Validation Of Whole Slide Imaging Research Articles

Validation of Remote Digital Pathology based diagnostic reporting of Frozen Sections from home

BackgroundDespite the promising applications of whole-slide imaging (WSI) for frozen section (FS) diagnosis, its adoption for remote reporting is limited. ObjectiveTo assess the feasibility and performance of home-based remote digital consultation for FS diagnosis. Material & MethodCases accessioned beyond regular working hours (5 pm–10 pm) were reported simultaneously using optical microscopy (OM) and WSI. Validation of WSI for FS diagnosis from a remote site, i.e. home, was performed by 5 pathologists. Cases were scanned using a portable scanner (Grundium Ocus®40) and previewed on consumer-grade computer devices through a web-based browser (http://grundium.net). Clinical data and diagnostic reports were shared through a google spreadsheet. The diagnostic concordance, inter- and intra-observer agreement for FS diagnosis by WSI versus OM, and turnaround time (TAT), were recorded. ResultsThe overall diagnostic accuracy for OM and WSI (from home) was 98.2% (range 97%–100%) and 97.6% (range 95%–99%), respectively, when compared with the reference standard. Almost perfect inter-observer (k = 0.993) and intra-observer (k = 0.987) agreement for WSI was observed by 4 pathologists. Pathologists used consumer-grade laptops/desktops with an average screen size of 14.58 inches (range = 12.3–17.7 inches) and a network speed of 64 megabits per second (range: 10–90 Mbps). The mean diagnostic assessment time per case for OM and WSI was 1:48 min and 5:54 min, respectively. Mean TAT of 27.27 min per case was observed using WSI from home. Seamless connectivity was observed in approximately 75% of cases. ConclusionThis study validates the role of WSI for remote FS diagnosis for its safe and efficient adoption in clinical use.

Validation of whole slide imaging for frozen section diagnosis of lymph node metastasis: A retrospective study from a tertiary care hospital in Thailand

BackgroundThe use of whole slide imaging (WSI) for frozen section (FS) diagnosis is helpful, particularly in the context of pathologist shortages. However, there is minimal data on such usage in resource-limited settings. This study aims to validate the use of WSI for FS diagnosis of lymph node metastasis using a low-cost virtual microscope scanner with consumer-grade laptops at a tertiary care hospital in Thailand. MethodsFS slides were retrieved for which the clinical query was to evaluate lymph node metastasis. They were digitized by a virtual microscope scanner (MoticEasyScan, Hong Kong) using up to 40× optical magnification. Three observers with different pathology experience levels diagnosed each slide, reviewing glass slides (GS) followed by digital slides (DS) after two weeks of a wash out period. WSI and GS diagnoses were compared. The time used for scanning and diagnosis of each slide was recorded. Results295 FS slides were retrieved and digitized. The first-time successful scanning rate was 93.6 %. The mean scanning time was 2 min per slide. Both intraobserver agreement and interobserver agreement of WSI and GS diagnoses were high (Cohen's K; kappa value >0.84). The time used for DS diagnosis decreased as the observer's experience with WSI increased. ConclusionsDespite varying pathological experiences, observers using WSI provided accurate FS diagnoses of lymph node metastasis. The time required for DS diagnoses decreased with additional observer's experience with WSI. Therefore, a WSI system containing low-cost scanners and consumer-grade laptops could be used for FS services in hospital laboratories lacking pathologists.

Pathologist Concordance for Ovarian Carcinoma Subtype Classification and Identification of Relevant Histologic Features Using Microscope and Whole Slide Imaging.

Despite several studies focusing on the validation of whole slide imaging (WSI) across organ systems or subspecialties, the use of WSI for specific primary diagnosis tasks has been underexamined. To assess pathologist performance for the histologic subtyping of individual sections of ovarian carcinomas using a light microscope and WSI. A panel of 3 experienced gynecologic pathologists provided reference subtype diagnoses for 212 histologic sections from 109 ovarian carcinomas based on optical microscopy review. Two additional attending pathologists provided diagnoses and also identified the presence of a set of 8 histologic features important for ovarian tumor subtyping. Two experienced gynecologic pathologists and 2 fellows reviewed the corresponding WSI images for subtype classification and feature identification. Across pathologists specialized in gynecologic pathology, concordance with the reference diagnosis for the 5 major ovarian carcinoma subtypes was significantly higher for a pathologist reading on a microscope than each of 2 pathologists reading on WSI. Differences were primarily due to more frequent classification of mucinous carcinomas as endometrioid with WSI. Pathologists had generally low agreement in identifying histologic features important to ovarian tumor subtype classification with either an optical microscopy or WSI. This result suggests the need for refined histologic criteria for identifying such features. Interobserver agreement was particularly low for identifying intracytoplasmic mucin with WSI. Inconsistencies in evaluating nuclear atypia and mitoses with WSI were also observed. Further research is needed to specify the reasons for these diagnostic challenges and to inform users and manufacturers of WSI technology.

Rapid Validation of Whole-Slide Imaging for Primary Histopathology Diagnosis.

ObjectivesThe ongoing global severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic necessitates adaptations in the practice of surgical pathology at scale. Primary diagnosis by whole-slide imaging (WSI) is a key component that would aid departments in providing uninterrupted histopathology diagnosis and maintaining revenue streams from disruption. We sought to perform rapid validation of the use of WSI in primary diagnosis meeting recommendations of the College of American Pathologists guidelines.MethodsGlass slides from clinically reported cases from 5 participating pathologists with a preset washout period were digitally scanned and reviewed in settings identical to typical reporting. Cases were classified as concordant or with minor or major disagreement with the original diagnosis. Randomized subsampling was performed, and mean concordance rates were calculated.ResultsIn total, 171 cases were included and distributed equally among participants. For the group as a whole, the mean concordance rate in sampled cases (n = 90) was 83.6% counting all discrepancies and 94.6% counting only major disagreements. The mean pathologist concordance rate in sampled cases (n = 18) ranged from 90.49% to 97%.ConclusionsWe describe a novel double-blinded method for rapid validation of WSI for primary diagnosis. Our findings highlight the occurrence of a range of diagnostic reproducibility when deploying digital methods.

Validation of Whole Slide Imaging for primary surgical pathology diagnosis of prostate biopsies.

Whole slide imaging (WSI) is an important component of digital pathology which includes digitization of glass slides and their storage as digital images. Implementation of WSI for primary surgical pathology diagnosis is evolving, following various studies which have evaluated the feasibility of WSI technology for primary diagnosis. The present study was a single-center, observational study which included evaluation by three pathologists and aimed at assessing concordance on specialty-specific diagnosis and comparison of time taken for diagnosis on WSI and conventional light microscopy (CLM). Seventy prostate core biopsy slides (reported between January 2016 and December 2016) were scanned using Pannoramic MIDI II scanner, 3DHISTECH, Budapest, Hungary, at 20× and 40×. Sixty slides were used for validation study following training with 10 slides. Intraobserver concordance for diagnosis between the two platforms of evaluation was analyzed using Cohen's κ statistics and intraclass correlation coefficient (ICC); observation time for diagnosis was compared by Wilcoxon signed-rank test. Interpretation on WSI using 20× and 40× was comparable with no major discordance. A high level of intraobserver agreement was observed between CLM and WSI for all three observers, both for primary diagnosis (κ = 0.9) and Grade group (κ = 0.7-0.8) in cases of prostatic adenocarcinoma. The major discordance rate between CLM and WSI was 3.3%-8.3%, which reflected the expertise of the observers. The time spent for diagnosis using WSI was variable for the three pathologists. WSI is comparable to CLM and can be safely incorporated for primary histological diagnosis of prostate core biopsies.

Commentary on Validation of Whole Slide Imaging for Intraoperative Consultation During Mohs Micrographic Surgery.

Commentary on Validation of Whole Slide Imaging for Intraoperative Consultation During Mohs Micrographic Surgery.

Validation of Whole Slide Imaging for Intraoperative Consultation During Mohs Micrographic Surgery.

Validation of Whole Slide Imaging for Intraoperative Consultation During Mohs Micrographic Surgery.

Validation of whole-slide imaging in the primary diagnosis of liver biopsies in a University Hospital

BackgroundExperience in the use of whole slide imaging (WSI) for primary diagnosis is limited and there are no comprehensive reports evaluating this technology in liver biopsy specimens. AimsTo determine the accuracy of interpretation of WSI compared with conventional light microscopy (CLM) in the diagnosis of needle liver biopsies. MethodsTwo experienced liver pathologists blindly analyzed 176 consecutive biopsies from the Pathology Department at the Hospital Clinic of Barcelona. One of the observers performed the initial evaluation with CLM, and the second evaluation with WSI, whereas the second observer performed the first evaluation with WSI and the second with CLM. All slides were digitized in a Ventana iScan HT at 400× and evaluated with the Virtuoso viewer (Roche diagnostics). We used kappa statistics (κ) for two observations. ResultsIntra-observer agreement between WSI and CLM evaluations was almost perfect (96.6%, κ=0.9; 95% confidence interval [95% CI]: 0.9–1 for observer 1, and 90.3%, κ=0.9; 95%CI: 0.8-0.9 for observer 2). Both native and transplantation biopsies showed an almost perfect concordance in the diagnosis. ConclusionDiagnosis of needle liver biopsy specimens using WSI is accurate. This technology can reliably be introduced in routine diagnosis.

Digital pathology in clinical use: where are we now and what is holding us back?

Whole slide imaging is being used increasingly in research applications and in frozen section, consultation and external quality assurance practice. Digital pathology, when integrated with other digital tools such as barcoding, specimen tracking and digital dictation, can be integrated into the histopathology workflow, from specimen accession to report sign-out. These elements can bring about improvements in the safety, quality and efficiency of a histopathology department. The present paper reviews the evidence for these benefits. We then discuss the challenges of implementing a fully digital pathology workflow, including the regulatory environment, validation of whole slide imaging and the evidence for the design of a digital pathology workstation.

A multisite validation of whole slide imaging for primary diagnosis using standardized data collection and analysis

Context: Text-based reporting and manual arbitration for whole slide imaging (WSI) validation studies are labor intensive and do not allow for consistent, scalable, and repeatable data collection or analysis. Objective: The objective of this study was to establish a method of data capture and analysis using standardized codified checklists and predetermined synoptic discordance tables and to use these methods in a pilot multisite validation study. Methods and Study Design: Fifteen case report form checklists were generated from the College of American Pathology cancer protocols. Prior to data collection, all hypothetical pairwise comparisons were generated, and a level of harm was determined for each possible discordance. Four sites with four pathologists each generated 264 independent reads of 33 cases. Preestablished discordance tables were applied to determine site by site and pooled accuracy, intrareader/intramodality, and interreader intramodality error rates. Results: Over 10,000 hypothetical pair-wise comparisons were evaluated and assigned harm in discordance tables. The average difference in error rates between WSI and glass, as compared to ground truth, was 0.75% with a lower bound of 3.23% (95% confidence interval). Major discordances occurred on challenging cases, regardless of modality. The average inter-reader agreement across sites for glass was 76.5% (weighted kappa of 0.68) and for digital it was 79.1% (weighted kappa of 0.72). Conclusion: These results demonstrate the feasibility and utility of employing standardized synoptic checklists and predetermined discordance tables to gather consistent, comprehensive diagnostic data for WSI validation studies. This method of data capture and analysis can be applied in large-scale multisite WSI validations.

Validation of whole slide imaging for frozen section diagnosis in surgical pathology

Background: Whole slide imaging (WSI) using high-resolution scanners is gaining acceptance as a platform for consultation as well as for frozen section (FS) evaluation in surgical pathology. We report results of an intra-observer concordance study comparing evaluation of WSI of scanned FS microscope slides with the original interpretation of the same microscope slides after an average lag time of approximately 1-year. Methods: A total of 70 FS cases (148 microscope slides) originally interpreted by 2 pathologists were scanned at ×20 using Aperio CS2 scanner (Leica Biosystems, San Diego, CA, USA). Reports were redacted such that the study pathologists reviewed images using eSlide Manager Healthcare Network application (Leica Biosystems) accompanied by the same clinical information available at the time of original FS evaluation. Discrepancies between the original FS diagnosis and WSI diagnosis were categorized as major (impacted patient care) or minor (no impact on patient care). Results: Lymph nodes, margins for head and neck cancer resections, and arthroplasty specimens to exclude infection, were the most common FS specimens. The average wash-out interval was 380 days (range: 303–466 days). There was one major discrepancy (1.4% of 70 cases) where the original FS was interpreted as severe squamous dysplasia, and the WSI FS diagnosis was mild dysplasia. There were two minor discrepancies; one where the original FS was called focal moderate squamous dysplasia and WSI FS diagnosis was negative for dysplasia. The second case was an endometrial adenocarcinoma that was originally interpreted as Federation of Gynecology and Obstetrics (FIGO) Grade I, while the WSI FS diagnosis was FIGO Grade II. Conclusions: These findings validate and support the use of WSI to provide interpretation of FS in our network of affiliated hospitals and ambulatory surgery centers.

Validation of whole slide imaging in the primary diagnosis of gynaecological pathology in a University Hospital

AimsExperience in the use of whole slide imaging (WSI) for primary diagnosis in pathology is very limited. We aimed to determine the accuracy of interpretation of WSI compared with conventional...

Validation of Whole Slide Imaging in Pathology

Validation of whole slide imaging (WSI) is an important process for clinical practice. From a vendor perspective, validation seeks to achieve premarket approval from a regulatory agency in order for them to sell their WSI devices for an intended use (e.g., primary diagnosis). Academic validations are different, as these research studies typically result in publications reporting results of a self-defined, focused validation and their findings may not be generalizable. In general, published validation studies show good concordance for diagnoses made by WSI compared to glass slides. Clinical validation in the laboratory involves documenting the process and results of a validation study for an intended clinical use. This is typically conducted in accordance with available recommendations and/or guidelines. Validation studies comparing WSI (digital slides) to glass sides (traditional light microscopy) customarily measure concordance (agreement) between these two modalities. However, this outcome measurement can be influenced by several factors including validation study design, technology used, user training, observer variability, and case difficulty. Interobserver variability is likely to be greater than intraobserver variability, as not all pathologists may agree on certain diagnoses. Several guidelines have been developed that address WSI validation, which includes the College of American Pathologists (CAP) recommendations developed for validating WSI for diagnostic purposes. These CAP recommendations were subsequently adopted by the American Telemedicine Association (ATA) clinical guidelines for telepathology. Practical guidelines that assist pathology laboratories seeking to validate their own WSI systems for diagnostic work not only are timely but also help promote digital pathology adoption.

Validating whole slide imaging for diagnostic purposes in pathology: guideline from the College of American Pathologists Pathology and Laboratory Quality Center.

There is increasing interest in using whole slide imaging (WSI) for diagnostic purposes (primary and/or consultation). An important consideration is whether WSI can safely replace conventional light microscopy as the method by which pathologists review histologic sections, cytology slides, and/or hematology slides to render diagnoses. Validation of WSI is crucial to ensure that diagnostic performance based on digitized slides is at least equivalent to that of glass slides and light microscopy. Currently, there are no standard guidelines regarding validation of WSI for diagnostic use. To recommend validation requirements for WSI systems to be used for diagnostic purposes. The College of American Pathologists Pathology and Laboratory Quality Center convened a nonvendor panel from North America with expertise in digital pathology to develop these validation recommendations. A literature review was performed in which 767 international publications that met search term requirements were identified. Studies outside the scope of this effort and those related solely to technical elements, education, and image analysis were excluded. A total of 27 publications were graded and underwent data extraction for evidence evaluation. Recommendations were derived from the strength of evidence determined from 23 of these published studies, open comment feedback, and expert panel consensus. Twelve guideline statements were established to help pathology laboratories validate their own WSI systems intended for clinical use. Validation of the entire WSI system, involving pathologists trained to use the system, should be performed in a manner that emulates the laboratory's actual clinical environment. It is recommended that such a validation study include at least 60 routine cases per application, comparing intraobserver diagnostic concordance between digitized and glass slides viewed at least 2 weeks apart. It is important that the validation process confirm that all material present on a glass slide to be scanned is included in the digital image. Validation should demonstrate that the WSI system under review produces acceptable digital slides for diagnostic interpretation. The intention of validating WSI systems is to permit the clinical use of this technology in a manner that does not compromise patient care.

Validation of Whole Slide Imaging for Primary Diagnosis in Surgical Pathology

High-resolution scanning technology provides an opportunity for pathologists to make diagnoses directly from whole slide images (WSIs), but few studies have attempted to validate the diagnoses so obtained. To compare WSI versus microscope slide diagnoses of previously interpreted cases after a 1-year delayed re-review ("wash-out") period. An a priori power study estimated that 450 cases might be needed to demonstrate noninferiority, based on a null hypothesis: "The true difference in major discrepancies between WSI and microscope slide review is greater than 4%." Slides of consecutive cases interpreted by 2 pathologists 1 year prior were retrieved from files, and alternate cases were scanned at original magnification of ×20. Each pathologist reviewed his or her cases using either a microscope or imaging application. Independent pathologists identified and classified discrepancies; an independent statistician calculated major and minor discrepancy rates for both WSI and microscope slide review of the previously interpreted cases. The 607 cases reviewed reflected the subspecialty interests of the 2 pathologists. Study limitations include the lack of cytopathology, hematopathology, or lymphoid cases; the case mix was not enriched with difficult cases; and both pathologists had interpreted several hundred WSI cases before the study to minimize the learning curve. The major and minor discrepancy rates for WSI were 1.65% and 2.31%, whereas rates for microscope slide reviews were 0.99% and 4.93%. Based on our assumptions and study design, diagnostic review by WSI was not inferior to microscope slide review (P < .001).

Evaluation of whole slide imaging for routine surgical pathology: Looking through a broader scope

Evaluation of whole slide imaging for routine surgical pathology: Looking through a broader scope