Accuracy of HistoScanning™ for the prediction of a negative surgical margin in patients undergoing radical prostatectomy

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.

"Real-time" Assessment of Surgical Margins During Radical Prostatectomy: State-of-the-Art

Histopathologic examination of the pathologic specimens using hematoxylin & eosin stains represents the backbone of the modern pathology. It is time-consuming; thus, "real-time" assessment of prostatic and periprostatic tissue has gained special interest in the diagnosis and management of prostate cancer. The current study focuses on the review of the different available techniques for "real-time" evaluation of surgical margins during radical prostatectomy (RP). We performed a comprehensive search of the Medline database to identify all the articles discussing "real-time" or intraoperative assessment of surgical margins during RP. Several filters were applied to the search to include only English articles performed on human subjects and published between January 2000 and March 2019. The search revealed several options for pathologic assessment of surgical margins including intraoperative frozen sections, confocal laser endomicroscopy, optical spectroscopy, photodynamic diagnosis, optical coherence tomography, multiphoton microscopy, structured illumination microscopy, 3D augmented reality, and ex vivo fluorescence confocal microscope. Frozen section represents the gold standard technique for real-time pathologic examinations of surgical margins during RP; however, several other options showed promising results in the initial clinical trials, and considering the rapid development in the field of molecular and cellular imaging, some of these options may serve as an alternative to frozen section.

Does Prostate HistoScanning™ accurately identify prostate cancer, measure tumour volume and assess pathological stage prior to radical prostatectomy?

Objective

The objective of this paper is to assess the ability of Prostate HistoScanning™ (PHS) to accurately identify tumour volume, index lesion characteristics and pathological stage. PHS is a novel technology employing transrectal ultrasound scanning and software analysis of radiofrequency data to produce signatures for benign and cancerous tissues. Recent reports have suggested PHS is capable of characterising the index cancer lesion and disease multifocality and detecting extraprostatic extension (EPE).

Materials and methods

The index test was preoperative PHS on patients undergoing radical prostatectomy (RP). The reference test was the whole-mount pathological analysis of the RP specimen. PHS analysis estimated total tumour volumes, tumour volumes by prostate sextant, the locations and volumes of index lesions, and the presence and location of EPE.

Results

There was no correlation between PHS and histology total tumour volume estimates (Pearson coefficient –0.099), despite accounting for specimen fixation shrinkage (Pearson coefficient –0.070), nor among 144 prostate sextants in 24 patients (Pearson coefficient 0.14). Sensitivity and specificity of PHS in detecting foci > 0.2 ml were 63% and 53%, respectively; and 37% and 71%, respectively, for foci > 0.5 ml. Pearson correlation coefficient for index lesion volumes identified at pathology vs PHS was 0.065. PHS failed to locate accurately index lesion and pathological EPE.

Conclusions

PHS fails to identify total tumour volumes, tumour volumes prostate sextant, index lesion volumes and locations, and presence and location of EPE compared to RP pathology. PHS appears unsuitable for routine diagnostic clinical use in prostate cancer.

Innovations in diagnostic imaging of localized prostate cancer

PURPOSE

In recent years, various imaging modalities have been developed to improve diagnosis, staging, and localization of early-stage prostate cancer (PCa).

METHODS

A MEDLINE literature search of the time frame between 01/2007 and 06/2013 was performed on imaging of localized PCa.

RESULTS

Conventional transrectal ultrasound (TRUS) is mainly used to guide prostate biopsy. Contrast-enhanced ultrasound is based on the assumption that PCa tissue is hypervascularized and might be better identified after intravenous injection of a microbubble contrast agent. However, results on its additional value for cancer detection are controversial. Computer-based analysis of the transrectal ultrasound signal (C-TRUS) appears to detect cancer in a high rate of patients with previous biopsies. Real-time elastography seems to have higher sensitivity, specificity, and positive predictive value than conventional TRUS. However, the method still awaits prospective validation. The same is true for prostate histoscanning, an ultrasound-based method for tissue characterization. Currently, multiparametric MRI provides improved tissue visualization of the prostate, which may be helpful in the diagnosis and targeting of prostate lesions. However, most published series are small and suffer from variations in indication, methodology, quality, interpretation, and reporting.

CONCLUSIONS

Among ultrasound-based techniques, real-time elastography and C-TRUS seem the most promising techniques. Multiparametric MRI appears to have advantages over conventional T2-weighted MRI in the detection of PCa. Despite these promising results, currently, no recommendation for the routine use of these novel imaging techniques can be made. Prospective studies defining the value of various imaging modalities are urgently needed.

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.

[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.

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.

Histoscanning has low sensitivity and specificity for seminal vesicle invasion

OBJECTIVE

To examine the accuracy of HistoScanning (HS) in detecting seminal vesicle (SV) invasion (SVI) within prostate cancer (PCa) patients.

METHODS

We relied on our prospective institutional database. Patients who received HS before radical prostatectomy were included in the study cohort. An experienced HS examiner retrospectively reanalyzed the HS data blinded to patient characteristics and pathologic results. The HS results for every single SV were compared with the corresponding findings from the final pathologic report after radical prostatectomy. An area under the receiver operating characteristic curve for the prediction of SVI by HS was calculated. Depending on HS signal volume cut-offs (>0, >0.2, and >0.5 mL), the sensitivity, specificity, positive predictive value, and negative predictive value for the prediction of SVI were assessed.

RESULTS

Overall, 131 patients and 262 SVs were assessable. Of those, 23 (17.5%) men had SVI, and 39 (14.9%) single SVs were infiltrated by tumor overall. The area under the receiver operating characteristic curve for predicting SVI by HS was 0.54. Depending on the HS signal volume cut-offs (>0, >0.2, and >0.5 mL), the sensitivity, specificity, positive predictive value, and negative predictive value for predicting SVI were 76.9%, 10.8%, 13.1%, and 72.7%; 61.5%, 24.2%, 12.4%, and 78.3%; and 46.2%, 50.2%, 14.0%, and 84.2%, respectively.

CONCLUSION

HS results did not allow a reliable prediction of SVI within PCa patients. Despite, the application of HS signal volume cut-offs (>0.2 and >0.5 mL), the prediction of SVI within PCa patients remained insufficient.

A Workflow to Improve the Alignment of Prostate Imaging with Whole-mount Histopathology

RATIONALE AND OBJECTIVES

Evaluation of prostate imaging tests against whole-mount histology specimens requires accurate alignment between radiologic and histologic data sets. Misalignment results in false-positive and -negative zones as assessed by imaging. We describe a workflow for three-dimensional alignment of prostate imaging data against whole-mount prostatectomy reference specimens and assess its performance against a standard workflow.

MATERIALS AND METHODS

Ethical approval was granted. Patients underwent motorized transrectal ultrasound (Prostate Histoscanning) to generate a three-dimensional image of the prostate before radical prostatectomy. The test workflow incorporated steps for axial alignment between imaging and histology, size adjustments following formalin fixation, and use of custom-made parallel cutters and digital caliper instruments. The control workflow comprised freehand cutting and assumed homogeneous block thicknesses at the same relative angles between pathology and imaging sections.

RESULTS

Thirty radical prostatectomy specimens were histologically and radiologically processed, either by an alignment-optimized workflow (n = 20) or a control workflow (n = 10). The optimized workflow generated tissue blocks of heterogeneous thicknesses but with no significant drifting in the cutting plane. The control workflow resulted in significantly nonparallel blocks, accurately matching only one out of four histology blocks to their respective imaging data. The image-to-histology alignment accuracy was 20% greater in the optimized workflow (P < .0001), with higher sensitivity (85% vs. 69%) and specificity (94% vs. 73%) for margin prediction in a 5 × 5-mm grid analysis.

CONCLUSIONS

A significantly better alignment was observed in the optimized workflow. Evaluation of prostate imaging biomarkers using whole-mount histology references should include a test-to-reference spatial alignment workflow.

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.

Prostate cancer detection and diagnosis: the role of MR and its comparison with other diagnostic modalities--a radiologist's perspective

It is now universally recognized that many prostate cancers are over-diagnosed and over-treated. The European Randomized Study of Screening for Prostate Cancer from 2009 evidenced that, to save one man from death from prostate cancer, over 1400 men need to be screened, and 48 need to undergo treatment. The detection of prostate cancer is traditionally based on digital rectal examination (DRE) and the measurement of serum prostate-specific antigen (PSA), followed by ultrasound-guided biopsy. The primary role of imaging for the detection and diagnosis of prostate cancer has been transrectal ultrasound (TRUS) guidance during biopsy. Traditionally, MRI has been used primarily for the staging of disease in men with biopsy-proven cancer. It has a well-established role in the detection of T3 disease, planning of radiation therapy, especially three-dimensional conformal or intensity-modulated external beam radiation therapy, and planning and guiding of interstitial seed implant or brachytherapy. New advances have now established that prostate MRI can accurately characterize focal lesions within the gland, an ability that has led to new opportunities for improved cancer detection and guidance for biopsy. Two new approaches to prostate biopsy are under investigation. Both use pre-biopsy MRI to define potential targets for sampling, and the biopsy is performed either with direct real-time MR guidance (in-bore) or MR fusion/registration with TRUS images (out-of-bore). In-bore and out-of-bore MRI-guided prostate biopsies have the advantage of using the MR target definition for the accurate localization and sampling of targets or suspicious lesions. The out-of-bore method uses combined MRI/TRUS with fusion software that provides target localization and increases the sampling accuracy of TRUS-guided biopsies by integrating prostate MRI information with TRUS. Newer parameters for each imaging modality, such as sonoelastography or shear wave elastography, contrast-enhanced ultrasound and MRI elastography, show promise to further enrich datasets.

Utility of Histoscanning™ prior to prostate biopsy for the diagnosis of prostate adenocarcinoma

OBJECTIVES

HistoScanning™ (HS) is a method of ecographic diagnosis of prostate cancer. We analyze the effectiveness of the HS realization prior to the biopsies for the prostate adenocarcinoma diagnosis.

MATERIAL AND METHODS

From August to October 2012 we have carried out a study with HS prior to the biopsies in 32 patients. In all cases sextants transrectal biopsies have been realized (two cores in each sextant) in the periphery zone. In those sextants in which there were suspicious areas with HS, the biopsies were addressed to those areas. Transperineal biopsies were added to those zones placed in the half-front or apical prostatic zone. The medium age was 63.7 years (range 40-82) with a medium PSA of 8.0 ng/ml (range 3.5-36.2) and a medium prostatic volume of 46.6cc (range 18.2-103.2). In eight cases it was the first biopsy, in 14 cases they were repetition biopsies and 10 patients had a previous diagnosis of prostate adenocarcinoma (8 in a program of active surveillance and 2 T1a in RTU of previous prostate).

RESULTS

In the 32 patients a medium of 7,5 zones were biopsied (range 6-9) with a total of 239 zones studied. There were identified a medium of 3.2 zones with suspicious areas (ZS) with HS (range 2-5) with a total of 103 ZS. In 72 zones of 25 patients it was found adenocarcinoma or PIN (2 PIN, 11 score Gleason 6, 7 score Gleason 7, 3 score Gleason 8 and 2 score Gleason 9). There were 35 positive false zones in 20 patients (11 normal parenquima and 9 chronic inflammation). Negative falses were produced in 5 zones in 5 patients (2PIN, 2 score Gleason 6 and 1 score Gleason 7) although in all 5 cases adenocarcinoma was encountered (o discovered) in other zones. The HS presented a sensibility of a 93.5% with a specificity of 79.5%. The positive predictive value was of the 67.35% with a negative predictive value of 96.5%.

CONCLUSIONS

In spite of being a selected serie, with a high rate of patients with adenocarcinoma, the exploration with HS has presented a great sensibility and a high negative predictive value. These data, although they must be confirmed in less selected series, state that the prior exploration with HS can help as in the diagnostic in the biopsies as in the follow-up of programs of active surveillance.

Comparison of transrectal prostate biopsy results with histology of transurethral resection of the prostate in men undergoing high-intensity focused ultrasound

INTRODUCTION

The aim of our study was to evaluate the significance of transurethral resection of the prostate (TURP) to detect prostate cancer (PCa). A comparison was performed of the TURP specimens of patients undergoing high-intensity focused ultrasound (HIFU) with the core biopsies.

MATERIALS AND METHODS

TURP before undergoing HIFU therapy was performed in 106 patients without neoadjuvant treatment. The resected tissue was subjected to histopathological evaluation and compared to the histological results of transrectal prostate biopsy.

RESULTS

Cancer was detected in the resected tissue of 69 patients (65%). A positive correlation of the amount of resected tissue and detection of PCa could be demonstrated in a multivariate analysis.

CONCLUSIONS

With a rate of 65% PCa detected by TURP, our data provide evidence that TURP might be suitable to detect PCa in a small group of selected patients with continuously rising PSA levels and several negative biopsies. On the other hand, these data underline/reinforce the necessity to treat the whole gland using modern treatment modalities such as HIFU and cryotherapy.