Microscope? No, Thanks: User Experience With Complete Digital Pathology for Routine Diagnosis

To the Editor.—Granada University Hospitals (GUH) in Granada, Spain, which comprises 2 teaching and 2 general hospitals, adopted complete digital pathology for primary diagnosis¹  in 2016, when microscopes were largely replaced by the Philips IntelliSite Pathology Solution for routine histopathology diagnosis. This system is designed for clinical diagnosis and has Food and Drug Administration clearance for primary diagnosis in the United States.²  It comprises an ultrafast scanner (UFS), a bright-field scanner capable of digitizing thirty-two 75 × 25-mm slides per hour on average at ×40 equivalent with a definition of 0.25 μm per pixel. Since the digital transition, GUH pathologists have experienced efficiency gains of between 15% and 26% more cases signed out per pathologist per year compared with the microscope era.¹ 

Despite these efficiency gains, we wanted to know our pathologists' perceptions about digital pathology, the time needed to transition to digital diagnosis, its impact on diagnostic quality and patient safety, and whether or not digital pathology is overall preferred to the optical microscope. To gather information about these topics, we conducted an anonymous survey among all 23 pathologists at GUH 2 years after the implementation of full digital pathology for primary diagnosis. The age distribution of participants is shown in Table 1, and the survey questions are listed in Table 2.

The survey results show that, when asked what percentage of glass slides were reviewed on the microscope, one-third of pathologists (8 of 23) never requested any glass slides, and the remaining two-thirds requested only between 1% and 10% of slides. The type of slides requested included those for fluorescence in situ hybridization analysis, direct immunofluorescence, and polarized light (Congo red) samples; these slide types cannot be digitized by the UFS. Pathologists diagnosed all other stains and case types on digital images.

With regard to time needed to transition from the traditional microscope-based practice to complete digital pathology after validation, 6 of 23 respondents (26% of all pathologists) reported being ready in less than 24 hours, 14 of 23 (61%) needed between 1 and 7 days, and the remaining 3 pathologists (13%) needed between 7 and 14 days. No pathologist required an adaptation period beyond 2 weeks. Also, four-fifths of pathologists (18 of 23) reported feeling better off in terms of patient safety and quality of their diagnosis when comparing digital pathology with the microscope. This was due to the integration between the laboratory information system and the use of digital tools (for measuring lesions, distance to margins, mitotic counting, etc). They also reported feeling more efficient in a digital workflow, and subjectively quantified these gains at around 20%, in agreement with the efficiency analysis previously reported.¹  When asked whether they would prefer to continue working digitally or return to the optical microscope, all 23 (100%) declared they prefer working digitally.

This survey shows that digital pathology has been universally adopted among all GUH pathologists and among all diagnostic specialties, mostly because of the digital pathology system's capabilities to help determine a routine diagnosis. It also shows that the time needed for transition is typically 1 week, and that digital pathology has resulted in subjective improvements in quality and patient safety. Remarkably, no pathologist stated a desire to return to the microscope. Therefore, the digital pathology system implemented is not only a viable substitute to conventional microscopy,³  but also a more efficient alternative, and one that users prefer to the traditional microscope.