Comparative Analysis Reveals Potential Utility of Digital Microscopy in the Evaluation of Peripheral Blood Smears With Some Barriers to Implementation

The use of telepathology in veterinary medicine: a scoping review

Telepathology, as a subset of teleconsulting, is pathology interpretation performed at a distance. Telepathology is not a new phenomenon, but since ~2015, significant advances in information technology and telecommunications coupled with the pandemic have led to unprecedented sophistication, accessibility, and use of telepathology in human and veterinary medicine. Furthermore, telepathology can connect veterinary practices to distant laboratories and provide support for underserved animals and communities. Through our scoping review, we provide an overview of how telepathology is being used in veterinary medicine, identify gaps in the literature, and highlight future areas of research and service development. We searched MEDLINE, CAB Abstracts, and the gray literature, and included all relevant literature. Despite the widespread use of digital microscopy in large veterinary diagnostic laboratories, we identified a paucity of literature describing the use of telepathology in veterinary medicine, with a significant gap in studies addressing the validation of whole-slide imaging for primary diagnosis. Underutilization of telepathology to support postmortem examinations conducted in the field was also identified, which indicates a potential area for service development. The use of telepathology is increasing in veterinary medicine, and pathologists must keep pace with the changing technology, ensure the validation of innovative technologies, and identify novel uses to advance the profession.

Relevance of the College of American Pathologists guideline for validating whole slide imaging for diagnostic purposes to cytopathology

Whole slide imaging (WSI) allows pathologists to view virtual versions of slides on computer monitors. With increasing adoption of digital pathology, laboratories have begun to validate their WSI systems for diagnostic purposes according to reference guidelines. Among these the College of American Pathologists (CAP) guideline includes three strong recommendations (SRs) and nine good practice statements (GPSs). To date, the application of WSI to cytopathology has been beyond the scope of the CAP guideline due to limited evidence. Herein we systematically reviewed the published literature on WSI validation studies in cytology. A systematic search was carried out in PubMed-MEDLINE and Embase databases up to November 2021 to identify all publications regarding validation of WSI in cytology. Each article was reviewed to determine if SRs and/or GPSs recommended by the CAP guideline were adequately satisfied. Of 3963 retrieved articles, 25 were included. Only 4/25 studies (16%) satisfied all three SRs, with only one publication (1/25, 4%) fulfilling all three SRs and nine GPSs. Lack of a suitable validation dataset was the main missing SR (16/25, 64%) and less than a third of the studies reported intra-observer variability data (7/25, 28%). Whilst the CAP guideline for WSI validation in clinical practice helped the widespread adoption of digital pathology, more evidence is required to routinely employ WSI for diagnostic purposes in cytopathology practice. More dedicated validation studies satisfying all SRs and/or GPSs recommended by the CAP are needed to help expedite the use of WSI for primary diagnosis in cytopathology.

Validating Whole Slide Imaging Systems for Diagnostic Purposes in Pathology

CONTEXT.—

The original guideline, "Validating Whole Slide Imaging for Diagnostic Purposes in Pathology," was published in 2013 and included 12 guideline statements. The College of American Pathologists convened an expert panel to update the guideline following standards established by the National Academies of Medicine for developing trustworthy clinical practice guidelines.

OBJECTIVE.—

To assess evidence published since the release of the original guideline and provide updated recommendations for validating whole slide imaging (WSI) systems used for diagnostic purposes.

DESIGN.—

An expert panel performed a systematic review of the literature. Frozen sections, anatomic pathology specimens (biopsies, curettings, and resections), and hematopathology cases were included. Cytology cases were excluded. Using the Grading of Recommendations Assessment, Development, and Evaluation approach, the panel reassessed and updated the original guideline recommendations.

RESULTS.—

Three strong recommendations and 9 good practice statements are offered to assist laboratories with validating WSI digital pathology systems.

CONCLUSIONS.—

Systematic review of literature following release of the 2013 guideline reaffirms the use of a validation set of at least 60 cases, establishing intraobserver diagnostic concordance between WSI and glass slides and the use of a 2-week washout period between modalities. Although all discordances between WSI and glass slide diagnoses discovered during validation need to be reconciled, laboratories should be particularly concerned if their overall WSI-glass slide concordance is less than 95%.

Diagnostic Validation of a Whole-Slide Imaging Scanner in Cytological Samples: Diagnostic Accuracy and Comparison With Light Microscopy

Digital slides created by whole-slide imaging scanners can be evaluated by pathologists located in remote sites, but the process must be validated before this technology can be applied to routine cytological diagnosis. The aim of this study was to validate a whole-slide imaging scanner for cytological samples. Sixty cytological samples, whose diagnoses were confirmed by gold-standard examinations (histology or flow cytometry), were digitalized using a whole-slide imaging scanner. Digital slides and glass slides were examined by 3 observers with different levels of cytopathological expertise. No significant differences were noted between digital and glass slides in regard to the number of cases correctly diagnosed, or the sensitivity, specificity, or diagnostic accuracy, irrespective of the observers’ expertise. The agreements between the digital slides and the gold-standard examinations were moderate to substantial, while the agreements between the glass slides and the gold-standard examinations were substantial for all 3 observers. The intraobserver agreements between digital and glass slides were substantial to almost perfect. The interobserver agreements when evaluating digital slides were moderate between observers 1 and 2 and between observers 1 and 3 while they were substantial between observers 2 and 3. In conclusion, our study demonstrated that the digital slides produced by the whole-slide imaging scanner are adequate to diagnose cytological samples and are similar among clinical pathologists with differing levels of expertise.

Live remote digital microscopy in peripheral blood smear evaluation: Intraobserver concordance and experience

INTRODUCTION

Peripheral blood smear (PBS) review is a routine laboratory test which requires pathologist's interpretation when abnormal indices, atypical cells, or critical findings are identified. Real-time remote digital microscopy (DM) can potentially facilitate rapid review when an on-site pathologist is not available. Herein, we assess intraobserver concordance of PBS evaluation with light microscopy (LM) and DM using VisionTek M6 robotic DM and TeamViewer imaging software.

METHODS

Thirty-seven de-identified PBS slides were evaluated by five reviewers. Slides were loaded on a VisionTek M6 robotic microscope at an off-site laboratory and evaluated remotely via TeamViewer software. Reviewers recorded interpretation, time required for interpretation (in minutes), imaging quality (score 0-3), and confidence of interpretation (score 0-3). Other relevant information associated with DM evaluation was also documented. Slides were subsequently evaluated using LM after washout interval. The intraobserver variation of results for impression, digital slide quality, minutes to interpretation, and confidence of interpretation was compared between DM and LM.

RESULTS

The intraobserver concordance between LM and DM was 93%, with nine discordant interpretations among 135 evaluations under each review modality, respectively. Although reviewers spent more time under DM mode (5 min/slide) than LM mode (2.5 min/slide), the reviewers felt the DM provided sufficient image quality and the confidence levels of reviewers on slide interpretation were comparable between DM (2.6/3) and LM (2.8/3).

CONCLUSION

There was a high level of intraobserver concordance and comparable interpretation confidence between DM and LM. DM can be a useful methodology for off-site pathologist's review of PBS.

Frozen section evaluation via dynamic real-time nonrobotic telepathology system in a university cancer center by resident/faculty cooperation team

Frozen section telepathology interpretation experience has been largely limited to practices with locations significantly distant from one another with sporadic need for frozen section diagnosis. In 2010, we established a real-time nonrobotic telepathology system in a very active cancer center for daily frozen section service. Herein, we evaluate its accuracy compared to direct microscopic interpretation performed in the main hospital by the same faculty and its cost-efficiency over a 1-year period. From 643 (1,416 parts) cases requiring intraoperative consultation, 333 cases (690 parts) were examined by telepathology and 310 cases (726 parts) by direct microscopy. Corresponding discrepancy rates were 2.6% (18 cases: 6 [0.9%] sampling and 12 [1.7%] diagnostic errors) and 3.2% (23 cases: 8 [1.1%] sampling and 15 [2.1%] diagnostic errors), P = .63. The sensitivity and specificity of intraoperative frozen diagnosis were 0.92 and 0.99, respectively, in telepathology and 0.90 and 0.99, respectively, in direct microscopy. There was no correlation of error incidence with postgraduate year level of residents involved in the telepathology service. Cost analysis indicated that the time saved by telepathology was $19,691.00 over 1 year of the study period, whereas the capital cost for establishing the system was $8,924.00. Thus, real-time nonrobotic telepathology is a reliable and easy-to-use tool for frozen section evaluation in busy clinical settings, especially when frozen section service involves more than one hospital, and it is cost-efficient when travel is a component of the service.