Traditionally, pathology has been a manual process: A pathologist views a stained tissue sample on a glass slide and provides a qualitative assessment of the histology, staining pattern, and intensity of the stain in a selected area. If a second opinion was desired, the slide had to physically be transferred to another pathologist, says Jason Christiansen, PhD, senior director of Operations at HistoRx. Digital pathology tools, however, allow operators to annotate and mark up images to better communicate diagnostic background in real time. With electronic image files becoming the primary data source, the ability to produce large databases of image and diagnostic information becomes possible, Christiansen notes.
And, thanks to digital pathology, pathologists can avoid what also traditionally has been the cumbersome process of getting a second opinion. With digital pathology, those stained tissue samples on glass slides are scanned by an automated microscopy system, creating digital images that may then be viewed, analyzed, shared, and managed locally or remotely by any number of reviewers, says Ron Hagner, MS, MT(ASCP), group vice president, North America at CellaVision.
Another key advantage of digital pathology is its ability to apply image-analysis algorithms — sophisticated computer programs — to digital slides, enabling quantification of medical information, reports Ole Eichhorn, chief technology officer at Aperio. Digital pathology has had a significant positive impact on pathology consultation and medical education, as well as workflow efficiency in the laboratory — resulting in better patient care and reduced costs. Gross images, voice-to-text dictation, standardized information templates, and final slide images all help to form a deeper context for a patient story, which can be shared with clinicians and patients, adds Joel Servais, marketing manager/product manager of Digital Imaging Products at Milestone.
The acceptance of digital pathology has increased steadily over the last five years due to a progressive lowering of barriers to its adoption and an increased understanding of its utility, Christiansen says. New instrumentation and storage infrastructure initially proved to be expensive. The cost for storage has decreased and instrumentation throughput has improved, however, along with a better integration with existing laboratory workflow. Furthermore, a large number of platforms have received regulatory clearance in the last five years. With this adoption in research and clinical laboratories comes the opportunity to exploit the expanded capabilities provided by digital pathology, allowing the technology to be carried to the next level.
There needs to be a way for pathologists to process samples more efficiently, says David Fletcher-Holmes, PhD, product manager of Clinical Research and Digital Pathology Systems at Cambridge Research and Instrumentation, and digital pathology is the answer. Using a computer can save a pathologist valuable time by providing automated scoring values based upon algorithms for which he can train and then use. The ability to share virtual slides leverages the expertise of remote experts on esoteric pathologies. The ability to mine huge databases of virtual slides can provide pathologists with the ability to spot more biomarkers that indicate signs of disease, which can help save lives.
Adds Christiansen, “In medicine, there is a strong movement toward electronic patient records which encompass all the details of patient diagnosis, treatment, and care. Digital pathology methods help forward this process for the field. As radiology has moved from films to PACS, so, too, is anatomic pathology moving from glass slides to digital records.”
Furthermore, and most importantly, the advanced analytical tools and the new assays (or newly refined assays) coming out of digital pathology are providing additional information that can lead to improved patient care using objective, rational scoring methods that are not subject to the pitfalls of traditional practice, Christiansen says. The ability to accurately identify and select groups of patients for personalized treatment will only be truly realized using advanced analytical tools coupled with improved assay methodologies built on the foundation of digital pathology.
Not to be ignored are the statistics for the anticipated growth of lab testing for the baby-boomer generation and the necessity for labs to maintain quality and security with testing that will have to be supported with increased technology. New technologies will enable easier documentation of compliance with testing guidelines, development of a digital chain of evidence for patient assets, and more sophisticated patient reports for clinicians, Servais adds.
Karen Lynn is a freelance medical writer.
Today’s digital pathology offerings
Digital pathology has expanded to include image analysis of computer captured images and new technologies, which can address new hypotheses and paradigms in the medical laboratory. Some frameworks can enable rapid image analysis of whole-slide images and support immunohistochemistry quantification applications for Her2, ER, and PR; another recent advance is Food and Drug Administration clearance for manual reading of Her2 slides.
Digital pathology companies offer a cornucopia of digital-pathology equipment and technology. Here are a few recent advances designed for users to comfortably and ergonomically view digital images of glass tissue slides on a computer monitor:
- slide-scanning instruments that feature line scanning for superior image quality and rapid processing times;
- automatic area- or region-of-interest identification, robust focusing, automatic image-quality assessment, self-calibration mechanisms, fast viewing performance for digital images, quantitative image analysis, and image sharing,
- brightfield scanning systems (some with either a combined brightfield and fluorescence scanner, or a standalone fluorescence slide scanner) with automated turrets and four objectives;
- products for whole slide imaging, tissue microarrays, and image analysis and storage including an Intranet, and Internet-based data storage-and-sharing solution for teleconsultation, data management, and integration with a customer’s LIS portal;
- public interfaces for third-party systems including laboratory information systems, picture archives and communication systems, and other systems found in labs;
- incorporation of technology for genetic-pattern recognition in slide images;
- 160-slide capacity with automatic slide detection, continuous access to the slide rack, vacuum slide pick-up;
- application software designed to work in an Internet browser to support case management, and customized reporting;
- by using multiple markers in the same piece of tissue, cell-phenotyping in situ is enabled in a way not before possible, thus expanding the number and variations of protein expressions that can be analyzed; and
- gross imaging products for pathology, autopsy, and necropsy environments provide high-quality images for patient cases and aid in the creation of a chain of evidence which supports newer recommendations for better standardization and documentation.