Diagnostic validity of static telepathology supporting hospitals without local pathologists in low-income countries

The State of Telepathology in Africa in the Age of Digital Pathology Advancements: A Bibliometric Analysis and Literature Review

Telepathology emerges as a vital tool, offering significant promise for enhancing pathology services in Africa, a region historically challenged by healthcare access and resource limitations. This review explores the development, adoption, and impacts of telepathology in Africa through a comprehensive bibliometric analysis and literature review. A methodical search in PubMed for publications up to 2024 revealed 119 pertinent studies, out of which 47 met the inclusion criteria for a focused review on telepathology's role in African healthcare settings. This research has charted a clear trajectory of growing interest in telepathology, as evidenced by the annual increase in related publications and robust international collaboration. It underscores the expanding utility of telepathology in diagnostics, education, and research within Africa, particularly in domains like dermatopathology, neuropathology, and, notably, oncology. The integration of artificial intelligence into telepathology presents new frontiers for enhancing diagnostic accuracy and efficiency. However, the review also identifies persistent challenges such as infrastructural inadequacies, a shortage of skilled professionals, and regulatory hurdles. The study highlights the indispensable role of international partnerships in advancing telepathology in the region. This review proposes a strategic pivot toward "leapfrogging," an approach that allows Africa to skip traditional developmental hurdles by directly adopting cutting-edge technologies and practices.

The role of telepathology in improving cancer diagnostic and research capacity in sub-Saharan Africa

Non-communicable disease (NCD), including cancer, disproportionately affect Low- and Middle-Income Countries (LMICs). This inequity is in part due to limitations of pathology services, both human and infrastructural. While significant improvements have been made to address these gaps, creative approaches that are mindful of regional priorities, cultural differences, and unique local challenges are needed. In this perspective, we will describe the implementation of telepathology services in sub-Saharan Africa (SSA) that serve as cornerstones for direct patient care, multi-disciplinary care coordination, research programs, and building human capacity through training. Models and challenges of system implementation, sustainability, and pathologist engagement will be discussed. Using disease and site-specific examples, we will suggest metrics for quality control and improvement initiatives that are critical for providing high-quality cancer registry data and necessary for future implementation of therapeutic and interventional clinical trials.

The role of telepathology in diagnosis of pre-malignant and malignant cervical lesions: Implementation at a tertiary hospital in Northern Tanzania

Introduction

Adequate and timely access to pathology services is a key to scale up cancer control, however, there is an extremely shortage of pathologists in Tanzania. Telepathology (scanned images microscopy) has the potential to increase access to pathology services and it is increasingly being employed for primary diagnosis and consultation services. However, the experience with the use of telepathology in Tanzania is limited. We aimed to investigate the feasibility of using scanned images for primary diagnosis of pre-malignant and malignant cervical lesions by assessing its equivalency to conventional (glass slide) microscopy in Tanzania.

Methods

In this laboratory-based study, assessment of hematoxylin and eosin stained glass slides of 175 cervical biopsies were initially performed conventionally by three pathologists independently. The slides were scanned at x 40 and one to three months later, the scanned images were reviewed by the pathologists in blinded fashion. The agreement between initial and review diagnoses across participating pathologists was described and measured using Cohen’s kappa coefficient (κ).

Results

The overall concordance of diagnoses established on conventional microscopy compared to scanned images across three pathologists was 87.7%; κ = 0.54; CI (0.49–0.57).The overall agreement of diagnoses established by local pathologist on conventional microscopy compared to scanned images was 87.4%; κ = 0.73; CI (0.65–0.79). The concordance of diagnoses established by senior pathologist compared to local pathologist on conventional microscopy and scanned images was 96% and 97.7% respectively. The inter-observer agreement (κ) value were 0.93, CI (0.87–1.00) and 0.94, CI (0.88–1.00) for conventional microscopy and scanned images respectively.

Conclusions

All κ coefficients expressed good intra- and inter-observer agreement, suggesting that telepathology is sufficiently accurate for primary diagnosis in surgical pathology. The discrepancies in interpretation of pre-malignant lesions highlights the importance of p16 immunohistochemistry in definitive diagnosis in these lesions. Sustainability factors including hardware and internet connectivity are essential components to be considered before telepathology may be deemed suitable for widely use in Tanzania.

Measuring digital pathology throughput and tissue dropouts

Background:

Digital pathology operations that precede viewing by a pathologist have a substantial impact on costs and fidelity of the digital image. Scan time and file size determine throughput and storage costs, whereas tissue omission during digital capture (“dropouts”) compromises downstream interpretation. We compared how these variables differ across scanners.

Methods:

A 212 slide set randomly selected from a gynecologic-gestational pathology practice was used to benchmark scan time, file size, and image completeness. Workflows included the Hamamatsu S210 scanner (operated under default and optimized profiles) and the Leica GT450. Digital tissue dropouts were detected by the aligned overlay of macroscopic glass slide camera images (reference) with images created by the slide scanners whole slide images.

Results:

File size and scan time were highly correlated within each platform. Differences in GT450, default S210, and optimized S210 performance were seen in average file size (1.4 vs. 2.5 vs. 3.4 GB) and scan time (93 vs. 376 vs. 721 s). Dropouts were seen in 29.5% (186/631) of successful scans overall: from a low of 13.7% (29/212) for the optimized S210 profile, followed by 34.6% (73/211) for the GT450 and 40.4% (84/208) for the default profile S210 profile. Small dislodged fragments, “shards,” were dropped in 22.2% (140/631) of slides, followed by tissue marginalized at the glass slide edges, 6.2% (39/631). “Unique dropouts,” those for which no equivalent appeared elsewhere in the scan, occurred in only three slides. Of these, 67% (2/3) were “floaters” or contaminants from other cases.

Conclusions:

Scanning speed and resultant file size vary greatly by scanner type, scanner operation settings, and clinical specimen mix (tissue type, tissue area). Digital image fidelity as measured by tissue dropout frequency and dropout type also varies according to the tissue type and scanner. Dropped tissues very rarely (1/631) represent actual specimen tissues that are not represented elsewhere in the scan, so in most cases cannot alter the diagnosis. Digital pathology platforms vary in their output efficiency and image fidelity to the glass original and should be matched to the intended application.

Telepathological evaluation of paediatric histological specimens in support of a hospital in Tanzania

Background/Objective

In a project of telepathology (TP) between German pathologists and a hospital in Tanzania, trained technical assistants have uploaded digital histological images onto the internet-based platform ipath. The diagnoses from 486 paediatric specimens were analysed.

Methods

The investigation included diagnoses, either primarily done via TP or secondarily after a further workup of the paraffin-embedded tissue, which was sent to Germany for cases which could not be solved via TP. In the latter, the initial TP-diagnoses were compared with the results after re-evaluation.

Results

The median age was 11 years. The cohort comprised 390 benign diseases (80.2%) and 96 malignant diseases (19.8%). For benign diseases, the most frequent anatomic sites were lymph nodes, skin, and soft tissue, breast, and head&-neck. Frequent diagnoses were non-specific inflammations and benign tumors. In malignant diseases, the most sites were lymph nodes, skin, soft tissue, head&neck, and ovary and the most frequent diseases sarcomas and lymphomas. The paraffin embedded tissue of 179 cases (36.3%) was shipped to Germany. With the concordance analysis, we could discover the mandatory necessity for the possibility of second opinion in difficult cases.

Conclusion

An exclusively TP-support cannot meet all requirements of modern medical diagnostics. The education of local pathologists is imperative.

How can we strengthen pathology services in Cambodia?

Rapid economic growth and a changing disease burden have increased the demand for pathology services in Cambodia. This paper describes the status of pathological services and international support for pathology professionals in Cambodia, and discusses future needs for strengthening pathology services. In 2016, there were only four pathologists and 18 pathology technologists in Cambodia. A postgraduate course in pathology was created in 2015, and five residents became certified in 2018. Besides multinational support with lectures and practice for pathologists, the Japanese team provides on-the-job training for pathology technologists to improve slide preparation for diagnosis. A clinicopathological conference was introduced to strengthen the communication among pathologists, pathology technologists, and gynecologists. Although there is a long way to go to reach high quality pathological services, coordination among international partners needs to continue, as does the balance between human resource development for pathology professionals, to provide a higher level of care to local citizens.

The California Telepathology Service: UCLA's Experience in Deploying a Regional Digital Pathology Subspecialty Consultation Network

Background:

The need for extending pathology diagnostic expertise to more areas is now being met by the maturation of technology that can effectively deliver this level of care. The experience and lessons learned from our successfully deployed International Telepathology Service (ITS) to a hospital system in China guided us in starting a domestic telepathology network, the California Telepathology Service (CTS). Many of the lessons learned from the ITS project informed our decision-making for the CTS. New challenges were recognized and overcome, such as addressing the complexity and cost–benefit tradeoffs involved in setting up a digital consultation system that competes with an established conventional glass slide delivery system.

Methods:

The CTS is based on a hub-and-spoke telepathology network using Leica Biosystems whole-slide image scanners and the eSlide Manager (eSM Version 12.3.3.7055, Leica Biosystems) digital image management software solution. The service currently comprises six spoke sites (UC San Diego [UCSD], UC Irvine [UCI], UC Davis, Northridge Hospital Medical Center [NHMC], Olive View Medical Center [OVMC], and Children's Hospital Los Angeles) and one central hub site (UCLA Medical Center). So far, five sites have been validated for telepathology case consultations following established practice guidelines, and four sites (UCI, UCSD, NHMC, and OVMC) have activated the service.

Results:

For the active spoke sites, we reviewed the volume, turnaround time (TAT), and case types and evaluated for utility and value. From May 2017 to July 2018, a total of 165 cases were submitted. Of note, digital consultations were particularly advantageous for preliminary kidney biopsy diagnoses (avg TAT 0.7 day).

Conclusion:

For spoke sites, telepathology provided shortened TAT and significant financial savings over hiring faculty with expertise to support a potentially low-volume service. For the hub site, the value includes exposure to educationally valuable cases, additional caseload volume to support specialized services, and improved communication with referring facilities over traditional carrier mail. The creation of a hub-and-spoke telepathology network is an expensive undertaking, and careful consideration needs to be given to support the needs of the clinical services, acquisition and effective deployment of the appropriate equipment, network requirements, and laboratory workflows to ensure a successful and cost-effective system.

[Ten years of telepathology for a mission hospital in Tanzania]

BACKGROUND

A collaboration between a hospital in Tanzania and a German institute for pathology was initiated in 2007 with the aim of establishing a working telepathological connection using the internet-based platform iPath to transmit static histological images.

OBJECTIVES

This study aimed to describe the diagnostic spectrum evaluated in the course of an aid project in a developing country in Africa.

MATERIAL AND METHODS

A total of 5230 diagnoses were analyzed, including cases that could only be definitively concluded after a second analysis of the paraffin-embedded material in Germany. The most frequent diagnoses in the five largest diagnostic groups from 17 different anatomical locations were surveyed. In addition, cases sampled from children/young adults and rare diagnoses were assessed separately.

RESULTS

Altogether we diagnosed 2934 (56.1%) benign and 2134 (40.8%) malignant diseases. The number of cases sent to Germany for a second opinion was 734 (14%). The five most common anatomical locations were the uterine cervix (n = 1211), the prostate (n = 728), skin (n = 626), breast (n = 524), and lymph nodes (n = 340). Children comprised 504 cases (9.6%). Typical tropical diseases were only rarely seen in the whole collective of cases.

CONCLUSIONS

By means of telepathology histopathological diagnoses can be supplied in a short period of time. Difficulties occurred mainly due to the unstable staff situation on site and because the quality of sampled biopsy material was not always sufficient for further investigations. Furthermore, it became clear in the course of this aid project that a predominance of standard diagnostic findings routinely seen in the pathology of tumors and infections can be anticipated rather than exotic diseases.