Patients who received prostate biopsy and who also received HS were included in the study cohort. A single examiner, blinded to pathological results, re-analyzed all HS data in accordance with sextants of the prostate. Each sextant was considered as an individual case. Corresponding results from biopsy and HS were analyzed. The area under the receiver-operating characteristic curve (AUC) for the prediction of a positive biopsy by HS was calculated. Furthermore, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were assessed according to different HS signal volume cutoffs (>0, >0.2 and >0.5 ml).

RESULTS

Overall, 198 men were identified and 1,188 sextants were analyzed. The AUC to predict positive biopsy results by HS was 0.58. Sensitivity, specificity, PPV and NPV for HS to predict positive biopsy results per sextant, depending on different HS signal volume cutoffs (>0, >0.2 and >0.5 ml) were 84.1, 27.7, 29.5 and 82.9 %, 60.9, 50.6, 28.8 and 79.7 %, and 40.1, 73.3, 33.1 and 78.8 %, respectively.

CONCLUSIONS

Positive HS signals do not accurately predict positive prostate biopsy results according to sextant analysis. We cannot recommend a variation of well-established random biopsy patterns or reduction of biopsy cores in accordance with HS signals at the moment.