The use of telecytology for the evaluation of thyroid nodules fine-needle aspiration biopsy specimens: a systematic review

PURPOSE

Fine needle aspiration biopsy (FNAB) is currently the gold standard for diagnosis and treatment of thyroid nodules, but the growing need for anatomic pathology services in small communities is becoming a challenge. Telecytology (TC) is defined as the electronic transmission of cytological digital images, and allows for the collection of samples, primary diagnosis, and other applications without the physical presence of a pathologist. Our aim is to systematically report, summarize, and critically analyze the most up to date applications of TC to thyroid nodules FNAB evaluation.

METHODS

We performed a systematic literature review by searching PubMed, Embase, and Cochrane Library databases. Only studies published in peer-reviewed scientific journals were included. Data were extracted using the PICO framework and critically analyzed. PRISMA guidelines were applied, and the risk of bias in the included studies was assessed using the ROBINS-I tools. The methodological quality was assessed following GRADE criteria.

RESULTS

We included 13 observational studies, resulting in a total of 3856 evaluated FNAB specimens. The majority of studies (63.6%) showed an excellent concordance rate of diagnosis via TC and conventional cytology. TC can be used to perform preliminary assessment of samples with a concordance rate ranging from 74 and 100%, showing a significant reduction of the non-diagnostic rate. Image quality was referred to as perfect or nearly perfect in most cases, regardless of telecytology technique.

CONCLUSION

Telecytology could be a valuable implementation for thyroid FNAB evaluation both for primary diagnosis and preliminary assessment of samples.

Rapid On-Site Evaluation With Telecytology Significantly Reduced Unsatisfactory Rates of Thyroid Fine-Needle Aspiration

OBJECTIVES

We evaluated telecytology rapid on-site evaluation (ROSE) for thyroid ultrasound-guided fine-needle aspiration. To the best of our knowledge, this study is the first case-control clinical trial of thyroid telecytology.

METHODS

We introduced on-site ROSE in our institution's thyroid clinic for 6 months, followed by telecytology for 12 months. Our institution's ultrasound clinic, where ROSE is not provided, was used as a control group for each period.

RESULTS

Both groups had similar initial unsatisfactory rates (thyroid clinic: 8.8%; ultrasound clinic: 8.0%) before the study began. The thyroid clinic's unsatisfactory rate was significantly reduced to 1.6% after on-site ROSE (P = .001) and to 3.8% after telecytology ROSE (P = .010), with no significant difference between on-site and telecytology ROSE periods (P > .05). The ultrasound clinic's unsatisfactory rate was unchanged for both periods. Concordance between telecytology ROSE and final adequacy was 97% (κ = 0.699).

CONCLUSIONS

Telecytology ROSE reduces unsatisfactory rates for ultrasound-guided fine-needle aspiration without compromising patient care.

V. A, Rana MH, Gurpur P, Skandarajah A, D’Ambrosio M, Ramanjinappa RD, Mohan SP, Raghavan N, Kandasarma U, N. S, Raghavan S, Hedne N, Koch F, Fletcher DA, Selvam S, Kollegal M, N. PB, Ladic L, Suresh A, Pandya HJ, Kuriakose MA. A smart tele-cytology point-of-care platform for oral cancer screening

Early detection of oral cancer necessitates a minimally invasive, tissue-specific diagnostic tool that facilitates screening/surveillance. Brush biopsy, though minimally invasive, demands skilled cyto-pathologist expertise. In this study, we explored the clinical utility/efficacy of a tele-cytology system in combination with Artificial Neural Network (ANN) based risk-stratification model for early detection of oral potentially malignant (OPML)/malignant lesion. A portable, automated tablet-based tele-cytology platform capable of digitization of cytology slides was evaluated for its efficacy in the detection of OPML/malignant lesions (n = 82) in comparison with conventional cytology and histology. Then, an image pre-processing algorithm was established to segregate cells, ANN was trained with images (n = 11,981) and a risk-stratification model developed. The specificity, sensitivity and accuracy of platform/ stratification model were computed, and agreement was examined using Kappa statistics. The tele-cytology platform, Cellscope, showed an overall accuracy of 84–86% with no difference between tele-cytology and conventional cytology in detection of oral lesions (kappa, 0.67–0.72). However, OPML could be detected with low sensitivity (18%) in accordance with the limitations of conventional cytology. The integration of image processing and development of an ANN-based risk stratification model improved the detection sensitivity of malignant lesions (93%) and high grade OPML (73%), thereby increasing the overall accuracy by 30%. Tele-cytology integrated with the risk stratification model, a novel strategy established in this study, can be an invaluable Point-of-Care (PoC) tool for early detection/screening in oral cancer. This study hence establishes the applicability of tele-cytology for accurate, remote diagnosis and use of automated ANN-based analysis in improving its efficacy.

Digital Applications in Cytopathology: Problems, Rationalizations, and Alternative Approaches

OBJECTIVE

The aim of this work was to raise awareness of problems using digital applications for examining, teaching, and applying telecytology at King Abdulaziz Medical City (KAMC), Riyadh, Saudi Arabia; University of Nebraska Medical Center (UNMC), Omaha, NE, USA; and University of Pittsburgh Medical Center (UPMC), Pittsburgh, PA, USA. The objective was to rationalize problems and propose alternative digital approaches.

STUDY DESIGN

We sought to identify solutions to improve the following: (a) interpretive examination scores at KAMC for complex cytological templates (i.e., high-grade squamous intraepithelial lesions [HSIL]) when using static digital images (SDI) of cells in regions of interest (ROI); (b) visualization of cells in 3D clusters when teaching at UNMC using 2D and 3D whole-slide imaging (WSI); and (c) visualization of cells through streaming telecytology at UPMC.

RESULTS

Composite SDI (CSDI) improved test scores for complex interpretations (i.e., HSIL) by converging diagnostic criteria from multiple ROI. Multiplane focusing through z-stacked WSI facilitated the teaching of cytological entities characterized by 3D cell clusters and consultative telecytology through robotic cell analysis.

CONCLUSIONS

Adequately visualized cytomorphology and multiplane focusing are essential for virtual cytopathology examinations, teaching, or consultative telecytology. Visualization of diagnostic criteria through 2D or 3D imaging is critical. Panoptiq panoramic WSI with integrated z-stacked video clips enables optimal applied telecytology.

The Empirical Foundations of Telepathology: Evidence of Feasibility and Intermediate Effects

INTRODUCTION

Telepathology evolved from video microscopy (i.e., "television microscopy") research in the early 1950s to video microscopy used in basic research in the biological sciences to a basic diagnostic tool in telemedicine clinical applications. Its genesis can be traced to pioneering feasibility studies regarding the importance of color and other image-based parameters for rendering diagnoses and a series of studies assessing concordance of virtual slide and light microscopy diagnoses. This article documents the empirical foundations of telepathology.

METHODS

A selective review of the research literature during the past decade (2005-2016) was conducted using robust research design and adequate sample size as criteria for inclusion.

CONCLUSIONS

The evidence regarding feasibility/acceptance of telepathology and related information technology applications has been well documented for several decades. The majority of evidentiary studies focused on intermediate outcomes, as indicated by comparability between telepathology and conventional light microscopy. A consistent trend of concordance between the two modalities was observed in terms of diagnostic accuracy and reliability. Additional benefits include use of telepathology and whole slide imaging for teaching, research, and outreach to resource-limited countries. Challenges still exist, however, in terms of use of telepathology as an effective diagnostic modality in clinical practice.

Digital cytopathology

The advancements in the fields of technology and networking have revolutionized the world including the fields of medicine and dentistry. Telemedicine and its various branches provide a broad platform to medical professionals for consultations and investigations and can also act as a valuable educational aid. This review highlights the components, methods employed, clinical applications, advantages, disadvantages of telepathology and telecytology.

Rapid on-site evaluation with dynamic telecytopathology for ultrasound-guided fine-needle aspiration of head and neck nonthyroid lesions

BACKGROUND

Rapid on-site evaluation (ROSE) at the time of ultrasound-guided fine-needle aspiration (USGFNA) of head and neck lesion is essential for obtaining adequate samples and providing the preliminary diagnosis. We summarize our experience with ROSE of USGFNA on head and neck nonthyroid lesions using telecytopathology.

MATERIALS AND METHODS

Real-time images of Diff-Quik stained cytology smears were obtained at ultrasound suite with an Olympus DP-70 digital camera attached to an Olympus CX41 microscope, and transmitted via ethernet by a cytotechnologist to a cytopathologist in cytopathology laboratory who rendered a preliminary diagnosis. Live communication was conducted with Vocera voice communication system. The ultrasound suite was located on different floor from the cytopathology laboratory. Accuracy of ROSE via telecytopathology was compared with an equal number of cases that received ROSE, prior to introduction of telecytopathology, via conventional microscopy.

RESULTS

Rapid on-site evaluation was performed on a total of 116 USGFNA of head and neck nonthyroid lesions. The telecytopathology system and conventional microscopy was used to evaluate equal number of cases (58 each). Preliminary diagnoses of benign, atypical/suspicious for malignancy, and positive for malignancy were 72.4%, 17.2% and 10.3% for telecytopathology, and 69.0%, 10.3% and 20.7% for conventional microscopy. None of the cases were deemed unsatisfactory. The overall concordance between the preliminary and final diagnoses was 94.8% for telecytopathology and 98.3% for conventional microscopy and was not statistically significant (P = 0.309). The causes of discordant preliminary and final diagnoses were mainly attributed to availability of cell block and Papanicolaou-stained slides for review or flow cytometry results for lymphoma cases at the time of final sign out.

CONCLUSIONS

Telecytopathology is comparable with conventional microscopy in ROSE of USGFNA of head and neck nonthyroid lesions.

Feasibility of dynamic telecytopathology for rapid on-site evaluation of endobronchial ultrasound-guided transbronchial fine needle aspiration

OBJECTIVE

Rapid on-site evaluation (ROSE) at the time of endobronchial ultrasound-guided transbronchial fine needle aspiration (EBUS-TBFNA) is useful in obtaining adequate samples and providing preliminary diagnosis. We present our experience with ROSE of EBUS-TBFNA using telecytopathology.

MATERIALS AND METHODS

Real-time images of Diff-Quik (Mercedes Medical, Sarasota, FL)-stained cytology smears were obtained with an Olympus (Olympus America, Center Valley, PA) digital camera attached to an Olympus CX41 microscope and transmitted via ethernet by a cytotechnologist to a cytopathologist in a cytopathology laboratory who rendered a preliminary diagnosis while communicating with an on-site cytotechnologist via the Vocera (San Jose, CA) voice communication system. The endoscopy suite was located a block away from the cytopathology laboratory. Accuracy of ROSE via telecytopathology was compared with an equal number of cases that received ROSE, prior to introduction of telecytopathology, via conventional microscopy.

RESULTS

ROSE was performed on a total of 200 EBUS-TBFNAs. The telecytopathology system and conventional microscopy were used to evaluate equal numbers of cases (100 each). Preliminary diagnoses of negative/benign, atypical/suspicious, and positive for malignancy were 58%, 14%, and 24% for telecytopathology and 57%, 10%, and 31% for conventional microscopy. Four percent of telecytopathology cases and 2% of conventional microscopy cases were deemed unsatisfactory at the time of ROSE. The overall concordance between the preliminary and final diagnoses was 96% for telecytopathology and 93% for conventional microscopy. The causes of discordant preliminary and final diagnoses could be mainly attributed to difficulty in distinguishing small cell carcinoma versus reactive lymph node due to crush artifact, atypia related to reactive bronchial epithelial cells, and availability of cell block material and Papanicolaou-stained slides for review at the time of final cytologic sign out.

CONCLUSIONS

Telecytopathology is comparable with conventional microscopy in ROSE of EBUS-TBFNA. It can serve as a valid substitute for conventional microscopy for on-site assessment of EBUS-TBFNA.

Telecytological diagnosis of space-occupying lesions of the liver

OBJECTIVE

In this study, the efficiency of telemedical consulting with regard to fine needle aspirates from space-occupying lesions (SOLs) of the liver is investigated for the first time.

STUDY DESIGN

The study includes fine needle aspirations from 62 patients, 33 with hepatocellular carcinoma (HCC) and 29 with non-hepatic tumors. Using the Internet-based iPath system, the initial pathologist submitted 1-8 images from smears and cell block sections. One consultant assessed the cytological and another one the histological images. Both made their diagnoses independent of each other. A final diagnosis was made by immunochemistry of cell block sections. The cytological images were analyzed retrospectively for the occurrence of the most typical HCC indicators. The number of these indicators was related to the initial diagnoses of the three pathologists, and possible reasons for diagnostic errors were analyzed based on this analysis.

RESULTS

The accuracy of the preliminary telemedical diagnoses regarding HCC was 82.0% for the cytological images and 87.7% for the histological images. Most of the false diagnoses occurred in tumors with unusual cytological and histological patterns.

CONCLUSIONS

Telemedical consulting is a valuable tool to obtain a second opinion. However, for improvement of the diagnosis of HCC, supplementary immunochemical tests are necessary.

Making cytological diagnoses on digital images using the iPath network

BACKGROUND

The iPath telemedicine platform Basel is mainly used for histological and cytological consultations, but also serves as a valuable learning tool.

AIM

To study the level of accuracy in making diagnoses based on still images achieved by experienced cytopathologists, to identify limiting factors, and to provide a cytological image series as a learning set.

METHOD

Images from 167 consecutive cytological specimens of different origin were uploaded on the iPath platform and evaluated by four cytopathologists. Only wet-fixed and well-stained specimens were used. The consultants made specific diagnoses and categorized each as benign, suspicious or malignant.

RESULTS

For all consultants, specificity and sensitivity regarding categorized diagnoses were 83-92 and 85-93%, respectively; the overall accuracy was 88-90%. The interobserver agreement was substantial (κ = 0.791). The lowest rate of concordance was achieved in urine and bladder washings and in the identification of benign lesions.

CONCLUSION

Using a digital image set for diagnostic purposes implies that even under optimal conditions the accuracy rate will not exceed to 80-90%, mainly because of lacking supportive immunocytochemical or molecular tests. This limitation does not disqualify digital images for teleconsulting or as a learning aid. The series of images used for the study are open to the public at http://pathorama.wordpress.com/extragenital-cytology-2013/.

Thyroid fine-needle aspiration cytology: is there a place to virtual cytology?

Telecytology has been used for education, training, and consultation. Cytological studies from gynecological, nongynecological and fine-needle aspiration cytology (FNAC) specimens (including studies of thyroid FNAC) analyzed the diagnostic accuracy and reproducibility of telecytology-based predominantly on static digital images. The aim of this study was to evaluate the diagnostic reproducibility of virtual cytology by measuring intraobserver and interobserver agreements among two cytopathologists, using the Bethesda System for Reporting Thyroid Cytopathology (BSRTC) nomenclature. 502 glass slides from 222 cases of thyroid FNAC were retrieved and scanned by a high-resolution scanner generating whole slides images (virtual cytology). Conventional and virtual cytology were analyzed by a skilled cytopathologist and the intraobserver agreement rate was 77.5% with the corresponding κ value of 0.54, suggesting a moderate agreement between both methods. A second cytopathologist analyzed the same slides only by virtual cytology and the interobserver agreement rate was 80.2% with the corresponding κ value of 0.57, suggesting a moderate agreement between both cytopathologists. The virtual cytology resulted in a higher proportion of aspirates classified as nondiagnostic (20.3 and 14.9% for the first and second cytopathologist, respectively) as compared to conventional cytology (8.1%). Regarding specific diagnostic categories as defined by the BSRTC nomenclature, the follicular lesion of undetermined significance category presented the lowest concordance rates, corresponding to 5.9% intraobserver agreement and no (0.0%) interobserver agreement. We suggest that virtual cytology can be an alternative to conventional cytology in assessment of thyroid FNAC specimens, but nondiagnostic aspirates obtained by virtual cytology should be reassessed by conventional cytology.

Feasibility of telecytopathology for rapid preliminary diagnosis of ultrasound-guided fine needle aspiration of axillary lymph nodes in a remote breast care center

Background:

In the recent years, the advances in digital methods in pathology have resulted in the use of telecytology in the immediate assessment of fine needle aspiration (FNA) specimens. However, there is a need for organ-based and body site-specific studies on the use of telecytology for the immediate assessment of FNA to evaluate its pitfalls and limitations. We present our experience with the use of telecytology for on-site evaluation of ultrasound-guided FNA (USG-FNA) of axillary lymph nodes in a remote breast care center.

Materials and Methods:

Real-time images of Diff-Quik-stained cytology smears were obtained with an Olympus digital camera attached to an Olympus CX41 microscope and transmitted via ethernet by a cytotechnologist to a pathologist who rendered preliminary diagnosis while communicating with the on-site cytotechnologist over the Vocera system. The accuracy of the preliminary diagnosis was compared with the final diagnosis, retrospectively.

Results:

A total of 39 female patients (mean age: 50.5 years) seen at the breast care center underwent USG-FNA of 44 axillary nodes. Preliminary diagnoses of benign, suspicious/malignant, and unsatisfactory were 41, 52, and 7%, respectively. Only one of the 23 cases that were initially interpreted as benign was reclassified as suspicious on final cytologic diagnosis. Seventeen of 18 suspicious/malignant cases on initial cytology corresponded with a malignant diagnosis on final cytology. One suspicious case was reclassified as benign on final cytologic diagnosis. All unsatisfactory cases remained inadequate for final cytologic interpretation. The presence of additional material in the cell block and interpretative error were the main reasons for discrepancy, accounting for the two discrepant cases.

Conclusions:

This retrospective study demonstrates that the on-site telecytology evaluation of USG-FNA of axillary lymph nodes in patients at a remote breast care center was highly accurate compared with the final cytologic evaluation. It allows pathologists to use their time more efficiently and makes on-site evaluation at a remote site possible.

A static-image telepathology system for dermatopathology consultation in East Africa: the Massachusetts General Hospital Experience

BACKGROUND

The histologic diagnosis of skin lesions in the developing world is complicated by the shortage of pathologists with subspecialty training in dermatopathology, limited access to ancillary diagnostic testing, and costly referrals for expert glass slide consultation in challenging cases.

OBJECTIVE

In this study we evaluate the feasibility of a static-image telepathology platform in Africa for performing accurate dermatopathology consultations.

METHODS

A static-image telepathology platform using the iPath server was utilized by referring pathologists in 4 African hospitals. Diagnostic interpretations were provided by Massachusetts General Hospital dermatopathologists at no cost. The diagnostic accuracy and interobserver correlation was evaluated.

RESULTS

The static histopathologic images were diagnostic in 22 of 29 (76%) cases. Diagnostic accuracy between static image and glass slide diagnosis in 22 cases was 91%, ranging from 86% to 95% according to years of dermatopathology subspecialty expertise. Comparison with the glass slides showed that the telepathology diagnosis was limited by inappropriate field selection in only one case. Interobserver concordance between two pathologists was high (K = 0.86) suggesting that this platform is easy to use with minimal training of both referring and consulting pathologists.

LIMITATIONS

Concordance between conventional microscopy and static image telepathology was performed in 22 of 29 cases for which glass slides were received. Interobserver concordance was performed for two pathologists.

CONCLUSION

Static-image telepathology is a feasible means of rendering diagnoses on dermatopathology cases and is a cost-effective technology for obtaining much-needed second opinions in resource-poor settings.

Dynamic telecytopathology for on-site preliminary diagnosis of endoscopic ultrasound-guided fine needle aspiration of pancreatic masses

We evaluated dynamic telecytopathology for on-site-evaluation of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) samples of the pancreas. Realtime images of stained cytology smears were assessed by a cytopathologist while communicating with the on-site operator by telephone. A total of 55 consecutive cases was assessed; preliminary diagnoses of benign, atypical/suspicious and positive for malignancy were 69%, 7% and 24%. We also reviewed 55 consecutive cases of EUS-guided FNA of pancreas which had had conventional microscopic on-site evaluation prior to the introduction of telecytopathology. Preliminary diagnoses of benign, atypical/suspicious and positive for malignancy were 60%, 9% and 31%. The overall concordance between the preliminary and final diagnosis was 84% for telecytopathology and 87% for conventional microscopy. Neuroendocrine neoplasms and well-differentiated adenocarcinoma were diagnostically challenging for both telecytopathology and conventional microscopy. Telecytopathology was similar in accuracy of preliminary diagnosis to conventional microscopy during EUS-FNA of pancreas.

Telecytology: Clinical applications, current challenges, and future benefits

Telecytology is the interpretation of cytology material at a distance using digital images. For more than a decade, pioneering efforts to introduce telecytology into clinical practice have been reported. A Medline search for "telecytology" and "cytology" reveals a voluminous literature, though much of what has been published to date is based on technologies that are rapidly becoming obsolete. The technological limitations of previous techniques, including the transmission of static digital images and dynamic streaming images, have limited telecytology to minor niches. The primary problem with these technologies is that the remote viewer can only see a small fraction of the material on the original slides, introducing the possibility of diagnostic error based not only on image quality but also on image selection. Remote robotic microscopy offers one possible solution to this problem, but to date has found limited acceptance, principally attributable to slow operating times. Whole slide imaging seems to be a much more promising solution, though cytology-specific literature regarding its use is still scant. The advent of whole slide imaging opens up new possibilities for telecytology by enabling high-quality images of entire cytology specimens to be available to anyone, anywhere via the Internet. Although challenges remain, especially with regard to capturing the full microscopy experience including multiple planes of focus and sharp high-powered images, rapidly advancing technology promises to overcome these limitations. Increasing application of whole slide imaging technology in surgical pathology will undoubtedly also increase its application to cytology due to the increasing affordability and practicality of the equipment as it serves a larger number of useful roles within a pathology department. The current and expanding applications of telecytology for clinical practice, education, quality assurance, and testing will be reviewed.

Telecytology in East Africa: a feasibility study of forty cases using a static imaging system

We conducted a pilot study to assess the feasibility of telecytology as a diagnostic tool in difficult cases originating from a hospital in East Africa. Forty cytology cases considered difficult by a referring pathologist were posted on a telepathology website. Six pathologists independently assessed the static images. Telecytology diagnoses were compared with the consensus diagnoses made on glass slides and also with the histogical diagnoses when available. The diagnostic agreement of the six pathologists was 71-93% and tended to be higher for pathologists with more experience. Reasons for discordance included poor image quality, presence of diagnostic cells in thick areas of smears, sampling bias and screening errors. The consensus diagnoses agreed with histological diagnoses in all 17 cases in which a biopsy was performed. Diagnostic accuracy rates (i.e. telecytology diagnosis vs. histological diagnosis) for individual pathologists were 65-88%. To ensure diagnostic accuracy both referring and consulting pathologists must have adequate training in cytology, image acquisition and image-based diagnosis and the diagnostic questions of importance must be clearly communicated by the referring pathologist when posting a case.