Digital Pathology: A must in personalized medicine

Going digital…. it hit radiology in the 70s, ushered in by the revolutionary CAT scan. The more radiologists viewed images on monitors, the more they liked it; and in succession magnetic resonance, x-rays and mammograms joined the digital world. Over the last decade, the digital push has taken place in electronic medical records. Pathology is one of the last pieces of data to be widely digitized. However, pathology images that can be accessed anywhere and shared in seconds are becoming a no-brainer advantage when compared to the 100 year old technology of glass slides.

A key driver for digital pathology (DP) is personalized medicine, in particular the development of companion diagnostic tests that accompany an increasing number of therapeutics. The diagnostic tests being performed today on specimens in many pathology labs are determining which therapeutics a patient should receive. The most exciting development for pathologists is the ability to more precisely evaluate these companion diagnostic tests to help physicians make the optimum treatment decisions. To enable that, DP vendors are developing computer-assisted algorithms in cancer and other diseases. At BioImagene, these companion algorithms are specific applications to the companion diagnostic tests, which provide accurate and reproducible measurements for choosing the most optimum treatment.

Single Therapies Today, Combo Therapies Tomorrow

HER2/neu is definitely the flag bearer for companion diagnostic tests. Based on the quantity and pattern of the HER2/neu protein in breast cancer cells, patients are selected for Herceptin treatment. Other examples include estrogen receptor (ER) and progesterone receptor (PR) tests that help oncologists decide whether to treat breast cancer patients with tamoxifen or other anti-estrogenic therapies. In another area of oncology, epidermal growth factor receptor, or EGFR, tests are routinely performed in colorectal cancer and in some types of lung and head/neck cancer to determine whether to employ inhibitors that target EGFR.

DP also enables pathologists to view a number of tests at the same time. A variety of tests, for example HER2Neu, along with estrogen and progesterone receptor tests, are performed on one slide sample by using multiplex assays. The data then appears together on one digital view on the computer screen, differentiated by colors. For example, HER2Neu appears in green, the ER in red and the PR in blue. By using DP, pathologists can look at all in parallel, a huge aid in interpreting complex tests.

Why Adopt DP Now?

With more companion diagnostic tests on the horizon, and more algorithms in development to accompany them, why adopt DP now? The main reason is to stay current with the quickly advancing technology while the current technology provides a clear advantage to pathologists performing them. In addition, DP proves a big boost in marketing labs services, especially in anatomic pathology labs, reference and regional labs, and also community labs set up to process specimens from a variety of smaller hospitals and surgery centers.

DP offers pathologists the ability to:

• Perform more accurate, reproducible and quantitative analysis, ensuring the right treatment for the right patient. A 2007 study highlighted in both the Wall Street Journal and The New York Times showed 14-16% of traditional Her-2 tests performed to determine whether a woman should take Herceptin were false positives, while 18%-23% were false negatives.
• Obtain rapid consultations, and have multiple pathologists review important diagnoses including all new malignancies.
• Review cases, including frozen sections, from remote locations, allowing pathology practices to maximize efficiencies and minimize courier costs, shipping charges and travel between sites.
• Share pathology studies with non-pathology colleagues. Oncologists, among other clinical subspecialists, like to view the pathology, and can show patients their cancers on a computer screen, a tremendous help to patients and a tremendous service for oncologists.
• Provide better clinical decision-making. In addition to pathology reports, links to radiology reports, the patient's electronic medical record, and lab data help provide the best of care.

Dr. Ryan Cole, a board certified pathologist at Cole Diagnostics Inc. in Boise Idaho, has used DP to provide what he calls "seamless, non-delayed care to distant patients back home" while away at meetings and conferences. "The technology exists to allow that current procedure and from my experience it works. The digital pathology revolution is intriguing, unique and exciting."

Where Are We Going?

Most pathology labs today are still glass slide dependent. But looking 10 years out there is consensus that a significant portion of pathology diagnoses will be performed on a computer screen versus a microscope. Slides will continue to be produced, but, in many cases, will not be delivered to the pathologist. While DP at the present has many niche applications, the technology will support pathologists in the near future to review many if not all cases in an efficient manner on a computer monitor at a pathology workstation that provides not only digitized pathology but also access to radiology PACS, endoscopic images, the EMR, and clinical laboratory data, and other digitized information. The integration of pathology with other forms of digitized clinical information provides the pathologist with access to all relevant data on a particular patient to help the pathologist arrive at the best diagnosis.

DP also has the potential in the future to greatly assist the pathologist in a variety of tedious screening tasks such as the identification of metastatic disease in lymph nodes, microorganisms in various tissues, and abnormal cells in cytology preparations. Searching for rare events -- the "needle in the haystack" cases -- consume hours of a pathologist's valuable time. Many of these screening tasks will be automated, with algorithms created to first tag the abnormal events and then to present them to the pathologist for further study.

Overcoming the Obstacles

As in all new technology adoptions, obstacles slow down widespread adoption. In DP, each year brings major improvements. As for IT concerns, storage costs, infrastructure, and digital archives are much less a concern than a couple years ago, while a much better integration with other platforms is easing workflow concerns. Soon, pathologists will be able to access digitized images from lab information systems on a daily basis similar to the fashion in which radiologists access cases through PACS.

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Biography

Dr. Monroe is board certified by the American Board of Pathology in cytopathology, anatomic pathology and clinical pathology. He received his degrees in medicine and genetics from Harvard Medical School. He subsequently completed residency training in pathology at Stanford University and the UCLA Medical Center followed by a fellowship in cytopathology at UCLA. He has published numerous articles for peer-reviewed journals and has shared his expertise through various lectures and presentations locally and nationally.